2022 Vol. 37, No. 1
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2022, 37(1)
:1-11.
doi: 10.12187/2022.01.001
Abstract:
In this study, the metatranscriptome technology was used to study the differences in the composition and genes functions of the physiologically active bacterial and fungal communities in the strong-flavor Baijiu fermented grains (FGs) at different spatial locations of pit. The results showed that 87 phyla, 78 classes, 165 orders, 396 families, 1612 genera and 7234 species were detected in the bacterial community, and 8 phyla, 26 classes, 58 orders, 127 families, 223 genera and 394 species were detected in the fungal community. However, there was little difference in the number of active microorganisms among the top, middle and bottom layers of FGs. There was no significant difference in the bacterial and fungal community composition in each layer of FGs, with Firmicutes and Ascomycota as the main dominant bacterial and fungal phylum, respectively. Bacillus and Saccharomyces were the main dominant bacterial and fungal class, respectively. Lactobacillus was the main dominant bacterial genera, Saccharomyces (top and bottom) or Scheffersomyces (middle) was the main dominant fungal genera. Furthermore, the number of differentially-expressed genes between the bottom and middle layer, and between the middle and upper layer of FGs was higher and it was 90 and 67 respectively. And the differentially-expressed genes were mainly concentrated in RNA degradation and Glycolysis/Gluconeogenesis pathway, and most of the difference gene function between each layer was metabolism. The active microbial flora in the middle FGs had the lowest effect on RNA degradation, and the active microbial flora in the bottom FGs contributed the most to the metabolic activity.
In this study, the metatranscriptome technology was used to study the differences in the composition and genes functions of the physiologically active bacterial and fungal communities in the strong-flavor Baijiu fermented grains (FGs) at different spatial locations of pit. The results showed that 87 phyla, 78 classes, 165 orders, 396 families, 1612 genera and 7234 species were detected in the bacterial community, and 8 phyla, 26 classes, 58 orders, 127 families, 223 genera and 394 species were detected in the fungal community. However, there was little difference in the number of active microorganisms among the top, middle and bottom layers of FGs. There was no significant difference in the bacterial and fungal community composition in each layer of FGs, with Firmicutes and Ascomycota as the main dominant bacterial and fungal phylum, respectively. Bacillus and Saccharomyces were the main dominant bacterial and fungal class, respectively. Lactobacillus was the main dominant bacterial genera, Saccharomyces (top and bottom) or Scheffersomyces (middle) was the main dominant fungal genera. Furthermore, the number of differentially-expressed genes between the bottom and middle layer, and between the middle and upper layer of FGs was higher and it was 90 and 67 respectively. And the differentially-expressed genes were mainly concentrated in RNA degradation and Glycolysis/Gluconeogenesis pathway, and most of the difference gene function between each layer was metabolism. The active microbial flora in the middle FGs had the lowest effect on RNA degradation, and the active microbial flora in the bottom FGs contributed the most to the metabolic activity.
2022, 37(1)
:12-19.
doi: 10.12187/2022.01.002
Abstract:
Multiple PCR detection techniques were established for 6 foodborne pathogenic bacteria specific genes (the nuc gene of Staphylococcus aureus, tdh gene of Vibrio parahaemolyticus, hly gene of Listeria monocytogenes, ompA gene of Cronobacter sakazakii, invA gene of Salmonella typhimurium, and rfbE gene of Escherichia coli O157:H7). The sensitivity and specificity of multiplex PCR were analyzed, and its application feasibility in artificially-contaminated milk was also evaluated. The results showed that the specific PCR products of 345 bp, 307 bp, 269 bp, 237 bp, 188 bp and 142 bp were amplified as expected in multiplex PCR without nonspecific amplification and cross reactivity with non-target pathogenic bacteria. Multiplex PCR developed in this study could detect as little as 10 pg of genomic DNA of pure bacterial culture and 103 CFU/mL of milk artificially-contaminated with pathogenic bacteria, which could specifically, sensitively, rapidly and efficiently detect six foodborne pathogenic bacteria simultaneously.
