2023 Vol. 38, No. 6
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2023, 38(6)
:1-10.
doi: 10.12187/2023.06.001
Abstract:
Flaxseed gum (FG) and Artemisia sphaerocephala Krasch Gum (ASKG) were added into refined wheat flour to prepare frozen dough, and were treated with freeze-thaw cycle. The effects of these two hydrophilic colloid on the silty properties and gelatinization properties of wheat mixed flour, the water distribution and state, freezable water content (FW) and the microstructure of gluten protein in the frozen dough after freeze-thaw cycle treatment were investigated. The influences of these two hydrophilic colloid on specific volume (SP), stomata structure, texture and sensory quality of steamed bread were studied. The results showed that compared with blank control group, hydrophilic colloid could improve water absorption and flour quality index during dough formation, reduce the weakening degree of wheat mixed powder, and the stability time during dough formation was extended after ASKG was added. Hydrophilic colloid could improve the peak viscosity, disintegration value and recovery value of wheat mixed paste system, and the effect of ASKG was more significant than that of FG. The hydrophilic colloid could increase the strongly bound water content (A21) and decrease the free water content (A23) in the frozen dough. Under the same addition level, the ability of FG to regulate water distribution in the frozen dough was stronger than that of ASKG. Hydrophilic colloid could decrease FW in frozen dough and improve its frost resistance. Hydrophilic colloid could increase the SP, elasticity and resilience of steamed bread cooked by frozen dough, and reduce its hardness and chewability, that is, adding hydrophilic colloid could slow down the damage of gluten network structure caused by freeze-thaw cycle treatment, maintain its integrity and stability, improve the internal structure of steamed bread, and give it a soft and elastic texture.
Flaxseed gum (FG) and Artemisia sphaerocephala Krasch Gum (ASKG) were added into refined wheat flour to prepare frozen dough, and were treated with freeze-thaw cycle. The effects of these two hydrophilic colloid on the silty properties and gelatinization properties of wheat mixed flour, the water distribution and state, freezable water content (FW) and the microstructure of gluten protein in the frozen dough after freeze-thaw cycle treatment were investigated. The influences of these two hydrophilic colloid on specific volume (SP), stomata structure, texture and sensory quality of steamed bread were studied. The results showed that compared with blank control group, hydrophilic colloid could improve water absorption and flour quality index during dough formation, reduce the weakening degree of wheat mixed powder, and the stability time during dough formation was extended after ASKG was added. Hydrophilic colloid could improve the peak viscosity, disintegration value and recovery value of wheat mixed paste system, and the effect of ASKG was more significant than that of FG. The hydrophilic colloid could increase the strongly bound water content (A21) and decrease the free water content (A23) in the frozen dough. Under the same addition level, the ability of FG to regulate water distribution in the frozen dough was stronger than that of ASKG. Hydrophilic colloid could decrease FW in frozen dough and improve its frost resistance. Hydrophilic colloid could increase the SP, elasticity and resilience of steamed bread cooked by frozen dough, and reduce its hardness and chewability, that is, adding hydrophilic colloid could slow down the damage of gluten network structure caused by freeze-thaw cycle treatment, maintain its integrity and stability, improve the internal structure of steamed bread, and give it a soft and elastic texture.
2023, 38(6)
:11-17.
doi: 10.12187/2023.06.002
Abstract:
The changes of freezing curve and moisture uniformity during the freezing process of dough with different water(40%、45%、50% and 55%) additions at -18~25℃ were studied, and the effects of ice crystal growth on the network structure of gluten protein and the chemical forces during dough freezing were studied with 45% water addition as an example. The results showed that:the moisture uniformity showed a decreasing trend with different water additions during the dough freezing process. With the increase of water addition, the freezing rate of the dough first increased and then decreased, and the freezing rate was fastest when the water addition was 45%. With the decrease of temperature, the number decreased during the freezing process, the average pore area of ice crystals in the dough with 45% water addition increased, and it increased rapidly in the temperature range of -6℃ to -9℃; The number of pores decreased continuously, the branching rate of gluten protein network structure parameter gradually decreased from 2.20×10-3 to 1.90×10-3, and the endpoint rate gradually increased from 2.10×10-3 to 2.40×10-3. The hydrogen bonds, ionic bonds, and disulfide bonds between gluten protein network gradually weakened, and the gluten protein network was destroyed.
