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In order to explore the difference of aroma components of tobacco leaves before and after the synergistic treatment of bacteria and enzymes, a strain of Bacillus velezensis YUNM-4 screened from the surface of Yunyan 87 tobacco leaves and three kinds of biological enzymes (cellulase, lipase and neutral protease) were used to make a compound biological enzyme preparation, and the upper low-grade tobacco leaves were subjected to synergistic fermentation treatment. The conventional chemical components and aroma components of the treated tobacco leaves were determined by continuous flow analyzer and gas chromatography-mass spectrometry (GC-MS), respectively. Orthogonal partial least squares discriminant analysis (OPLS-DA) and independent t test (P<0. 05) were used to screen out the components with significant differences in the content of tobacco leaves before and after fermentation, and the relative odor activity value (ROAV) was used to analyze the difference in the contribution of aroma components in tobacco leaves before and after fermentation. The results showed that: 1) Compared with the control group, the total potassium, nicotine, total sugar, reducing sugar and potassium chloride ratio of the conventional chemical components of the fermented tobacco leaves reduced significantly, while the sugar-nicotine ratio increased significantly. 2) The total content of volatile aroma components after fermentation tobacco leaves significantly increased, reaching 498. 09 μg/g, an increase of 53. 7%, mainly alcohols, ketones, hydrocarbons, organic acids, furans and phenols; The OPLS-DA model had good experimental repeatability without over-fitting phenomenon. Through this model, 32 components with significant differences in content were screened out can better distinguish the differences in aroma components of tobacco leaves before and after fermentation. 3) The ROAV of 12 volatile aroma components in the fermented tobacco leaves was higher than that in the pre-fermented tobacco leaves. 4) The ROAV values of 11 components such as benzyl alcohol, phenylethyl alcohol, damascenone, β-ionone, acetophenone and dihydroactinidiolide were greater than 1, which were the key aroma components of fermented tobacco leaves, and could significantly improve the sensory quality of cigarettes.
In order to explore the difference of aroma components of tobacco leaves before and after the synergistic treatment of bacteria and enzymes, a strain of Bacillus velezensis YUNM-4 screened from the surface of Yunyan 87 tobacco leaves and three kinds of biological enzymes (cellulase, lipase and neutral protease) were used to make a compound biological enzyme preparation, and the upper low-grade tobacco leaves were subjected to synergistic fermentation treatment. The conventional chemical components and aroma components of the treated tobacco leaves were determined by continuous flow analyzer and gas chromatography-mass spectrometry (GC-MS), respectively. Orthogonal partial least squares discriminant analysis (OPLS-DA) and independent t test (P<0. 05) were used to screen out the components with significant differences in the content of tobacco leaves before and after fermentation, and the relative odor activity value (ROAV) was used to analyze the difference in the contribution of aroma components in tobacco leaves before and after fermentation. The results showed that: 1) Compared with the control group, the total potassium, nicotine, total sugar, reducing sugar and potassium chloride ratio of the conventional chemical components of the fermented tobacco leaves reduced significantly, while the sugar-nicotine ratio increased significantly. 2) The total content of volatile aroma components after fermentation tobacco leaves significantly increased, reaching 498. 09 μg/g, an increase of 53. 7%, mainly alcohols, ketones, hydrocarbons, organic acids, furans and phenols; The OPLS-DA model had good experimental repeatability without over-fitting phenomenon. Through this model, 32 components with significant differences in content were screened out can better distinguish the differences in aroma components of tobacco leaves before and after fermentation. 3) The ROAV of 12 volatile aroma components in the fermented tobacco leaves was higher than that in the pre-fermented tobacco leaves. 4) The ROAV values of 11 components such as benzyl alcohol, phenylethyl alcohol, damascenone, β-ionone, acetophenone and dihydroactinidiolide were greater than 1, which were the key aroma components of fermented tobacco leaves, and could significantly improve the sensory quality of cigarettes.
Study on the application of Maillard model reaction in the simulation of tobacco flue-curing process
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In order to study the Maillard reaction rules and products in tobacco flue-curing process, fixed and variable moisture content Maillard model reaction systems were established. The feasibility of using absorbance changes to characterize the intensity of the Maillard reaction was demonstrated through ultraviolet-visible spectroscopy and compositional analysis. Using fixed moisture content model reaction, Maillard reaction rules of leucine, phenylalanine, and proline at different tobacco curing stages were studied. Using variable moisture content model reaction, the products of three amino acids during the entire tobacco curing process were studied. The results indicated: The order of Maillard reaction rates during tobacco flue-curing process of the three amino acids was phenylalanine>leucine> > proline. The Maillard reactions of phenylalanine and leucine primarily occurred during the stem-drying stage, while significant reactions did not occur throughout the entire curing stage for proline. The products generated by the three amino acids during the curing stage were distinctly different. The main products of Leucine were isoamyl substituted pyrazines, while those of phenylalanine were various aromatic aldehydes and ketones, and no relevant products were detected for proline. The established model reaction system enables the simple and effective characterization of the stages and intensity of Maillard reactions of different amino acids during tobacco leaf curing through changes in absorbance, which holds significant application value for optimizing tobacco leaf curing processes.
In order to study the Maillard reaction rules and products in tobacco flue-curing process, fixed and variable moisture content Maillard model reaction systems were established. The feasibility of using absorbance changes to characterize the intensity of the Maillard reaction was demonstrated through ultraviolet-visible spectroscopy and compositional analysis. Using fixed moisture content model reaction, Maillard reaction rules of leucine, phenylalanine, and proline at different tobacco curing stages were studied. Using variable moisture content model reaction, the products of three amino acids during the entire tobacco curing process were studied. The results indicated: The order of Maillard reaction rates during tobacco flue-curing process of the three amino acids was phenylalanine>leucine> > proline. The Maillard reactions of phenylalanine and leucine primarily occurred during the stem-drying stage, while significant reactions did not occur throughout the entire curing stage for proline. The products generated by the three amino acids during the curing stage were distinctly different. The main products of Leucine were isoamyl substituted pyrazines, while those of phenylalanine were various aromatic aldehydes and ketones, and no relevant products were detected for proline. The established model reaction system enables the simple and effective characterization of the stages and intensity of Maillard reactions of different amino acids during tobacco leaf curing through changes in absorbance, which holds significant application value for optimizing tobacco leaf curing processes.
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The molecular structures and corresponding free radicals of the mian functional components epigallocatechin gallate (EGCG) and theaflavin in green tea and black tea were theoretically calculated by using the density functional theory (DFT) method of quantum chemistry. The differences in antioxidant activity and solvation effect between EGCG and theaflavin were analyzed using various antioxidant indicators, and the structureactivity relationship between the antioxidant activity of EGCG and theaflavin and their corresponding molecular structures was explored. The results showed that theaflavin had higher antioxidant activity than EGCG, and its frontline molecular orbital energy level ΔE(LUMO-HOMO) was only 5. 67 eV, phenol hydroxyl BDE of C7'—OH was only 321. 9 kJ/mol, IP was only 461. 4 kJ/mol, and the spin density of Cb—OH oxygen atom was only 0. 218. In nonpolar solvents, sequential proton-loss electron transfer (SPLET) is the preferred reaction mechanism. In polar solvents, single electron transfer followed by proton transfer (SET-PT) is the preferred reaction mechanism. C5'—OH of B ring may be the reactive site of EGCG, while C7'—OH of A' ring may be the reactive site of theaflavin. Therefore, theaflavin has strong antioxidant activity, and the position of the phenol hydroxyl group has a significant influence on it. The DFT method can provide a new perspective for studying the antioxidant activity of tea’s functional components.
The molecular structures and corresponding free radicals of the mian functional components epigallocatechin gallate (EGCG) and theaflavin in green tea and black tea were theoretically calculated by using the density functional theory (DFT) method of quantum chemistry. The differences in antioxidant activity and solvation effect between EGCG and theaflavin were analyzed using various antioxidant indicators, and the structureactivity relationship between the antioxidant activity of EGCG and theaflavin and their corresponding molecular structures was explored. The results showed that theaflavin had higher antioxidant activity than EGCG, and its frontline molecular orbital energy level ΔE(LUMO-HOMO) was only 5. 67 eV, phenol hydroxyl BDE of C7'—OH was only 321. 9 kJ/mol, IP was only 461. 4 kJ/mol, and the spin density of Cb—OH oxygen atom was only 0. 218. In nonpolar solvents, sequential proton-loss electron transfer (SPLET) is the preferred reaction mechanism. In polar solvents, single electron transfer followed by proton transfer (SET-PT) is the preferred reaction mechanism. C5'—OH of B ring may be the reactive site of EGCG, while C7'—OH of A' ring may be the reactive site of theaflavin. Therefore, theaflavin has strong antioxidant activity, and the position of the phenol hydroxyl group has a significant influence on it. The DFT method can provide a new perspective for studying the antioxidant activity of tea’s functional components.