Multiple PCR detection techniques were established for 6 foodborne pathogenic bacteria specific genes (the nuc gene of Staphylococcus aureus, tdh gene of Vibrio parahaemolyticus, hly gene of Listeria monocytogenes, ompA gene of Cronobacter sakazakii, invA gene of Salmonella typhimurium, and rfbE gene of Escherichia coli O157:H7). The sensitivity and specificity of multiplex PCR were analyzed, and its application feasibility in artificially-contaminated milk was also evaluated. The results showed that the specific PCR products of 345 bp, 307 bp, 269 bp, 237 bp, 188 bp and 142 bp were amplified as expected in multiplex PCR without nonspecific amplification and cross reactivity with non-target pathogenic bacteria. Multiplex PCR developed in this study could detect as little as 10 pg of genomic DNA of pure bacterial culture and 103 CFU/mL of milk artificially-contaminated with pathogenic bacteria, which could specifically, sensitively, rapidly and efficiently detect six foodborne pathogenic bacteria simultaneously.
2022, 37(1)
:20-25.
doi: 10.12187/2022.01.003
Abstract:
The liquid-state fermentation medium conditions of Trichoderma reesei of high yield cellulase were optimized with natural agricultural products as the main raw materials by different test design methods, such as the Plackett-Burman (PB), steepest climbing, Box-Behnken (BB) and response surface method (RSM) analysis. The results showed that the optimal fermentation medium conditions for enzyme production were soybean meal 2.140%, wheat bran 1.88%, peptone 0.30%. Under these conditions, the cellulase activity of the fermentation broth could reach (42.62±1.30) U/mL. In the later stage of fermentation (5 d), with the large growth of mycelium, the cellulase activity increased continuously. The crude enzyme solution could degrade cellulose and hemicellulose in corn straw to produce fermentable sugars such as free glucose, xylose, arabinose and cellobiose.
The liquid-state fermentation medium conditions of Trichoderma reesei of high yield cellulase were optimized with natural agricultural products as the main raw materials by different test design methods, such as the Plackett-Burman (PB), steepest climbing, Box-Behnken (BB) and response surface method (RSM) analysis. The results showed that the optimal fermentation medium conditions for enzyme production were soybean meal 2.140%, wheat bran 1.88%, peptone 0.30%. Under these conditions, the cellulase activity of the fermentation broth could reach (42.62±1.30) U/mL. In the later stage of fermentation (5 d), with the large growth of mycelium, the cellulase activity increased continuously. The crude enzyme solution could degrade cellulose and hemicellulose in corn straw to produce fermentable sugars such as free glucose, xylose, arabinose and cellobiose.
2022, 37(1)
:26-32.
doi: 10.12187/2022.01.004
Abstract:
As an anionic polyelectrolyte, the behavior of sodium alginate solution was easy to be affected by electrolyte. The interaction between non-ionic surfactant Tween 20 and sodium alginate and the effect of NaCl on the interaction were studied by surface tension, fluorescence spectrum and viscosity measurements. The results showed that the surface tension of Tween 20-sodium alginate complexes was higher than that without sodium alginate before cmc. The higher the mass fraction of sodium alginate, the higher the surface tension. The surface tension of Tween 20-sodium alginate-NaCl complexes decreased in the presence of NaCl. The I1/I3 of Tween 20-sodium alginate complexes decreased when the concentration of sodium alginate increased. Before cpc, I1/I3 of Tween 20-sodium alginate-NaCl complexes increased in the presence of NaCl. When the concentration of Tween 20 was higher than cmc*, the viscosity of Tween 20-sodium alginate complexes decreased slightly. The viscosity of Tween 20-alginate complexes increased slightly in the presence of NaCl when Tween 20 reached a certain concentration.
As an anionic polyelectrolyte, the behavior of sodium alginate solution was easy to be affected by electrolyte. The interaction between non-ionic surfactant Tween 20 and sodium alginate and the effect of NaCl on the interaction were studied by surface tension, fluorescence spectrum and viscosity measurements. The results showed that the surface tension of Tween 20-sodium alginate complexes was higher than that without sodium alginate before cmc. The higher the mass fraction of sodium alginate, the higher the surface tension. The surface tension of Tween 20-sodium alginate-NaCl complexes decreased in the presence of NaCl. The I1/I3 of Tween 20-sodium alginate complexes decreased when the concentration of sodium alginate increased. Before cpc, I1/I3 of Tween 20-sodium alginate-NaCl complexes increased in the presence of NaCl. When the concentration of Tween 20 was higher than cmc*, the viscosity of Tween 20-sodium alginate complexes decreased slightly. The viscosity of Tween 20-alginate complexes increased slightly in the presence of NaCl when Tween 20 reached a certain concentration.