The changes of freezing curve and moisture uniformity during the freezing process of dough with different water(40%、45%、50% and 55%) additions at -18~25℃ were studied, and the effects of ice crystal growth on the network structure of gluten protein and the chemical forces during dough freezing were studied with 45% water addition as an example. The results showed that:the moisture uniformity showed a decreasing trend with different water additions during the dough freezing process. With the increase of water addition, the freezing rate of the dough first increased and then decreased, and the freezing rate was fastest when the water addition was 45%. With the decrease of temperature, the number decreased during the freezing process, the average pore area of ice crystals in the dough with 45% water addition increased, and it increased rapidly in the temperature range of -6℃ to -9℃; The number of pores decreased continuously, the branching rate of gluten protein network structure parameter gradually decreased from 2.20×10-3 to 1.90×10-3, and the endpoint rate gradually increased from 2.10×10-3 to 2.40×10-3. The hydrogen bonds, ionic bonds, and disulfide bonds between gluten protein network gradually weakened, and the gluten protein network was destroyed.
2023, 38(6)
:18-27.
doi: 10.12187/2023.06.003
Abstract:
In order to reduce the adverse effects of bran on whole wheat flour products, the bran was modified by cellulase and xylanase in cooperation with basidiomycetes, and then it was added back to wheat flour to prepare recombinant whole wheat flour and its noodles. The effects of bacteria-enzymes synergistic modified bran on the quality of recombinant whole wheat flour and its noodles were investigated by determining the powder properties, dynamic rheological properties, and mechanical, cooking, and textural properties of whole wheat noodles. The results showed that compared with the unmodified bran, the content of the components of the bran changed significantly after 5 days of synergistic modification. The content of insoluble dietary fiber (IDF) decreased by 20.5%, the content of protein increased by 16.1%, and the content of soluble arabinoxylan (WEAX) increased significantly by 442.6% (P<0.05). The quality index and stability time of recombinant whole wheat flour were significantly increased (P<0.05), and the dough viscoelasticity was increased. The cooking loss rate and breaking rate of whole wheat noodles were decreased, the breaking force and flexibility were increased, the hardness was significantly decreased, and the elasticity was significantly increased (P<0.05). In summary, the synergistic modification treatment of bacteria and enzymes improves the quality of recombinant whole wheat flour by degrading IDF in bran and increasing the content of soluble dietary fiber (SDF), thereby improving the quality of whole wheat noodles. Moreover, the quality of recombinant whole wheat flour and noodles fermented with bran for 5 days after enzymatic hydrolysis is better.
In order to reduce the adverse effects of bran on whole wheat flour products, the bran was modified by cellulase and xylanase in cooperation with basidiomycetes, and then it was added back to wheat flour to prepare recombinant whole wheat flour and its noodles. The effects of bacteria-enzymes synergistic modified bran on the quality of recombinant whole wheat flour and its noodles were investigated by determining the powder properties, dynamic rheological properties, and mechanical, cooking, and textural properties of whole wheat noodles. The results showed that compared with the unmodified bran, the content of the components of the bran changed significantly after 5 days of synergistic modification. The content of insoluble dietary fiber (IDF) decreased by 20.5%, the content of protein increased by 16.1%, and the content of soluble arabinoxylan (WEAX) increased significantly by 442.6% (P<0.05). The quality index and stability time of recombinant whole wheat flour were significantly increased (P<0.05), and the dough viscoelasticity was increased. The cooking loss rate and breaking rate of whole wheat noodles were decreased, the breaking force and flexibility were increased, the hardness was significantly decreased, and the elasticity was significantly increased (P<0.05). In summary, the synergistic modification treatment of bacteria and enzymes improves the quality of recombinant whole wheat flour by degrading IDF in bran and increasing the content of soluble dietary fiber (SDF), thereby improving the quality of whole wheat noodles. Moreover, the quality of recombinant whole wheat flour and noodles fermented with bran for 5 days after enzymatic hydrolysis is better.