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In order to solve the problems of difficult synthesis and poor stability of megastigmatrienone, four 3-oxo- α-ionol carbonates were synthesized as precursors of megastigmatrienone using α-ionone as raw material via a threestep reaction of reduction, esterification, and allylic oxidation. The synthesis conditions were optimized, and the thermal release behaviors of the synthesized compounds were studied by thermogravimetric analysis, on-line pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), and cigarette flavor release analysis. The results showed that using Cu+ as the catalyst and TBHP as the oxidant, the target compounds were successfully obtained in moderate to high yields. The weight loss interval of 3-oxo-α-ionol carbonates was approximately 160 ~ 350 ℃. At temperatures of 300 ℃, 600 ℃, and 900 ℃, these compounds could pyrolyze to release megastigmatrienone and corresponding alcoholic flavor substances. At an addition level of 0. 1%, the release amount of megastigmatrienone from the four 3-oxo-α-ionol carbonates was up to 6 times higher than that of blank cigarettes. Mechanistic studies indicated that upon heating, 3-oxo-α-ionol carbonates preferentially cleaved the allylic alcohol ester bond, followed by dehydration to generate megastigmatrienone. This process can enhance the sweet and smooth sensation of cigarette smoke, effectively mask off-flavors, and thus improve the overall quality of cigarettes.
In order to solve the problems of difficult synthesis and poor stability of megastigmatrienone, four 3-oxo- α-ionol carbonates were synthesized as precursors of megastigmatrienone using α-ionone as raw material via a threestep reaction of reduction, esterification, and allylic oxidation. The synthesis conditions were optimized, and the thermal release behaviors of the synthesized compounds were studied by thermogravimetric analysis, on-line pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), and cigarette flavor release analysis. The results showed that using Cu+ as the catalyst and TBHP as the oxidant, the target compounds were successfully obtained in moderate to high yields. The weight loss interval of 3-oxo-α-ionol carbonates was approximately 160 ~ 350 ℃. At temperatures of 300 ℃, 600 ℃, and 900 ℃, these compounds could pyrolyze to release megastigmatrienone and corresponding alcoholic flavor substances. At an addition level of 0. 1%, the release amount of megastigmatrienone from the four 3-oxo-α-ionol carbonates was up to 6 times higher than that of blank cigarettes. Mechanistic studies indicated that upon heating, 3-oxo-α-ionol carbonates preferentially cleaved the allylic alcohol ester bond, followed by dehydration to generate megastigmatrienone. This process can enhance the sweet and smooth sensation of cigarette smoke, effectively mask off-flavors, and thus improve the overall quality of cigarettes.
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To optimize the light regulation technology for tobacco leaf curing, four light sources (ultraviolet light, infrared light, red light, and white light) were used to conduct a comparative analysis of key indicators such as color difference, polyphenolic substances, and volatile components during the fresh, yellowing, browning and dry gluten stages of curing for tobacco leaves from upper, middle, and lower positions. The study explored the effects of irradiation from different light sources on the color and key chemical indicators of tobacco leaves. The results showed that after white light treatment, the color of middle-position tobacco leaves was more vivid, while after infrared light treatment, the color of upper-position tobacco leaves became darker. The total content of polyphenolic substances in upper-position tobacco leaves after infrared light treatment was higher than that in other groups. The lower-position tobacco leaves had the highest detection of volatile components, and the key substances causing differences in volatile components among the four light source groups for each position were nicotine and neophytadiene. Ultraviolet light treatment increased the content of aldehydes in tobacco leaves, infrared light treatment increased the content of esters, and white light and red light treatments increased the content of alcohols, among which the characteristic substances pentanal, ethyl benzoate, and phenethyl alcohol were significantly improved. Therefore, the four light source treatments have different degrees of influence on the color and key chemical components of tobacco leaves, providing a reference for regulating tobacco leaf quality based on light technology.
To optimize the light regulation technology for tobacco leaf curing, four light sources (ultraviolet light, infrared light, red light, and white light) were used to conduct a comparative analysis of key indicators such as color difference, polyphenolic substances, and volatile components during the fresh, yellowing, browning and dry gluten stages of curing for tobacco leaves from upper, middle, and lower positions. The study explored the effects of irradiation from different light sources on the color and key chemical indicators of tobacco leaves. The results showed that after white light treatment, the color of middle-position tobacco leaves was more vivid, while after infrared light treatment, the color of upper-position tobacco leaves became darker. The total content of polyphenolic substances in upper-position tobacco leaves after infrared light treatment was higher than that in other groups. The lower-position tobacco leaves had the highest detection of volatile components, and the key substances causing differences in volatile components among the four light source groups for each position were nicotine and neophytadiene. Ultraviolet light treatment increased the content of aldehydes in tobacco leaves, infrared light treatment increased the content of esters, and white light and red light treatments increased the content of alcohols, among which the characteristic substances pentanal, ethyl benzoate, and phenethyl alcohol were significantly improved. Therefore, the four light source treatments have different degrees of influence on the color and key chemical components of tobacco leaves, providing a reference for regulating tobacco leaf quality based on light technology.
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Based on the traditional papermaking process for reconstituted tobacco, combined with 2, 2, 6, 6- tetramethylpiperidine-1-oxide free radical (TEMPO)-mediated fiber oxidation modification technology, functional filter rods made from green and low-carbon plant fibers were prepared and applied to conventional cigarettes for sensory evaluation studies. The results showed that the optimal conditions for preparing the plant fiber-based functional filter rods were as follows: a mass ratio of softwood fiber to acetate fiber of 8:2, a TEMPO dosage of 0. 01 mmol/g, and a beating degree of (25±2) °SR. Under these conditions, the base paper of the filter rod had a basis weight of 45 g/m2, a bulk of 2. 88 cm3/g, an air permeability of 93 μm/(Pa·s), and a wet tensile index of 3. 073 N · m/g. The coated plant fiber-based functional filter rod cigarettes exhibited a circumference, roundness, hardness, and pressure drop of approximately 24. 14 mm, 0. 39 mm, 87. 2%, and 331 mm H2O, respectively, all meeting the filter rod standards of cigarette enterprises (circumference: (24 ±0.20) mm, roundness: ≤ 0. 40 mm, hardness: ≥ 82. 0%, and pressure drop: (310 ±30) mm H2O). Compared with traditional pure acetate filter rods, the total sensory evaluation score of cigarettes with coated plant fiber-based functional filter rods showed little difference, decreasing by only 2 points, while the release of harmful components in the mainstream smoke was significantly reduced. Therefore, the performance of the plant fiber-based functional filter rods prepared in this study can meet the standard requirements, which opens up a new avenue for the development of green, low-carbon, biodegradable, and flavor-enhanced cigarette filter rods.
Based on the traditional papermaking process for reconstituted tobacco, combined with 2, 2, 6, 6- tetramethylpiperidine-1-oxide free radical (TEMPO)-mediated fiber oxidation modification technology, functional filter rods made from green and low-carbon plant fibers were prepared and applied to conventional cigarettes for sensory evaluation studies. The results showed that the optimal conditions for preparing the plant fiber-based functional filter rods were as follows: a mass ratio of softwood fiber to acetate fiber of 8:2, a TEMPO dosage of 0. 01 mmol/g, and a beating degree of (25±2) °SR. Under these conditions, the base paper of the filter rod had a basis weight of 45 g/m2, a bulk of 2. 88 cm3/g, an air permeability of 93 μm/(Pa·s), and a wet tensile index of 3. 073 N · m/g. The coated plant fiber-based functional filter rod cigarettes exhibited a circumference, roundness, hardness, and pressure drop of approximately 24. 14 mm, 0. 39 mm, 87. 2%, and 331 mm H2O, respectively, all meeting the filter rod standards of cigarette enterprises (circumference: (24 ±0.20) mm, roundness: ≤ 0. 40 mm, hardness: ≥ 82. 0%, and pressure drop: (310 ±30) mm H2O). Compared with traditional pure acetate filter rods, the total sensory evaluation score of cigarettes with coated plant fiber-based functional filter rods showed little difference, decreasing by only 2 points, while the release of harmful components in the mainstream smoke was significantly reduced. Therefore, the performance of the plant fiber-based functional filter rods prepared in this study can meet the standard requirements, which opens up a new avenue for the development of green, low-carbon, biodegradable, and flavor-enhanced cigarette filter rods.
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MiSeq high-throughput sequencing and pure culture techniques were combined to analyze the microbial diversity of medicinal koji samples collected from Nanchang city, Jiangxi province, aiming to reveal the microbial composition within the koji. The results showed that the richness and diversity of bacterial taxa in the medicinal koji included in this study were significantly higher than those of the fungus. The dominant bacterial genera were Pediococcus and Levilactobacillus, with an average relative content of 38. 04% and 13. 00%, respectively. The dominant fungus genera were Candida and Saccharomycopsis, with an average relative content of 78. 30% and 17. 92%, respectively. Nine strains of bacteria isolated from medicinal koji were identified as three species: Pediococcus pentosaceus, Pediococcus acidilactici, and Bacillus licheniformis. Seven strains of fungus were identified as four species: Saccharomycopsis fibuligera, Saccharomycopsis malanga, Pichia kudriavzevii, and Saccharomyces cerevisiae.