2022, 37(1)
:33-39.
doi: 10.12187/2022.01.005
Abstract:
Taiping Houkui from core and non-core producing areas was taken as the research object. The HPLC fingerprints of Taiping Houkui was established by optimizing high performance liquid chromatography (HPLC) detection methods, and the multivariate statistical methods were used to analyze Taiping Houkui from different producing areas. The results showed that according to the optimized HPLC detection method, the 10 kinds of Taiping Houkui samples from the core producing area were quantitatively analyzed, and 11 common peaks(GA、5-GC、GC、TB、EGC、Cat、EC、Caf、EGCG、GCG、ECG) were identified and well separated, and the similarity of 10 Taiping Houkui samples was above 0.982. Taiping Houkui samples from core and non-core producing areas were clustered together according to the origin in the PCA score chart. The 6 biomarkers (EC, GC, Cat, TB, EGC, Caf) screened out were characteristic components that could distinguish whether Taiping Houkui came from the core producing area.
Taiping Houkui from core and non-core producing areas was taken as the research object. The HPLC fingerprints of Taiping Houkui was established by optimizing high performance liquid chromatography (HPLC) detection methods, and the multivariate statistical methods were used to analyze Taiping Houkui from different producing areas. The results showed that according to the optimized HPLC detection method, the 10 kinds of Taiping Houkui samples from the core producing area were quantitatively analyzed, and 11 common peaks(GA、5-GC、GC、TB、EGC、Cat、EC、Caf、EGCG、GCG、ECG) were identified and well separated, and the similarity of 10 Taiping Houkui samples was above 0.982. Taiping Houkui samples from core and non-core producing areas were clustered together according to the origin in the PCA score chart. The 6 biomarkers (EC, GC, Cat, TB, EGC, Caf) screened out were characteristic components that could distinguish whether Taiping Houkui came from the core producing area.
2022, 37(1)
:40-45.
doi: 10.12187/2022.01.006
Abstract:
In order to screen out the appropriate sterilization method for sun-dried green tea, six sterilization methods including irradiation sterilization, ultraviolet sterilization, microwave sterilization, high-pressure steam sterilization, pasteurization and ozone sterilization were used to treat sun-dried green tea, then total viable counts, biochemical composition and sensory evaluation of sun-dried green tea after sterilization were determined. The results showed that microorganisms in tea leaves were sterilized fully by methods of high-pressure steam sterilization and irradiation sterilization, 7.5 kGy irradiation sterilization had the least effect on the biochemical compositions of tea, only the contents of soluble sugar, catechin, flagellin, rutin and luteolin changing significantly (P<0.05). Meanwhile, sensory evaluation also confirmed that 7.5 kGy irradiation sterilization had the least effect on sensory quality of sun-dried green tea. In conclusion, the best sterilization method of sun-dried green tea was 7.5 kGy irradiation sterilization.
In order to screen out the appropriate sterilization method for sun-dried green tea, six sterilization methods including irradiation sterilization, ultraviolet sterilization, microwave sterilization, high-pressure steam sterilization, pasteurization and ozone sterilization were used to treat sun-dried green tea, then total viable counts, biochemical composition and sensory evaluation of sun-dried green tea after sterilization were determined. The results showed that microorganisms in tea leaves were sterilized fully by methods of high-pressure steam sterilization and irradiation sterilization, 7.5 kGy irradiation sterilization had the least effect on the biochemical compositions of tea, only the contents of soluble sugar, catechin, flagellin, rutin and luteolin changing significantly (P<0.05). Meanwhile, sensory evaluation also confirmed that 7.5 kGy irradiation sterilization had the least effect on sensory quality of sun-dried green tea. In conclusion, the best sterilization method of sun-dried green tea was 7.5 kGy irradiation sterilization.
2022, 37(1)
:46-54.
doi: 10.12187/2022.01.007
Abstract:
Food is easily contaminated by microorganism during production and consumption,which causes serious adverse effect on its safety and quality.As an alternative source of traditional ultraviolet mercury lamp,ultraviolet light-emitting diodes (UV-LEDs) have many advantages, such as adjustable wavelength, environmentally friendly, safe and efficient.This paper aimed to review the application of UV-LEDs in the field of food sterilization and preservation,its influence on food quality and its application progress in collaboration with other non-thermal sterilization technologies.The results indicated that UV-LEDS could not only effectively sterilize foodborne pathogenic bacteria and spoilage bacteria,but also could well maintain the quality of food products.The bactericidal effect could be further enhanced when it is used in combination with other technologies such as slightly acidic electrolytic water,Cl2 and ultrasound. However,UV-LEDs have some disadvantages,such as weak penetration and small processing capacity.More attention should be paid to the optimization of processing parameters and equipment development in the future.This paper provides reference for the practical application of UV-LEDs in the field of food safety control.