MiSeq high-throughput sequencing and pure culture techniques were combined to analyze the microbial diversity of medicinal koji samples collected from Nanchang city, Jiangxi province, aiming to reveal the microbial composition within the koji. The results showed that the richness and diversity of bacterial taxa in the medicinal koji included in this study were significantly higher than those of the fungus. The dominant bacterial genera were Pediococcus and Levilactobacillus, with an average relative content of 38. 04% and 13. 00%, respectively. The dominant fungus genera were Candida and Saccharomycopsis, with an average relative content of 78. 30% and 17. 92%, respectively. Nine strains of bacteria isolated from medicinal koji were identified as three species: Pediococcus pentosaceus, Pediococcus acidilactici, and Bacillus licheniformis. Seven strains of fungus were identified as four species: Saccharomycopsis fibuligera, Saccharomycopsis malanga, Pichia kudriavzevii, and Saccharomyces cerevisiae.
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The flavor quality and bacterial taxa of black high-temperature Daqu (black-HTD), white hightemperature Daqu (white-HTD), and yellow high-temperature Daqu (yellow-HTD) produced by Longzhongdui wine company were analyzed using electronic sensing and MiSeq high-throughput sequencing technologies, respectively. It was found that aromatic components, alkanes and lipids were relatively abundant in the white-HTD, while sulfur compounds, alcohols, aldehydes and ketones were relatively abundant in the black-HTD, and yellowHTD exhibited intermediate levels of these aroma components between black and white-HTD. In terms of taste, black-HTD exhibited unique taste qualities, significantly surpassing white-and yellow-HTD in acidity, bitterness, astringency, richness (aftertaste of umami), aftertaste-A (aftertaste of bitter) and aftertaste-B indicators (aftertaste of astringent) (P < 0. 05). In terms of microbial composition, no significant differences in bacterial diversity were observed among the three types of HTD. However, the bacterial abundance was significantly higher in white-HTD than in black-HTD (P < 0. 05). The dominant bacterial genera in the three colors of HTD were mainly Saccharopolyspora (28. 95%), Thermoactinomyces (21. 07%), Kroppenstedtia (10. 06%), and Bacillus (8. 94%). A significant correlation was found between the microbial community structure and flavor quality of the three types of high-temperature daqu. Specifically, Kroppenstedtia showed a significant positive correlation with the response values of W1C (sensitive to aromatic hydrocarbon compounds) and W3C (sensitive to ammonia and aromatic components) (P<0. 05). Thermoactinomyces and Weissella exhibited significant positive correlations with umami indicators but significant negative correlations with sourness, astringency, aftertaste A, and aftertaste B (P< 0. 05).
The flavor quality and bacterial taxa of black high-temperature Daqu (black-HTD), white hightemperature Daqu (white-HTD), and yellow high-temperature Daqu (yellow-HTD) produced by Longzhongdui wine company were analyzed using electronic sensing and MiSeq high-throughput sequencing technologies, respectively. It was found that aromatic components, alkanes and lipids were relatively abundant in the white-HTD, while sulfur compounds, alcohols, aldehydes and ketones were relatively abundant in the black-HTD, and yellowHTD exhibited intermediate levels of these aroma components between black and white-HTD. In terms of taste, black-HTD exhibited unique taste qualities, significantly surpassing white-and yellow-HTD in acidity, bitterness, astringency, richness (aftertaste of umami), aftertaste-A (aftertaste of bitter) and aftertaste-B indicators (aftertaste of astringent) (P < 0. 05). In terms of microbial composition, no significant differences in bacterial diversity were observed among the three types of HTD. However, the bacterial abundance was significantly higher in white-HTD than in black-HTD (P < 0. 05). The dominant bacterial genera in the three colors of HTD were mainly Saccharopolyspora (28. 95%), Thermoactinomyces (21. 07%), Kroppenstedtia (10. 06%), and Bacillus (8. 94%). A significant correlation was found between the microbial community structure and flavor quality of the three types of high-temperature daqu. Specifically, Kroppenstedtia showed a significant positive correlation with the response values of W1C (sensitive to aromatic hydrocarbon compounds) and W3C (sensitive to ammonia and aromatic components) (P<0. 05). Thermoactinomyces and Weissella exhibited significant positive correlations with umami indicators but significant negative correlations with sourness, astringency, aftertaste A, and aftertaste B (P< 0. 05).
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In order to explore the practical application of native Saccharomyces cerevisiae in the fermentation of Haihong fruit wine. This study used laboratory isolation and selection of the S. cerevisiae CDJQ6-3 to prepare fermented low-alcohol Haihong fruit wine. The dynamic quality changes of low-alcohol (with an alcohol content of 5%vol) Haihong fruit wine during fermentation were studied based on conventional physicochemistry and electronic sensing technology. The results analysis showed that the contents of soluble solid, total sugar and reducing sugar and pH value of low-alcohol Haihong fruit wine showed a decreasing trend during fermentation, while the alcohol content and total acid content showed an increasing trend. In terms of color, low-alcohol Haihong fruit wine as a whole presents a bright red-yellow tone. In terms of the composition of flavor substances, the contents of volatile substances such as nitrogen oxides, sulfides, terpenoids, methane, ethanol, alkanes and organic sulfides gradually accumulated during fermentation, while the contents of aromatic substances gradually decreased. In terms of taste characteristics, the sourness and astringency of low-alcohol Haihong fruit wine increased gradually during fermentation. Compared to the later stages of fermentation (6 ~ 14), the low-alcohol Haihong fruit wine in the early stage of fermentation (1 ~ 6 d) has better quality characteristics, manifested as a higher red-greenness(a*) and aromatic substance content. At the same time, saltiness, astringency and umami aftertaste were significantly higher (P<0. 05), while the contents of nitrogen oxides, hydrogen, methane, (organic) sulfides, terpenoids, ethanol and alkanes, as well as the acidity (absolute value), bitterness and astringency were significantly lower (P < 0. 05). It can be concluded that the quality of low-alcohol Haihong fruit wine prepared by S. cerevisiae CDJQ6-3 fermentation showed more excellent quality characteristics in the early stage of fermentation.
In order to explore the practical application of native Saccharomyces cerevisiae in the fermentation of Haihong fruit wine. This study used laboratory isolation and selection of the S. cerevisiae CDJQ6-3 to prepare fermented low-alcohol Haihong fruit wine. The dynamic quality changes of low-alcohol (with an alcohol content of 5%vol) Haihong fruit wine during fermentation were studied based on conventional physicochemistry and electronic sensing technology. The results analysis showed that the contents of soluble solid, total sugar and reducing sugar and pH value of low-alcohol Haihong fruit wine showed a decreasing trend during fermentation, while the alcohol content and total acid content showed an increasing trend. In terms of color, low-alcohol Haihong fruit wine as a whole presents a bright red-yellow tone. In terms of the composition of flavor substances, the contents of volatile substances such as nitrogen oxides, sulfides, terpenoids, methane, ethanol, alkanes and organic sulfides gradually accumulated during fermentation, while the contents of aromatic substances gradually decreased. In terms of taste characteristics, the sourness and astringency of low-alcohol Haihong fruit wine increased gradually during fermentation. Compared to the later stages of fermentation (6 ~ 14), the low-alcohol Haihong fruit wine in the early stage of fermentation (1 ~ 6 d) has better quality characteristics, manifested as a higher red-greenness(a*) and aromatic substance content. At the same time, saltiness, astringency and umami aftertaste were significantly higher (P<0. 05), while the contents of nitrogen oxides, hydrogen, methane, (organic) sulfides, terpenoids, ethanol and alkanes, as well as the acidity (absolute value), bitterness and astringency were significantly lower (P < 0. 05). It can be concluded that the quality of low-alcohol Haihong fruit wine prepared by S. cerevisiae CDJQ6-3 fermentation showed more excellent quality characteristics in the early stage of fermentation.
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To effectively improve the quality of fermented jujube juice, this study investigated the effects of ultrasonic treatment on Lactobacillus plantarum CICC 20022 at different growth stages prior to inoculation into jujube juice for fermentation. Key quality parameters including viable cell count, total sugars, titratable acidity, total flavonoids, total phenolics, antioxidant capacity and β-glucosidase activity were systematically evaluated. The results indicated that compared to the control group, the viable cell count in the logarithmic phase ultrasoundtreated group was significantly increased by 1. 15 lg CFU/mL. The contents of titratable acid, total flavonoid and total phenol were elevated by 31. 25%, 54. 17% and 19. 05%, respectively. Moreover, the DPPH and ABTS+ radical scavenging activities were improved by 28. 26% and 19. 04% (P<0. 05), respectively. However, the total sugar and ascorbic acid contents exhibited a declining trend across different treatment stages. Additionally, both intracellular and extracellular β-glucosidase activities reached their peak values (0. 07 U/mL) in the logarithmic phase ultrasound-treated group. Sensory evaluation revealed no significant difference between the ultrasound-treated group and the control group (P > 0. 05). Ultrasound treatment could accelerate the formation of metabolites by directional regulation of the growth and metabolic activity of L. plantarum CICC 20022, and significantly improve the content of bioactive substances and flavor quality in fermented jujube juice.
To effectively improve the quality of fermented jujube juice, this study investigated the effects of ultrasonic treatment on Lactobacillus plantarum CICC 20022 at different growth stages prior to inoculation into jujube juice for fermentation. Key quality parameters including viable cell count, total sugars, titratable acidity, total flavonoids, total phenolics, antioxidant capacity and β-glucosidase activity were systematically evaluated. The results indicated that compared to the control group, the viable cell count in the logarithmic phase ultrasoundtreated group was significantly increased by 1. 15 lg CFU/mL. The contents of titratable acid, total flavonoid and total phenol were elevated by 31. 25%, 54. 17% and 19. 05%, respectively. Moreover, the DPPH and ABTS+ radical scavenging activities were improved by 28. 26% and 19. 04% (P<0. 05), respectively. However, the total sugar and ascorbic acid contents exhibited a declining trend across different treatment stages. Additionally, both intracellular and extracellular β-glucosidase activities reached their peak values (0. 07 U/mL) in the logarithmic phase ultrasound-treated group. Sensory evaluation revealed no significant difference between the ultrasound-treated group and the control group (P > 0. 05). Ultrasound treatment could accelerate the formation of metabolites by directional regulation of the growth and metabolic activity of L. plantarum CICC 20022, and significantly improve the content of bioactive substances and flavor quality in fermented jujube juice.
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In order to develop diversified apple juice concentrate natural flavors and improve the functional focus of the products, the apple juice concentrate was finely processed by using multi-stage membrane separation, and the apple characteristic flavor groups with outstanding characteristics were located by sensory evaluation. The obtained characteristic flavor groups were recombined. The pyrolytic products of recombined products with better sensory effects were analyzed by using Py-GC/MS. The results showed that: Four groups were obtained by three stages membrane separation, among which the sensory effects of 50 nm retention solution, 50 kDa retention solution and 2 nm retention solution showed distinct characteristics. By adjusting the proportions of the three characteristic flavor groups, recombinant products can be obtained with an effect superior to that of apple juice concentrate before separation. The pyrolytic products of preferred recombined products are mainly composed of heterocyclic compounds and cyclopentanone derivative, including caramel, sweet, fruit and other aroma types. This study provides a technical reference for the fine processing of natural tobacco flavors.
In order to develop diversified apple juice concentrate natural flavors and improve the functional focus of the products, the apple juice concentrate was finely processed by using multi-stage membrane separation, and the apple characteristic flavor groups with outstanding characteristics were located by sensory evaluation. The obtained characteristic flavor groups were recombined. The pyrolytic products of recombined products with better sensory effects were analyzed by using Py-GC/MS. The results showed that: Four groups were obtained by three stages membrane separation, among which the sensory effects of 50 nm retention solution, 50 kDa retention solution and 2 nm retention solution showed distinct characteristics. By adjusting the proportions of the three characteristic flavor groups, recombinant products can be obtained with an effect superior to that of apple juice concentrate before separation. The pyrolytic products of preferred recombined products are mainly composed of heterocyclic compounds and cyclopentanone derivative, including caramel, sweet, fruit and other aroma types. This study provides a technical reference for the fine processing of natural tobacco flavors.
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To address the corrosion issue in the collection pipelines of natural alkali brine, a composite anticorrosion coating system (EP +PDMS@ SiO2) was developed using epoxy resin (EP) and polydimethylsiloxane (PDMS) as matrix materials, with octadecyltrichlorosilane (OTS)-modified nano-silica (n-SiO2) particles as filler materials. The corrosion resistance of the coating was evaluated through Tafel polarization analysis, electrochemical impedance spectroscopy (EIS), and weight loss method. Results showed that the addition amount of n-SiO2 particles and modifier OTS were the key influencing factors, and the optimal addition amount was 2.1 g and 0.5 ~ 1.0 mL, respectively. When applied to N80 steel coupons, the optimized EP +PDMS@ SiO2 coating reduced the self-corrosion current by three orders of magnitude and increased charge transfer resistance by three orders of magnitude. The corrosion rate decreased from 2.004 4% to 0.029 2%. This advancement holds the anti-corrosion coating with n-SiO2 particles modified by OTS (EP + PDMS @ SiO2) had a significant effect on inhibiting the corrosion of natural alkali brine collection and transportation pipelines.
To address the corrosion issue in the collection pipelines of natural alkali brine, a composite anticorrosion coating system (EP +PDMS@ SiO2) was developed using epoxy resin (EP) and polydimethylsiloxane (PDMS) as matrix materials, with octadecyltrichlorosilane (OTS)-modified nano-silica (n-SiO2) particles as filler materials. The corrosion resistance of the coating was evaluated through Tafel polarization analysis, electrochemical impedance spectroscopy (EIS), and weight loss method. Results showed that the addition amount of n-SiO2 particles and modifier OTS were the key influencing factors, and the optimal addition amount was 2.1 g and 0.5 ~ 1.0 mL, respectively. When applied to N80 steel coupons, the optimized EP +PDMS@ SiO2 coating reduced the self-corrosion current by three orders of magnitude and increased charge transfer resistance by three orders of magnitude. The corrosion rate decreased from 2.004 4% to 0.029 2%. This advancement holds the anti-corrosion coating with n-SiO2 particles modified by OTS (EP + PDMS @ SiO2) had a significant effect on inhibiting the corrosion of natural alkali brine collection and transportation pipelines.
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In this study, the effects of selenomethionine on the in vitro digestibility of myofibrillar protein (MP) of pearl gentian grouper were studied by using a static in vitro digestion model to simulate gastric and intestinal digestion. The results showed as follows: after simulated gastric and intestinal digestion, the selenium content of high-level selenomethionine group (Y2 group) (0.130 mg/kg, 0.072 mg/kg) was significantly higher than that of control group (C group) and low-level selenomethionine group (Y1 group) (P < 0.05). However, the carbonyl content (2.02 nmol/mg, 2.59 nmol/mg), dityrosine content (3962 a. u. , 4062 a. u.), thiobarbituric acid (TBA) value (0.31 mg/kg, 0.32 mg/kg), and particle size (365 nm, 357 nm) of Y2 group were significantly lower than those in C group and Y1 group (P < 0.05). Besides, the UV absorption peaks and endogenous fluorescence intensities of the Y2 group were higher. The results showed that high-level selenomethionine delayed MP′s oxidation and denaturation process,and better maintained the structure of MP during digestion. The in vitro digestibility (62.19%, 67.25%) and the degree of hydrolysis (0.31 mmol/g, 0.34 mmol/g)of the Y1 group were significantly higher than those of the C group and Y2 group (P < 0.05). In conclusion, the supplementation of selenomethionine not only improves the antioxidant capacity of MP but also improves its in vitro digestibility, indicating that selenomethionine has potential application in improving the nutritional quality and stability of fish protein.
In this study, the effects of selenomethionine on the in vitro digestibility of myofibrillar protein (MP) of pearl gentian grouper were studied by using a static in vitro digestion model to simulate gastric and intestinal digestion. The results showed as follows: after simulated gastric and intestinal digestion, the selenium content of high-level selenomethionine group (Y2 group) (0.130 mg/kg, 0.072 mg/kg) was significantly higher than that of control group (C group) and low-level selenomethionine group (Y1 group) (P < 0.05). However, the carbonyl content (2.02 nmol/mg, 2.59 nmol/mg), dityrosine content (3962 a. u. , 4062 a. u.), thiobarbituric acid (TBA) value (0.31 mg/kg, 0.32 mg/kg), and particle size (365 nm, 357 nm) of Y2 group were significantly lower than those in C group and Y1 group (P < 0.05). Besides, the UV absorption peaks and endogenous fluorescence intensities of the Y2 group were higher. The results showed that high-level selenomethionine delayed MP′s oxidation and denaturation process,and better maintained the structure of MP during digestion. The in vitro digestibility (62.19%, 67.25%) and the degree of hydrolysis (0.31 mmol/g, 0.34 mmol/g)of the Y1 group were significantly higher than those of the C group and Y2 group (P < 0.05). In conclusion, the supplementation of selenomethionine not only improves the antioxidant capacity of MP but also improves its in vitro digestibility, indicating that selenomethionine has potential application in improving the nutritional quality and stability of fish protein.
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Two different barley polyphenols were prepared by fermentation (Lactiplantibacillus plantarum dy-1) and enzymatic hydrolysis (sulfatase), respectively. The phenolic compounds composition of fermented barley polyphenols (FBP) and enzymatic hydrolysis barley polyphenols (EBP) were analyzed. The antioxidant abilities and lipid-lowering effects of FBP and EBP were further investigated. The results indicated that total phenol contents of EBP and FBP were 78.35 μg GAE/mL and 146.56 μg GAE/mL, respectively. The absolute contents of vanillin, benzoic acid, 2, 4-dihydroxybenzoic acid, epicatechin and salicylic acid were significantly different between EBP and FBP. Under the condition of the same total phenol content, vanillin, chlorogenic acid, and gallic acid are characteristic components of the EBP while benzoic acid, 3, 4-dimethoxybenzoic acid and epicatechin are characteristic components of FBP. Compared with EBP, the DPPH and ABTS+ free radical scavenging rates of FBP were increased by 36.8% and 13.3%. At 20 μg GAE/mL total phenol content, both FBP and EBP effectively reduced the accumulation of lipid droplets, and reduced the triglyceride content by 23.3% and 27.9%, respectively, in Caenorhabditis elegans. In terms of lipid-lowering mechanism, both FBP and EBP could promote the movement of C. elegans to accelerate its lipid consumption and inhibit the abnormal activation of the SBP-1 signaling pathway. The effect of EBP on the insulin/insulin-like growth factor signaling pathway was more significant than that of FBP (P< 0.05). In conclusion, when total phenol content is the same, the composition differences of barley polyphenols could significantly affect their antioxidant ability and lipid-lowering effect.