Food is easily contaminated by microorganism during production and consumption,which causes serious adverse effect on its safety and quality.As an alternative source of traditional ultraviolet mercury lamp,ultraviolet light-emitting diodes (UV-LEDs) have many advantages, such as adjustable wavelength, environmentally friendly, safe and efficient.This paper aimed to review the application of UV-LEDs in the field of food sterilization and preservation,its influence on food quality and its application progress in collaboration with other non-thermal sterilization technologies.The results indicated that UV-LEDS could not only effectively sterilize foodborne pathogenic bacteria and spoilage bacteria,but also could well maintain the quality of food products.The bactericidal effect could be further enhanced when it is used in combination with other technologies such as slightly acidic electrolytic water,Cl2 and ultrasound. However,UV-LEDs have some disadvantages,such as weak penetration and small processing capacity.More attention should be paid to the optimization of processing parameters and equipment development in the future.This paper provides reference for the practical application of UV-LEDs in the field of food safety control.
2022, 37(1)
:55-61.
doi: 10.12187/2022.01.008
Abstract:
In order to investigate the heat release law and difference of tobacco slices in heated tobacco product prepared by different processes, the thermal weight loss behavior in different atmospheres of three kinds of tobacco slices in heated tobacco product prepared by thick pulp method, papermaking powder spraying method and paper making method were studied by thermogravimetric analysis.The results showed that:the thermal weight loss behavior of the three kinds of tobacco slices were the same. They all experienced multiple weight loss stages such as water distillation, material volatilization and cracking in air and nitrogen atmosphere. When the heating temperature reached 370℃, the effective release of tobacco slice components could be realized. The influence of the different atmosphere on the thermogravimetric process of the tobacco slice samples mainly occurred in the heating temperature range of 240~400℃. Air atmosphere increased the thermal weight loss rate of tobacco slices, promoted the weight loss temperature at each stage to the direction of low temperature, and was conducive to reduce the difficulty of thermal volatilization and thermal oxidation degradation of glycerol, cellulose and other substances. The structure looseness and material composition of tobacco slices prepared by different processes were different, resulting in differences in weight loss temperature region, maximum weight loss rate temperature and mass loss during heating process. Loose tissue structure and high exogenous components could accelerate the rate of thermal weight loss and increase the mass loss of samples.
In order to investigate the heat release law and difference of tobacco slices in heated tobacco product prepared by different processes, the thermal weight loss behavior in different atmospheres of three kinds of tobacco slices in heated tobacco product prepared by thick pulp method, papermaking powder spraying method and paper making method were studied by thermogravimetric analysis.The results showed that:the thermal weight loss behavior of the three kinds of tobacco slices were the same. They all experienced multiple weight loss stages such as water distillation, material volatilization and cracking in air and nitrogen atmosphere. When the heating temperature reached 370℃, the effective release of tobacco slice components could be realized. The influence of the different atmosphere on the thermogravimetric process of the tobacco slice samples mainly occurred in the heating temperature range of 240~400℃. Air atmosphere increased the thermal weight loss rate of tobacco slices, promoted the weight loss temperature at each stage to the direction of low temperature, and was conducive to reduce the difficulty of thermal volatilization and thermal oxidation degradation of glycerol, cellulose and other substances. The structure looseness and material composition of tobacco slices prepared by different processes were different, resulting in differences in weight loss temperature region, maximum weight loss rate temperature and mass loss during heating process. Loose tissue structure and high exogenous components could accelerate the rate of thermal weight loss and increase the mass loss of samples.
2022, 37(1)
:62-67.
doi: 10.12187/2022.01.009
Abstract:
Neutral protease, pectinase and amylase were used to treat the tobacco flake concentrate from Guizhou raw materials and the effects of different enzyme treatments on the conventional chemical components and fragrance components in the concentrate of the treated samples were analyzed. The concentrated solution after enzyme treatment was coated on the tobacco sheet substrate and the sensory quality of tobacco sheet was evaluated. The results showed that the mass fractions of protein, reducing sugars, total sugars and amino acids in the concentrated solution treated with neutral protease were greatly reduced; 10 new fragrance ingredients including 4-cyclopentene-1,3-dione and β-ionone were found in the concentrated treated solution. The total content of aroma components in the concentrate had been increased from 0.907 mg/mL to 2.844 mg/mL, with an increase of 213.56%. There was no significant change in the conventional chemical components and flavor components in the concentrates treated with pectinase and amylase. Tobacco flakes coated with the concentrated solution treated with neutral protease were better than amylase group, pectinase group and blank group in terms of aroma, harmony, irritation and aftertaste.