Two different barley polyphenols were prepared by fermentation (Lactiplantibacillus plantarum dy-1) and enzymatic hydrolysis (sulfatase), respectively. The phenolic compounds composition of fermented barley polyphenols (FBP) and enzymatic hydrolysis barley polyphenols (EBP) were analyzed. The antioxidant abilities and lipid-lowering effects of FBP and EBP were further investigated. The results indicated that total phenol contents of EBP and FBP were 78.35 μg GAE/mL and 146.56 μg GAE/mL, respectively. The absolute contents of vanillin, benzoic acid, 2, 4-dihydroxybenzoic acid, epicatechin and salicylic acid were significantly different between EBP and FBP. Under the condition of the same total phenol content, vanillin, chlorogenic acid, and gallic acid are characteristic components of the EBP while benzoic acid, 3, 4-dimethoxybenzoic acid and epicatechin are characteristic components of FBP. Compared with EBP, the DPPH and ABTS+ free radical scavenging rates of FBP were increased by 36.8% and 13.3%. At 20 μg GAE/mL total phenol content, both FBP and EBP effectively reduced the accumulation of lipid droplets, and reduced the triglyceride content by 23.3% and 27.9%, respectively, in Caenorhabditis elegans. In terms of lipid-lowering mechanism, both FBP and EBP could promote the movement of C. elegans to accelerate its lipid consumption and inhibit the abnormal activation of the SBP-1 signaling pathway. The effect of EBP on the insulin/insulin-like growth factor signaling pathway was more significant than that of FBP (P< 0.05). In conclusion, when total phenol content is the same, the composition differences of barley polyphenols could significantly affect their antioxidant ability and lipid-lowering effect.
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In order to investigate the relationship between the viscosity of cigarette ash and the ash integrity of cigarette, a method was established to determine the macroscopic viscosity factor (MVI) of cigarette ash by using optical microrheometer. The MVI and ash value, gray value and ash holding capacity of different brands of cigarettes were determined, andthe relationship between cigarette ash MVI and ash integrity of cigarette was studied through correlation analysis The results show that the stability of MVI curve can be greatly improved by using flour as the stabilizer to prepare the mixed sample of soot/flour, which meets the requirement of distinguishing the viscosity difference of different brands of cigarette ash. The Logistic function can fit the MVI curve well, and its determination coefficient is above 0.99. The MVI of cigarette ash was positively correlated with ash value and gray value of cigarette pack, and the visual effect of ash column became worse with the increase of MVI. Therefore, appropriate reduction of soot MVI is beneficial to improve the ash integrity of cigarette.
In order to investigate the relationship between the viscosity of cigarette ash and the ash integrity of cigarette, a method was established to determine the macroscopic viscosity factor (MVI) of cigarette ash by using optical microrheometer. The MVI and ash value, gray value and ash holding capacity of different brands of cigarettes were determined, andthe relationship between cigarette ash MVI and ash integrity of cigarette was studied through correlation analysis The results show that the stability of MVI curve can be greatly improved by using flour as the stabilizer to prepare the mixed sample of soot/flour, which meets the requirement of distinguishing the viscosity difference of different brands of cigarette ash. The Logistic function can fit the MVI curve well, and its determination coefficient is above 0.99. The MVI of cigarette ash was positively correlated with ash value and gray value of cigarette pack, and the visual effect of ash column became worse with the increase of MVI. Therefore, appropriate reduction of soot MVI is beneficial to improve the ash integrity of cigarette.
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Abstract:
No rapid method existed for detecting blend ratios on production lines, hyperspectral imaging technology and machine learning methods were used to collect spectral data from mixed tobacco with different blend ratios. The effects of single and combined preprocessing techniques on model performance were explored. Regression models were established using partial least squares regression ( PLSR) and support vector machine regression ( SVR). Feature wavelength selection was performed with least angle regression (LARS), successive projections algorithm (SPA), competitive adaptive reweighted sampling ( CARS), and genetic algorithm ( GA) to build simplified models. The results showed that preprocessing methods, either individually or combined, affected model accuracy. The combined wavelet transform and SG filtering ( Wave + SG) method reduced mean absolute percentage error (MAPE) by 1. 2 percentage points compared to raw data. The Wave+SG-GA-PLSR model performed best, with MAPE of 1. 415% and 1. 531% for the training and test sets of two-component blends, respectively. This method was also applicable to multi-component blends, with MAPE in three-component and four-component blends below 8. 3615%. Hyperspectral imaging combined with machine learning accurately predicted the proportions of components in mixed tobacco, providing a reference for online monitoring and quality control in cigarette production.
No rapid method existed for detecting blend ratios on production lines, hyperspectral imaging technology and machine learning methods were used to collect spectral data from mixed tobacco with different blend ratios. The effects of single and combined preprocessing techniques on model performance were explored. Regression models were established using partial least squares regression ( PLSR) and support vector machine regression ( SVR). Feature wavelength selection was performed with least angle regression (LARS), successive projections algorithm (SPA), competitive adaptive reweighted sampling ( CARS), and genetic algorithm ( GA) to build simplified models. The results showed that preprocessing methods, either individually or combined, affected model accuracy. The combined wavelet transform and SG filtering ( Wave + SG) method reduced mean absolute percentage error (MAPE) by 1. 2 percentage points compared to raw data. The Wave+SG-GA-PLSR model performed best, with MAPE of 1. 415% and 1. 531% for the training and test sets of two-component blends, respectively. This method was also applicable to multi-component blends, with MAPE in three-component and four-component blends below 8. 3615%. Hyperspectral imaging combined with machine learning accurately predicted the proportions of components in mixed tobacco, providing a reference for online monitoring and quality control in cigarette production.
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Abstract:
To explore novel methods for improving the gel properties of myofibrillar protein (MP) emulsion gels under low salt condition, pre-emulsified plant oil emulsion was first prepared using the complex of chitin particle (CP) and water-soluble proanthocyanidin (PC), and then mixed with MP to prepare MP emulsion gels. The gel properties of MP emulsion gels were studied under low-salt conditions (0. 3 mol/L NaCl). It was found that under low NaCl conditions, CP and PC could synergistically improve the gel properties of MP emulsion gels. Namely, the gel strength (226. 79 g) and water holding capacity (97. 64%) of the CP-PC(3/2)-MP emulsion gel prepared by combining CP and PC in a ratio of 3:2 were higher than that of other samples. This was because CP-PC (3/2) complex had lower interfacial tension and Zeta-potential, and the droplets stabilized by the complex were smaller than those stabilized by CP alone, resulting in a more compact network structure in the CP-PC (3/2)-MP emulsion gel. Therefore, preparing emulsified plant oil by combining CP and PC was an effective method to improve the quality of emulsified meat products under low-salt conditions.
To explore novel methods for improving the gel properties of myofibrillar protein (MP) emulsion gels under low salt condition, pre-emulsified plant oil emulsion was first prepared using the complex of chitin particle (CP) and water-soluble proanthocyanidin (PC), and then mixed with MP to prepare MP emulsion gels. The gel properties of MP emulsion gels were studied under low-salt conditions (0. 3 mol/L NaCl). It was found that under low NaCl conditions, CP and PC could synergistically improve the gel properties of MP emulsion gels. Namely, the gel strength (226. 79 g) and water holding capacity (97. 64%) of the CP-PC(3/2)-MP emulsion gel prepared by combining CP and PC in a ratio of 3:2 were higher than that of other samples. This was because CP-PC (3/2) complex had lower interfacial tension and Zeta-potential, and the droplets stabilized by the complex were smaller than those stabilized by CP alone, resulting in a more compact network structure in the CP-PC (3/2)-MP emulsion gel. Therefore, preparing emulsified plant oil by combining CP and PC was an effective method to improve the quality of emulsified meat products under low-salt conditions.
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Abstract:
In order to understand the internal mechanism of the difference in the sensory quality of filler tobacco leaves after fermentation in Yunnan, taking the filler tobacco leaves of different grades (B1,X1,C1,C2,C3,C4) after fermentation as the research object. The sensory quality of different grades of filler tobacco leaves was evaluated, and their metabolome were determined with the help of GC-MS technology, and the principal component analysis(PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and KEGG metabolic pathway enrichment analysis were used for comparative analysis of differences between groups. The results showed that the C1 had more aroma, less irritation, and more aftertaste than others. There were 123 kinds of significantly differential metabolites among different grades of filler tobacco leaves, and 35 kinds of significantly differential metabolites among different grades of filler tobacco leaves, mainly heterocyclic compounds, aldehydes, ethers, carboxylic acids and aromatic compounds. Among them, (E)-butyl-2-enonitrile was a highly abundant and significantly differential metabolite in the four comparison groups with the participation of C1, and the three metabolic pathways of cyanoamino acid metabolism, aromatic compound degradation and butyric acid metabolism were significantly different in the comparison groups with the participation of C1. The (E)-buta-2-enonitrile may cause differences in metabolites of different grades of filler tobacco leaves through the accumulation and action of metabolites which related to the above three metabolic pathways, and finally cause differences in the sensory quality of different grades of filler tobacco leaves after fermentation in Yunnan.