Neutral protease, pectinase and amylase were used to treat the tobacco flake concentrate from Guizhou raw materials and the effects of different enzyme treatments on the conventional chemical components and fragrance components in the concentrate of the treated samples were analyzed. The concentrated solution after enzyme treatment was coated on the tobacco sheet substrate and the sensory quality of tobacco sheet was evaluated. The results showed that the mass fractions of protein, reducing sugars, total sugars and amino acids in the concentrated solution treated with neutral protease were greatly reduced; 10 new fragrance ingredients including 4-cyclopentene-1,3-dione and β-ionone were found in the concentrated treated solution. The total content of aroma components in the concentrate had been increased from 0.907 mg/mL to 2.844 mg/mL, with an increase of 213.56%. There was no significant change in the conventional chemical components and flavor components in the concentrates treated with pectinase and amylase. Tobacco flakes coated with the concentrated solution treated with neutral protease were better than amylase group, pectinase group and blank group in terms of aroma, harmony, irritation and aftertaste.
2022, 37(1)
:68-78.
doi: 10.12187/2022.01.010
Abstract:
The tobacco 202 was used as experimental material in this study. CDS region of C4H2 gene was cloned from young leaves of tobacco. To investigate the variation trend of flavonoid content in leaves and the expression characteristics in different tissues, the gene was analyzed by the bioinformatics, the prokaryotic expression vector was constructed, and the recombinant plasmid was induced and purified in E. coli. The results showed that NtC4H2 gene was a member of cytochrome P450 superfamily. There was a transmembrane region, which was unstable hydrophilic protein, with high secondary structure of helix and irregular coil. The recombinant proteins NtC4H2 mainly existed as insoluble inclusion body protein in expressing bacteria. The expression levels of NtC4H2 gene expression in different tobacco tissues were lower leavesNtC4H2 gene in the upper leaves fluctuated significantly within the different sampling time, and reached the peak at 48h. The expression pattern was positively correlated with the accumulation of flavonoids in the leaves.
The tobacco 202 was used as experimental material in this study. CDS region of C4H2 gene was cloned from young leaves of tobacco. To investigate the variation trend of flavonoid content in leaves and the expression characteristics in different tissues, the gene was analyzed by the bioinformatics, the prokaryotic expression vector was constructed, and the recombinant plasmid was induced and purified in E. coli. The results showed that NtC4H2 gene was a member of cytochrome P450 superfamily. There was a transmembrane region, which was unstable hydrophilic protein, with high secondary structure of helix and irregular coil. The recombinant proteins NtC4H2 mainly existed as insoluble inclusion body protein in expressing bacteria. The expression levels of NtC4H2 gene expression in different tobacco tissues were lower leaves
2022, 37(1)
:79-86.
doi: 10.12187/2022.01.011
Abstract:
In order to reveal the style characteristics differences of intermediate flavor flue-cured tobacco leaves, the release of 96 aroma components in mainstream smoke of three intermediate flavor tobacco leaves (Chongqing C3F, Zunyi C3F and Mudanjiang C3F) was determined by GC-MS. Then the activity values of 96 aroma components were calculated, and the activity values of 10 aroma notes were also obtained. By comparing the activity values of 10 aroma notes, the aroma note style characteristics differences of three intermediate flavor flue-cured tobacco leaves were distinguished. The results were as follows:In the mainstream smoke of the three intermediate flavor flue-cured tobacco leaves, the total release was 1 255.251 μg/g, 856.274 μg/g and 967.670 μg/g respectively. Acetic acid had the highest release, followed by hexadecanoic acid and oleic acid; Among the 10 aroma notes, the acid note and the fat-waxy note had the highest release. The main note of the three intermediate flavor tobacco leaves was the nutty note and the sweet note, followed by the fresh note and roasted-sweet note; Among the three intermediate flavor flue-cured tobacco leaves, the balsamic note was most outstanding in Chongqing C3F, as the fresh and fruity note in Zunyi C3F and the sweet and nutty note in Mudanjiang C3F.