In order to understand the internal mechanism of the difference in the sensory quality of filler tobacco leaves after fermentation in Yunnan, taking the filler tobacco leaves of different grades (B1,X1,C1,C2,C3,C4) after fermentation as the research object. The sensory quality of different grades of filler tobacco leaves was evaluated, and their metabolome were determined with the help of GC-MS technology, and the principal component analysis(PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and KEGG metabolic pathway enrichment analysis were used for comparative analysis of differences between groups. The results showed that the C1 had more aroma, less irritation, and more aftertaste than others. There were 123 kinds of significantly differential metabolites among different grades of filler tobacco leaves, and 35 kinds of significantly differential metabolites among different grades of filler tobacco leaves, mainly heterocyclic compounds, aldehydes, ethers, carboxylic acids and aromatic compounds. Among them, (E)-butyl-2-enonitrile was a highly abundant and significantly differential metabolite in the four comparison groups with the participation of C1, and the three metabolic pathways of cyanoamino acid metabolism, aromatic compound degradation and butyric acid metabolism were significantly different in the comparison groups with the participation of C1. The (E)-buta-2-enonitrile may cause differences in metabolites of different grades of filler tobacco leaves through the accumulation and action of metabolites which related to the above three metabolic pathways, and finally cause differences in the sensory quality of different grades of filler tobacco leaves after fermentation in Yunnan.
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Abstract:
To develop a novel tobacco flavoring, low-grade tobacco leaves were enzymatically treated and then co-extracted with dried rose petals. The extract was prepared using an organic solvent heating reflux method. Single-factor and response surface experiments were conducted to optimize the co-extraction parameters, including ethanol volume fraction, mixing ratio of tobacco powder to rose powder, and material ratio. The differences in aroma components between individually extracted and co-extracted samples were compared, and their effects on cigarette flavoring were analyzed. The results showed that the optimal enzymatic hydrolysis conditions for low-grade tobacco leaves were: enzymatic hydrolysis temperature of 50 ℃, enzymatic hydrolysis time of 6 h, and enzyme addition of 150 U / g of tobacco. The factors influencing the content of aroma compounds were ranked as follows: ethanol volume fraction> mixing ratio of tobacco powder to rose powder> material ratio. The optimal extraction conditions were determined as: ethanol volume fraction of 69%, mixing ratio (tobacco powder:rose powder) of 1. 8 ∶1, and material ratio of 1 ∶35. The volatile components detected in the rose sample, tobacco powder sample, and co-extracted sample were 44, 47, and 64, respectively, with total volatile contents of 325. 19 μg / g, 1289. 6 μg / g, and 1642. 89 μg / g, respectively. The co-extracted sample exhibited significantly higher levels of alcohols, esters, aldehydes, and ketones compared to individually extracted samples, while the nicotine content was reduced. When the co-extracted sample under optimal conditions was applied to cigarettes, the sensory quality of the cigarettes improved significantly. The cigarettes displayed enhanced aroma quality with floral and sweet notes, a richer and fuller fragrance, reduced irritation, and a cleaner, more comfortable aftertaste. This study demonstrates the potential of utilizing enzymatically treated low-grade tobacco leaves and rose petals for developing high-quality tobacco flavorings with improved sensory characteristics.
To develop a novel tobacco flavoring, low-grade tobacco leaves were enzymatically treated and then co-extracted with dried rose petals. The extract was prepared using an organic solvent heating reflux method. Single-factor and response surface experiments were conducted to optimize the co-extraction parameters, including ethanol volume fraction, mixing ratio of tobacco powder to rose powder, and material ratio. The differences in aroma components between individually extracted and co-extracted samples were compared, and their effects on cigarette flavoring were analyzed. The results showed that the optimal enzymatic hydrolysis conditions for low-grade tobacco leaves were: enzymatic hydrolysis temperature of 50 ℃, enzymatic hydrolysis time of 6 h, and enzyme addition of 150 U / g of tobacco. The factors influencing the content of aroma compounds were ranked as follows: ethanol volume fraction> mixing ratio of tobacco powder to rose powder> material ratio. The optimal extraction conditions were determined as: ethanol volume fraction of 69%, mixing ratio (tobacco powder:rose powder) of 1. 8 ∶1, and material ratio of 1 ∶35. The volatile components detected in the rose sample, tobacco powder sample, and co-extracted sample were 44, 47, and 64, respectively, with total volatile contents of 325. 19 μg / g, 1289. 6 μg / g, and 1642. 89 μg / g, respectively. The co-extracted sample exhibited significantly higher levels of alcohols, esters, aldehydes, and ketones compared to individually extracted samples, while the nicotine content was reduced. When the co-extracted sample under optimal conditions was applied to cigarettes, the sensory quality of the cigarettes improved significantly. The cigarettes displayed enhanced aroma quality with floral and sweet notes, a richer and fuller fragrance, reduced irritation, and a cleaner, more comfortable aftertaste. This study demonstrates the potential of utilizing enzymatically treated low-grade tobacco leaves and rose petals for developing high-quality tobacco flavorings with improved sensory characteristics.
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To obtain functional acyl sugar acyltransferase NtASAT2 of Nicotiana tabacum L., bioinformatic methods were applied to analyze and predict the sequences and structure of NtASAT2. The gene of NtASAT2 was cloned, prokaryotic expressed, and then purified. T prokaryotic expressed, and then purified. The function of the recombinant protein was verified through enzymatic catalysis. The results showed that in the secondary structure of NtASAT2, α-helices and random coils account for a large proportion with 39. 04% and 41. 13%, respectively. The amino acid sequence of NtASAT2 was highly similar to that of sticky tobacco NacASAT2. The content of soluble NtASAT2 in the recombinant protein expressed by prokaryotic cell BL21 (DE3) was relatively low, and the affinity of NtASAT2 to nickel column was weak. After purification, only a small amount of the target protein was obtained. In enzymatic reaction systems containing substrates, NtASAT2 showed enzyme activity and catalyzed the formation of sucrose diesters. The research results could provide a theoretical basis for the application of acyl sugar acyltransferase in enzymatic synthesis of sucrose esters.
To obtain functional acyl sugar acyltransferase NtASAT2 of Nicotiana tabacum L., bioinformatic methods were applied to analyze and predict the sequences and structure of NtASAT2. The gene of NtASAT2 was cloned, prokaryotic expressed, and then purified. T prokaryotic expressed, and then purified. The function of the recombinant protein was verified through enzymatic catalysis. The results showed that in the secondary structure of NtASAT2, α-helices and random coils account for a large proportion with 39. 04% and 41. 13%, respectively. The amino acid sequence of NtASAT2 was highly similar to that of sticky tobacco NacASAT2. The content of soluble NtASAT2 in the recombinant protein expressed by prokaryotic cell BL21 (DE3) was relatively low, and the affinity of NtASAT2 to nickel column was weak. After purification, only a small amount of the target protein was obtained. In enzymatic reaction systems containing substrates, NtASAT2 showed enzyme activity and catalyzed the formation of sucrose diesters. The research results could provide a theoretical basis for the application of acyl sugar acyltransferase in enzymatic synthesis of sucrose esters.
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Abstract:
Aiming at the key issues of the development and utilization of tobacco biological resources for non-cigarette manufacturing, the current status of foreign technology research and development is sorted out from the aspects of extraction of tobacco active substances and utilization of fiber materials, pointing out that: the active components of tobacco include nicotine, cannabinoid alcohol, polyphenols, proteins, tetraacyl sucrose esters and tobacco tissues (chloroplasts, mitochondria), etc.. Among these, the content and added value of nicotine, chlorogenic acid and cannabinoid alcohol are relatively high, and the extraction technology is more simple. These components have a significant market potential in the fields of pesticides, pharmaceuticals, and tobacco product additives, and have already been widely commercialized abroad. The utilization of fiber materials includes animal feed, fibrous material (paper, fiberboard, particleboard, nitrocellulose), oligosaccharides and biochar fertilizers. The primary directions for large-scale utilization of these materials are the production of biochar-based organic fertilizers, paper, and fiberboard, which are supported by relatively mature technologies. However, the cost associated with these processes remains relatively high, and there have been initial explorations into industrialization.. In the future, in order to further promote the development of the emerging industry of multi-purpose utilization of tobacco, in the scenario of novel tobacco product additives and pharmaceutical use, the extraction of nicotine, cannabinol and aroma-causing components of tobacco is an important research direction; in the scenario of feed application, the cultivation of new varieties of tobacco is an important direction of development; in the scenario of large-scale agricultural application, multi-functional coupling of organic fertilizer based on bio-carbon from tobacco waste resources is an important direction of development. In addition, within the scope of cost permitting, reinforced paper and fiberboard will also be one of the key R&D directions in the future.
Aiming at the key issues of the development and utilization of tobacco biological resources for non-cigarette manufacturing, the current status of foreign technology research and development is sorted out from the aspects of extraction of tobacco active substances and utilization of fiber materials, pointing out that: the active components of tobacco include nicotine, cannabinoid alcohol, polyphenols, proteins, tetraacyl sucrose esters and tobacco tissues (chloroplasts, mitochondria), etc.. Among these, the content and added value of nicotine, chlorogenic acid and cannabinoid alcohol are relatively high, and the extraction technology is more simple. These components have a significant market potential in the fields of pesticides, pharmaceuticals, and tobacco product additives, and have already been widely commercialized abroad. The utilization of fiber materials includes animal feed, fibrous material (paper, fiberboard, particleboard, nitrocellulose), oligosaccharides and biochar fertilizers. The primary directions for large-scale utilization of these materials are the production of biochar-based organic fertilizers, paper, and fiberboard, which are supported by relatively mature technologies. However, the cost associated with these processes remains relatively high, and there have been initial explorations into industrialization.. In the future, in order to further promote the development of the emerging industry of multi-purpose utilization of tobacco, in the scenario of novel tobacco product additives and pharmaceutical use, the extraction of nicotine, cannabinol and aroma-causing components of tobacco is an important research direction; in the scenario of feed application, the cultivation of new varieties of tobacco is an important direction of development; in the scenario of large-scale agricultural application, multi-functional coupling of organic fertilizer based on bio-carbon from tobacco waste resources is an important direction of development. In addition, within the scope of cost permitting, reinforced paper and fiberboard will also be one of the key R&D directions in the future.
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Abstract:
The pea-oat complex protein gel (POPG) was taken as the research object, and the gel strength, water holding capacity (WHC), free sulfhydryl content, disulfide bond content and microstructure were cmeasured to investigate the effects of different enzymes (papain, trypsin, neutral protease, transglutaminase (TG enzyme) and laccase) treatment on the properties of POPG. The ratio of pea protein to oat protein, the mass fraction of complex protein solution and the amount of TG enzyme addition were usel as factors to optimize the formula of POPG by single factor and response surface test. When the addition of TG enzyme was 40 U / g, POPG showed good gel strength (83. 00 g) and WHC (88. 79%). Besides, the above POPG showed lower free sulfhydryl content, higher disulfide bond content, and uniform microstructure. The best formula of complex protein gel was that the ratio of pea protein to oat protein was 1 ∶ 0. 4, the mass fraction of the composite protein solution was 20%, and the TG enzyme addition was 40 U / g. The complex protein gel prepared according to this formula showed a good gel strength (78. 00 g). The POPG prepared in this study holds promise as an animal fat substitnte,offering insights for the processing of green food in the futnre.
The pea-oat complex protein gel (POPG) was taken as the research object, and the gel strength, water holding capacity (WHC), free sulfhydryl content, disulfide bond content and microstructure were cmeasured to investigate the effects of different enzymes (papain, trypsin, neutral protease, transglutaminase (TG enzyme) and laccase) treatment on the properties of POPG. The ratio of pea protein to oat protein, the mass fraction of complex protein solution and the amount of TG enzyme addition were usel as factors to optimize the formula of POPG by single factor and response surface test. When the addition of TG enzyme was 40 U / g, POPG showed good gel strength (83. 00 g) and WHC (88. 79%). Besides, the above POPG showed lower free sulfhydryl content, higher disulfide bond content, and uniform microstructure. The best formula of complex protein gel was that the ratio of pea protein to oat protein was 1 ∶ 0. 4, the mass fraction of the composite protein solution was 20%, and the TG enzyme addition was 40 U / g. The complex protein gel prepared according to this formula showed a good gel strength (78. 00 g). The POPG prepared in this study holds promise as an animal fat substitnte,offering insights for the processing of green food in the futnre.
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Abstract:
To make full use of the discarded tobacco leaves, and produce multiple fine processing products, tobacco extract was obtained from discarded tobacco leaves, and the tobacco extract was finely processed using membrane separation and two-dimensional column chromatography separation techniques. Sensory evaluation screened out characteristic flavor groups with prominent style features, and carried out recombination between characteristic flavor groups. Py-GC-MS was used to analyze the recombinant products. The results showed that the yield of tobacco extract obtained by water extraction was the highest and the overall sensory effect was good; A total of 16 groups were obtained through precision processing, among which the sensory effects of membrane separation of 5nm retention solution and column chromatography separation of A1, C1, and E2 fractions showed distinct characteristics, serving as the characteristic flavor groups of tobacco extracts; Among the recombinant products, products 1 and 2 can enhance the characteristics of tobacco aroma, baking aroma, light aroma, and sweet aroma of cigarettes, and have a good overall sensory effect; The thermal decomposition products of recombinant products 1 and 2 are mainly composed of heterocyclic and aromatic compounds, including sweet, light, nutty and other aroma types. This research provided reference to pluralism products preparation of natural flavors.
To make full use of the discarded tobacco leaves, and produce multiple fine processing products, tobacco extract was obtained from discarded tobacco leaves, and the tobacco extract was finely processed using membrane separation and two-dimensional column chromatography separation techniques. Sensory evaluation screened out characteristic flavor groups with prominent style features, and carried out recombination between characteristic flavor groups. Py-GC-MS was used to analyze the recombinant products. The results showed that the yield of tobacco extract obtained by water extraction was the highest and the overall sensory effect was good; A total of 16 groups were obtained through precision processing, among which the sensory effects of membrane separation of 5nm retention solution and column chromatography separation of A1, C1, and E2 fractions showed distinct characteristics, serving as the characteristic flavor groups of tobacco extracts; Among the recombinant products, products 1 and 2 can enhance the characteristics of tobacco aroma, baking aroma, light aroma, and sweet aroma of cigarettes, and have a good overall sensory effect; The thermal decomposition products of recombinant products 1 and 2 are mainly composed of heterocyclic and aromatic compounds, including sweet, light, nutty and other aroma types. This research provided reference to pluralism products preparation of natural flavors.
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Abstract:
The volatile components of navel oranges were extracted using spinning cone column (SCC) and steam distillation (SD) processes. Qualitative and quantitative analysis of the volatile components were performed by gas chromatography-mass spectrometry (GC-MS). Sensory evaluation combined with multivariate statistical analysis methods were used to identify and determine the main differential volatile components obtained by the two processes. The results demonstrated that the extraction rate of volatile components by the SCC process was markedly higher than that of SD. The volatile components extracted by SCC exhibited stronger fruity, sweet, floral, and green notes, whereas those extracted by SD displayed more pronounced fatty and woody notes. There were notable differences in the types and contents of volatile components extracted by the two methods, and a total of 110 volatile components were extracted, with 97 from the SCC process and 68 from the SD process. Based on a P<0. 05 and a variable importance in projection (VIP) value>1, 33 differential volatile components were screened out. Among them, myrcene, palmitoleic acid, (E)-β-ocimene, and ethyl palmitate were strongly correlated with woody and fatty notes, while (Z)-nerolidol, α-terpineol, D-limonene, and valencene were strongly correlated with fruity, floral, and sweet notes. This indicated that the SCC could efficiently extract these components and retain the fresh and natural aroma of navel orange.
The volatile components of navel oranges were extracted using spinning cone column (SCC) and steam distillation (SD) processes. Qualitative and quantitative analysis of the volatile components were performed by gas chromatography-mass spectrometry (GC-MS). Sensory evaluation combined with multivariate statistical analysis methods were used to identify and determine the main differential volatile components obtained by the two processes. The results demonstrated that the extraction rate of volatile components by the SCC process was markedly higher than that of SD. The volatile components extracted by SCC exhibited stronger fruity, sweet, floral, and green notes, whereas those extracted by SD displayed more pronounced fatty and woody notes. There were notable differences in the types and contents of volatile components extracted by the two methods, and a total of 110 volatile components were extracted, with 97 from the SCC process and 68 from the SD process. Based on a P<0. 05 and a variable importance in projection (VIP) value>1, 33 differential volatile components were screened out. Among them, myrcene, palmitoleic acid, (E)-β-ocimene, and ethyl palmitate were strongly correlated with woody and fatty notes, while (Z)-nerolidol, α-terpineol, D-limonene, and valencene were strongly correlated with fruity, floral, and sweet notes. This indicated that the SCC could efficiently extract these components and retain the fresh and natural aroma of navel orange.
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Abstract:
Using commercially availableHongdeng cherries (nine ripe) as the research object, after three kinds of ozone treatment with low, medium and high mass concentrations, and analysed the changes of physicochemical indexes and ultrastructures during the period of low-temperature storage, explored the effects of ozone treatment on the preservation effect of Hongdeng cherries. The results showed that different mass concentrations of ozone treatment effectively improved the storage quality of Hongdeng cherries, slowed down the increasing trend of decay rate, reduced the accumulation of malondialdehyde (MDA), the accumulation of lipid peroxidation products in cell membranes, slowed down the decline of hardness, and increased the anthocyanin content and antioxidant enzyme activities during the storage period. In particular, compared with the control group, the ozone treatment with medium mass concentration (6. 39 mg / m3) at the end of storage reduced the decay rate by 76. 19 %, increased the hardness by 36. 46 %, maintained the delta E (ΔE) and MDA contents at 69. 45 and 6. 83 μmol /g FW, and promoted the increase of anthocyanin content to 0. 581 ΔOD /g and superoxide dismutase (SOD) activity to 69. 31 U / g. At the same time, it induced the stomatal narrowing of the Hongdeng cherries pericarp, effectively controlled the water loss of the fruit, and maintained the cellular tissue structure by delaying the cell wall degradation, which ultimately achieved the purpose of improving the storage quality of Hongdeng cherries, prolonging the supply period of the market, and improving the economic benefits.