In order to reveal the style characteristics differences of intermediate flavor flue-cured tobacco leaves, the release of 96 aroma components in mainstream smoke of three intermediate flavor tobacco leaves (Chongqing C3F, Zunyi C3F and Mudanjiang C3F) was determined by GC-MS. Then the activity values of 96 aroma components were calculated, and the activity values of 10 aroma notes were also obtained. By comparing the activity values of 10 aroma notes, the aroma note style characteristics differences of three intermediate flavor flue-cured tobacco leaves were distinguished. The results were as follows:In the mainstream smoke of the three intermediate flavor flue-cured tobacco leaves, the total release was 1 255.251 μg/g, 856.274 μg/g and 967.670 μg/g respectively. Acetic acid had the highest release, followed by hexadecanoic acid and oleic acid; Among the 10 aroma notes, the acid note and the fat-waxy note had the highest release. The main note of the three intermediate flavor tobacco leaves was the nutty note and the sweet note, followed by the fresh note and roasted-sweet note; Among the three intermediate flavor flue-cured tobacco leaves, the balsamic note was most outstanding in Chongqing C3F, as the fresh and fruity note in Zunyi C3F and the sweet and nutty note in Mudanjiang C3F.
2022, 37(1)
:87-94.
doi: 10.12187/2022.01.012
Abstract:
13 kinds of alcohol flavors were added to cigarette filter rods, the extraction conditions of flavors in cigarettes were optimized, the GC-MS analysis method of alcohol homologous compounds was established, and the transfer behavior of alcohol flavors in cigarettes during storage and smoking was studied. The results showed that:when the extraction solvent was absolute ethanol, the extraction method was ultrasonic vibration, the extraction solvent volume was 6 mL, the extraction time was 20 minutes, the extraction amount of alcohol flavors was the highest. The linearity of 13 alcohol flavors was good in the concentration range of 0.63~10.00 μg/mL, and the precision and recovery rate were high. During storage period, the filter retention rate of 13 alcohol flavors was 9.68%~52.03%, the migration rate of tobacco was 1.06%~17.36%, and the loss rate was 36.88%~87.01%; during smoking, the mainstream smoke transfer rate of 13 alcohol flavors was 0~14.49%, the filter residue rate was 14.78%~73.25%. The filter retention rate and the smoke transfer rate of pentadecanol were relatively high high, the tobacco migration rate, the loss rate, and the filter residue rate were relatively low, so it was suitable for being used in the filter-flavored cigarettes. The transfer behavior of alcohol flavors that were cis and trans isomers were similar during storagin and smoking; alcohol flavors that were homologous to each other had similar transfer behaviors. In summary, with the molecular weight and boiling point increasing, the filter retention rate, flue gas transfer rate, and filter residue rate gradually increased, while the loss rate gradually decreased.
13 kinds of alcohol flavors were added to cigarette filter rods, the extraction conditions of flavors in cigarettes were optimized, the GC-MS analysis method of alcohol homologous compounds was established, and the transfer behavior of alcohol flavors in cigarettes during storage and smoking was studied. The results showed that:when the extraction solvent was absolute ethanol, the extraction method was ultrasonic vibration, the extraction solvent volume was 6 mL, the extraction time was 20 minutes, the extraction amount of alcohol flavors was the highest. The linearity of 13 alcohol flavors was good in the concentration range of 0.63~10.00 μg/mL, and the precision and recovery rate were high. During storage period, the filter retention rate of 13 alcohol flavors was 9.68%~52.03%, the migration rate of tobacco was 1.06%~17.36%, and the loss rate was 36.88%~87.01%; during smoking, the mainstream smoke transfer rate of 13 alcohol flavors was 0~14.49%, the filter residue rate was 14.78%~73.25%. The filter retention rate and the smoke transfer rate of pentadecanol were relatively high high, the tobacco migration rate, the loss rate, and the filter residue rate were relatively low, so it was suitable for being used in the filter-flavored cigarettes. The transfer behavior of alcohol flavors that were cis and trans isomers were similar during storagin and smoking; alcohol flavors that were homologous to each other had similar transfer behaviors. In summary, with the molecular weight and boiling point increasing, the filter retention rate, flue gas transfer rate, and filter residue rate gradually increased, while the loss rate gradually decreased.
2022, 37(1)
:95-102,117.
doi: 10.12187/2022.01.013
Abstract:
In order to clarify the sensory contribution characteristics of different acid flavors in cigarettes, pre-column silanization-gas chromatography-mass spectrometry technology was used to analyze the particulate phase transfer ratios of mainstream cigarette smoke of three organic acids(valeric acid, caprylic acid and capric acid) with different flavoring methods and different circumferences. Combined with the olfactory threshold/taste threshold olfactory contribution and taste contribution were defined and calcuated. The results showed that in terms of the particulate phase transfer ratios of mainstream cigarette smoke, volatile organic acids (valeric acid) were more suitable to be added by breakable filter capsules, and semi volatile organic acids (octanoic acid and decanoic acid) were more suitable to be added by cut tobacco. Under different flavoring methods, the transfer ratios of volatile organic acids was the highest in thin cigarettes, while the transfer ratios of semi volatile organic acids increased with the increase of the circumference of the cigarette when adding flavor in breakable filter capsules. In cigarettes with different flavoring methods and different circumferences, caprylic acid had the best olfactory contribution, and valeric acid had the best taste contribution. The sensory contribution of the 3 acids was mainly olfactory effect.
In order to clarify the sensory contribution characteristics of different acid flavors in cigarettes, pre-column silanization-gas chromatography-mass spectrometry technology was used to analyze the particulate phase transfer ratios of mainstream cigarette smoke of three organic acids(valeric acid, caprylic acid and capric acid) with different flavoring methods and different circumferences. Combined with the olfactory threshold/taste threshold olfactory contribution and taste contribution were defined and calcuated. The results showed that in terms of the particulate phase transfer ratios of mainstream cigarette smoke, volatile organic acids (valeric acid) were more suitable to be added by breakable filter capsules, and semi volatile organic acids (octanoic acid and decanoic acid) were more suitable to be added by cut tobacco. Under different flavoring methods, the transfer ratios of volatile organic acids was the highest in thin cigarettes, while the transfer ratios of semi volatile organic acids increased with the increase of the circumference of the cigarette when adding flavor in breakable filter capsules. In cigarettes with different flavoring methods and different circumferences, caprylic acid had the best olfactory contribution, and valeric acid had the best taste contribution. The sensory contribution of the 3 acids was mainly olfactory effect.
2022, 37(1)
:103-109.
doi: 10.12187/2022.01.014
Abstract:
Based on independently-developed vacuum ultraviolet single photon ionization time-of-flight mass spectrometer (SPI-MS), a system was developed for the rapid detection of volatile organic compounds (VOCs) in water with direct injection. The results showed that the linearity was good in the range of 5~40 μg/L for benzene, toluene, xylene and chlorobenzene, and the detection limits were 0.311 9 μg/L, 0.713 3 μg/L 0.056 0 μg/L and 0.169 7 μg/L respectively,which met the requirements of the Environmental Quality Standard for Surface Water (GB 3838-2002) for the rapid detection of these four substances. The instrument was applied to the online detection of VOCs in a water area in North China, and a total of 13 VOCs substances were detected. With a large monitoring range and rapid response, the ship-mounted SPI-MS could respond to the distribution and characteristics of VOCs pollution in water in a timely manner, and had broad development potential in the continuous on-line monitoring of VOCs in water.
Based on independently-developed vacuum ultraviolet single photon ionization time-of-flight mass spectrometer (SPI-MS), a system was developed for the rapid detection of volatile organic compounds (VOCs) in water with direct injection. The results showed that the linearity was good in the range of 5~40 μg/L for benzene, toluene, xylene and chlorobenzene, and the detection limits were 0.311 9 μg/L, 0.713 3 μg/L 0.056 0 μg/L and 0.169 7 μg/L respectively,which met the requirements of the Environmental Quality Standard for Surface Water (GB 3838-2002) for the rapid detection of these four substances. The instrument was applied to the online detection of VOCs in a water area in North China, and a total of 13 VOCs substances were detected. With a large monitoring range and rapid response, the ship-mounted SPI-MS could respond to the distribution and characteristics of VOCs pollution in water in a timely manner, and had broad development potential in the continuous on-line monitoring of VOCs in water.