Using commercially availableHongdeng cherries (nine ripe) as the research object, after three kinds of ozone treatment with low, medium and high mass concentrations, and analysed the changes of physicochemical indexes and ultrastructures during the period of low-temperature storage, explored the effects of ozone treatment on the preservation effect of Hongdeng cherries. The results showed that different mass concentrations of ozone treatment effectively improved the storage quality of Hongdeng cherries, slowed down the increasing trend of decay rate, reduced the accumulation of malondialdehyde (MDA), the accumulation of lipid peroxidation products in cell membranes, slowed down the decline of hardness, and increased the anthocyanin content and antioxidant enzyme activities during the storage period. In particular, compared with the control group, the ozone treatment with medium mass concentration (6. 39 mg / m3) at the end of storage reduced the decay rate by 76. 19 %, increased the hardness by 36. 46 %, maintained the delta E (ΔE) and MDA contents at 69. 45 and 6. 83 μmol /g FW, and promoted the increase of anthocyanin content to 0. 581 ΔOD /g and superoxide dismutase (SOD) activity to 69. 31 U / g. At the same time, it induced the stomatal narrowing of the Hongdeng cherries pericarp, effectively controlled the water loss of the fruit, and maintained the cellular tissue structure by delaying the cell wall degradation, which ultimately achieved the purpose of improving the storage quality of Hongdeng cherries, prolonging the supply period of the market, and improving the economic benefits.
, Available online
Abstract:
Grapefruit peel was used as raw material, and carbon quantum dots (G-CQDs) were prepared by hydrothermal method to construct a green and simple fluorescence biosensor for Pb2+ detection in honeysuckle. The morphology, structure and optical properties of G-CODs were characterized by circular dichroism spectroscopy, transmission electron microscopy,ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy. The experimental conditions of the fluorescent biosensor were optimized and its detection performance was analyzed. The results showed that the G-CQDs were spherical and uniformly distributed. The average particle size was 2. 41 nm, and the optimal excitation wavelength was 350 nm. The suitable experimental conditions for the fluorescence biosensor were as follows: Hemin concentration of 60 μmol / L, reaction time of 30 min, reaction temperature of 25℃, K+ concentration of 10 mmol / L and pH value of 6. 5. Compared with other metal ions (Ag+, Zn2+, Cd2+, Cu2+ and Hg2+), the fluorescence biosensor had higher selectivity for Pb2+, and its fluorescence intensity increased with the increase of Pb2+ mass concentration. In the linear range of 0. 1 ~ 5. 0 μg / mL, the linear relationship between the two was good, R2 was 0. 998 0, and the detection limit was 0. 063 9 μg / mL. Compared with the conventional method (ICP-MS method), the fluorescence biosensor had good accuracy, and had the advantages of green environmental protection, economical and effective, simple operation and so on.
Grapefruit peel was used as raw material, and carbon quantum dots (G-CQDs) were prepared by hydrothermal method to construct a green and simple fluorescence biosensor for Pb2+ detection in honeysuckle. The morphology, structure and optical properties of G-CODs were characterized by circular dichroism spectroscopy, transmission electron microscopy,ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy. The experimental conditions of the fluorescent biosensor were optimized and its detection performance was analyzed. The results showed that the G-CQDs were spherical and uniformly distributed. The average particle size was 2. 41 nm, and the optimal excitation wavelength was 350 nm. The suitable experimental conditions for the fluorescence biosensor were as follows: Hemin concentration of 60 μmol / L, reaction time of 30 min, reaction temperature of 25℃, K+ concentration of 10 mmol / L and pH value of 6. 5. Compared with other metal ions (Ag+, Zn2+, Cd2+, Cu2+ and Hg2+), the fluorescence biosensor had higher selectivity for Pb2+, and its fluorescence intensity increased with the increase of Pb2+ mass concentration. In the linear range of 0. 1 ~ 5. 0 μg / mL, the linear relationship between the two was good, R2 was 0. 998 0, and the detection limit was 0. 063 9 μg / mL. Compared with the conventional method (ICP-MS method), the fluorescence biosensor had good accuracy, and had the advantages of green environmental protection, economical and effective, simple operation and so on.
, Available online
Abstract:
Electronic nose and head space-solid phase microextraction-gas chromatography mass spectrometry (HSSPME-GC-MS) combined with the odor activity values (OAV) and orthogonal partial least squares discriminant analysis (OPLS-DA) modelwere used to study the effects of Lactobacillus plantarum CICC 20022 fermentation on volatile aroma compounds in jujube juice. The results showed that fermented jujube juice contained more terpenes, sulfur compounds, aromatic compounds and organosulfur than unfermented jujube juice, and these compounds contribute the juice with more intense floral and fruity aroma. There had 48 and 42 volatile aroma compounds were identified with the total mass concentrations of 4 479. 54 μg / L and 6 943. 14 μg / L for unfermented and fermented jujube juice, respectively. The mass concentration of acid compounds in fermented jujube juice increased significantly, with decanoic acid increasing by 193. 68%, while the types of ester compounds were significantly decreased, and the isopropyl palmitate, citral and nerolidol acetone with floral and fruity aromas were newly formed in fermented jujube juice. The floral flavour of damasone has outstanding contribution to the fragrance of fermented jujube juice. The seven main different volatile aroma components were benzaldehyde, capric acid, benzyl alcohol, nonanoic acid, damastone, lauric acid and caproic acid. Therefore, fermentation with L. plantarum could enhance the overall flavor of jujube juice and give it a floral and fruity aroma.
Electronic nose and head space-solid phase microextraction-gas chromatography mass spectrometry (HSSPME-GC-MS) combined with the odor activity values (OAV) and orthogonal partial least squares discriminant analysis (OPLS-DA) modelwere used to study the effects of Lactobacillus plantarum CICC 20022 fermentation on volatile aroma compounds in jujube juice. The results showed that fermented jujube juice contained more terpenes, sulfur compounds, aromatic compounds and organosulfur than unfermented jujube juice, and these compounds contribute the juice with more intense floral and fruity aroma. There had 48 and 42 volatile aroma compounds were identified with the total mass concentrations of 4 479. 54 μg / L and 6 943. 14 μg / L for unfermented and fermented jujube juice, respectively. The mass concentration of acid compounds in fermented jujube juice increased significantly, with decanoic acid increasing by 193. 68%, while the types of ester compounds were significantly decreased, and the isopropyl palmitate, citral and nerolidol acetone with floral and fruity aromas were newly formed in fermented jujube juice. The floral flavour of damasone has outstanding contribution to the fragrance of fermented jujube juice. The seven main different volatile aroma components were benzaldehyde, capric acid, benzyl alcohol, nonanoic acid, damastone, lauric acid and caproic acid. Therefore, fermentation with L. plantarum could enhance the overall flavor of jujube juice and give it a floral and fruity aroma.
, Available online
Abstract:
To develop apricot pomace flavoring, the most effective aroma-producing strain was isolated and screened from apricot orchard soil. The process conditions for microbial fermentation of apricot pomace by this strain were optimized using single-factor experiments and Box-Behnken response surface methodology, and the key enzyme was preliminarily identified. The results showed that the strain LY13, identified as Wickerhamomyces, had the best aroma-producing effect. After fermentation of apricot pomace by this strain, the resulting product exhibited rich sweet, fruity, and floral aromas, with a high total content of alcohols, esters, and ketones in the fermentation liquid. The optimal fermentation conditions were a stirring speed of 145 r / min, a fermentation time of 49 hours, a fermentation temperature of 31℃, and an initial pH of 7. 1. Under these conditions, the total content of volatile aromatic compounds in the fermented product reached 135. 38 μg / g, and the key enzyme responsible for aroma production was mainly located in the cell membrane. This study provides a novel strain resource for aroma-producing microorganisms and a theoretical basis for the industrial production of apricot pomace flavoring through microbial fermentation.
To develop apricot pomace flavoring, the most effective aroma-producing strain was isolated and screened from apricot orchard soil. The process conditions for microbial fermentation of apricot pomace by this strain were optimized using single-factor experiments and Box-Behnken response surface methodology, and the key enzyme was preliminarily identified. The results showed that the strain LY13, identified as Wickerhamomyces, had the best aroma-producing effect. After fermentation of apricot pomace by this strain, the resulting product exhibited rich sweet, fruity, and floral aromas, with a high total content of alcohols, esters, and ketones in the fermentation liquid. The optimal fermentation conditions were a stirring speed of 145 r / min, a fermentation time of 49 hours, a fermentation temperature of 31℃, and an initial pH of 7. 1. Under these conditions, the total content of volatile aromatic compounds in the fermented product reached 135. 38 μg / g, and the key enzyme responsible for aroma production was mainly located in the cell membrane. This study provides a novel strain resource for aroma-producing microorganisms and a theoretical basis for the industrial production of apricot pomace flavoring through microbial fermentation.
Journal Information
Founded in 1986， bimonthly
Administered by：The Education Department Henan Province
Sponsored by：Zhengzhou University of Light Industry
Editor-in-chief：Wei Shizhong
Executive Editor-in-Chief：Zou Lin
Deputy Editor-in-Chief：Qu Shuanghong
Edited & published by：Editorial Department of Journal of Light Industry
CN 41-1437/TS
ISSN 2096-1553
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