2022, 37(1)
:110-117.
doi: 10.12187/2022.01.015
Abstract:
The waste activated sludge with low concentration and low organic matter was fermented under different conditions including natural, nanoscale zero-valent iron (nZVI), 2KHSO5·KHSO4·K2SO4(PMS), K2SO4, nZVI+PMS and nZVI+K2SO4. The soluble protein, polysaccharide, short volatile fatty acids (SCFAs) and biological enzyme were analyzed during the fermentation process, and the effects of nZVI on hydrolytic acidification performance of the excess sludge were studied. The results showed that hydrolytic acidification performance of the nZVI+PMS fermentation system was optimal, and the mass concentration of protein, polysaccharide and SCFAs was 255.07 mg/L, 138.31 mg/L and 356.8 mg/L respectively. The maximal activity of protease and α-glucosidase appeared in the nZVI+PMS fermentation system, however the maximal activity of alkaline phosphatase and acid phosphatase appeared in the nZVI fermentation system. In addition, the bioenzyme activity of the K2SO4 fermentation system was similar to that of natural fermentation system. These results indicated that nZVI could improve effectively the fermentation performance of the waste activated sludge with low concentration and low organic matter under PMS condition.
The waste activated sludge with low concentration and low organic matter was fermented under different conditions including natural, nanoscale zero-valent iron (nZVI), 2KHSO5·KHSO4·K2SO4(PMS), K2SO4, nZVI+PMS and nZVI+K2SO4. The soluble protein, polysaccharide, short volatile fatty acids (SCFAs) and biological enzyme were analyzed during the fermentation process, and the effects of nZVI on hydrolytic acidification performance of the excess sludge were studied. The results showed that hydrolytic acidification performance of the nZVI+PMS fermentation system was optimal, and the mass concentration of protein, polysaccharide and SCFAs was 255.07 mg/L, 138.31 mg/L and 356.8 mg/L respectively. The maximal activity of protease and α-glucosidase appeared in the nZVI+PMS fermentation system, however the maximal activity of alkaline phosphatase and acid phosphatase appeared in the nZVI fermentation system. In addition, the bioenzyme activity of the K2SO4 fermentation system was similar to that of natural fermentation system. These results indicated that nZVI could improve effectively the fermentation performance of the waste activated sludge with low concentration and low organic matter under PMS condition.
2022, 37(1)
:118-126.
doi: 10.12187/2022.01.016
Abstract:
Zhengmai 1354, Zhoumai 27, Zhoumai 30 and Zhengmai 9023 were selected as the research objects, and the effects of Cd with different concentrations (0 mg/L, 5 mg/L, 10 mg/L, 20 mg/L, 50 mg/L, 100 mg/L, 200 mg/L) on seed germination and seedling growth of different wheat varieties were studied by germination experiments of filter paper in culture dishes. The results showed that the germination potential, germination percentage, vigor index, root length and shoot length of Zhengmai 1354 reached the maximum when the concentration of Cd was 5 mg/L; The germination potential, germination percentage, germination index and vigor index of Zhoumai 27 increased at first and then decreased with the increase of Cd stress concentration. Both the germination potential and germination index of Zhoumai 30 and Zhengmai 9023 were lower than those of the control group under Cd stress concentration of 5~20 mg/L, meanwhile, the root length and shoot length of Zhengmai 9023 were significantly inhibited when Cd stress concentration was higher than 50 mg/L. The results of average value of subordinate function indicated that Zhoumai 27 had the highest Cd tolerance and high germination percentage (93%), which could be used as the best cultivar for Cd tolerance wheat.
Zhengmai 1354, Zhoumai 27, Zhoumai 30 and Zhengmai 9023 were selected as the research objects, and the effects of Cd with different concentrations (0 mg/L, 5 mg/L, 10 mg/L, 20 mg/L, 50 mg/L, 100 mg/L, 200 mg/L) on seed germination and seedling growth of different wheat varieties were studied by germination experiments of filter paper in culture dishes. The results showed that the germination potential, germination percentage, vigor index, root length and shoot length of Zhengmai 1354 reached the maximum when the concentration of Cd was 5 mg/L; The germination potential, germination percentage, germination index and vigor index of Zhoumai 27 increased at first and then decreased with the increase of Cd stress concentration. Both the germination potential and germination index of Zhoumai 30 and Zhengmai 9023 were lower than those of the control group under Cd stress concentration of 5~20 mg/L, meanwhile, the root length and shoot length of Zhengmai 9023 were significantly inhibited when Cd stress concentration was higher than 50 mg/L. The results of average value of subordinate function indicated that Zhoumai 27 had the highest Cd tolerance and high germination percentage (93%), which could be used as the best cultivar for Cd tolerance wheat.
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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
Subeditor：Qu Shuanghong
Edited & published by：Editorial Department of Journal of Light Industry
CN 41-1437/TS
ISSN 2096-1553
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