2023, 38(6)
:28-36.
doi: 10.12187/2023.06.004
Abstract:
Medium gluten wheat flour was used as the main raw material to make wheat fermented pancakes.The effects of water addition, highly active dry yeast addition, fermentation time, baking temperature and baking time on the quality of wheat leavened pancakes were investigated by single-factor test with sensory score, specific volume, texture properties, and chroma as indexes.The response surface test was designed with sensory score as the response value to optimize the production process of wheat leavened pancakes.The results showed that under the conditions of water addition of 52%, yeast addition of 1.4%, fermentation time of 85 min, baking temperature of 210℃ and baking time of 14 min, the wheat leavened pancakes was golden yellow in colour, rich in flavor, soft and delicious, and the comprehensive sensory score was 91.50. This processing technology was easy to control and could be applied in practical production.
Medium gluten wheat flour was used as the main raw material to make wheat fermented pancakes.The effects of water addition, highly active dry yeast addition, fermentation time, baking temperature and baking time on the quality of wheat leavened pancakes were investigated by single-factor test with sensory score, specific volume, texture properties, and chroma as indexes.The response surface test was designed with sensory score as the response value to optimize the production process of wheat leavened pancakes.The results showed that under the conditions of water addition of 52%, yeast addition of 1.4%, fermentation time of 85 min, baking temperature of 210℃ and baking time of 14 min, the wheat leavened pancakes was golden yellow in colour, rich in flavor, soft and delicious, and the comprehensive sensory score was 91.50. This processing technology was easy to control and could be applied in practical production.
2023, 38(6)
:37-45.
doi: 10.12187/2023.06.005
Abstract:
On the basis of a brief description of the common types of antibiotics in animal derived food, the current status of antibiotic residues and hazards, focusing on antibiotic residue detection methods and research progress in animal source foods, it was pointed out that the main types of antibiotics were fluoroquinolones, β-lactams, macrolides, tetracyclines, nitrofurans, sulfonamides, amphenicols and aminoglycosides. Currently, antibiotic abuse caused serious residual problems, and the accumulation of antibiotics in the body could trigger allergic reactions, drug resistance and other symptoms. Antibiotic detection methods mainly included chromatography, spectrometry, electrochemistry, enzyme-linked immunosorbent assay (ELISA) and chemical sensing, which respectively suffered from the problems of complicated pre-treatment process, weak anti-interference ability, susceptibility to false positives, fewer types of detection, and difficulty in realising the simultaneous detection of a variety of antibiotics, and so on. Compared with other methods, chemical sensing had the advantages of simple and rapid process, obvious color change reaction, and enormous potential for application in the detection of antibiotic residues. In the future, the structural characteristics of antibiotics can be analysed in depth, and sensors detecting a variety of antibiotics simultaneously can be developed, thus further promoting the development of rapid and accurate detection of antibiotic residues in animal derived food.
On the basis of a brief description of the common types of antibiotics in animal derived food, the current status of antibiotic residues and hazards, focusing on antibiotic residue detection methods and research progress in animal source foods, it was pointed out that the main types of antibiotics were fluoroquinolones, β-lactams, macrolides, tetracyclines, nitrofurans, sulfonamides, amphenicols and aminoglycosides. Currently, antibiotic abuse caused serious residual problems, and the accumulation of antibiotics in the body could trigger allergic reactions, drug resistance and other symptoms. Antibiotic detection methods mainly included chromatography, spectrometry, electrochemistry, enzyme-linked immunosorbent assay (ELISA) and chemical sensing, which respectively suffered from the problems of complicated pre-treatment process, weak anti-interference ability, susceptibility to false positives, fewer types of detection, and difficulty in realising the simultaneous detection of a variety of antibiotics, and so on. Compared with other methods, chemical sensing had the advantages of simple and rapid process, obvious color change reaction, and enormous potential for application in the detection of antibiotic residues. In the future, the structural characteristics of antibiotics can be analysed in depth, and sensors detecting a variety of antibiotics simultaneously can be developed, thus further promoting the development of rapid and accurate detection of antibiotic residues in animal derived food.
2023, 38(6)
:46-51.
doi: 10.12187/2023.06.006
Abstract:
To the increasing difficulty of the detection of multi-pesticide residues in cowpea, optimized moving window target conversion factor analysis (OMWTTFA) algorithm was proposed, in which an adaptive iterative re-weighted penalized least squares calculation had been added to the moving window target transfer factor analysis (MWTTFA) algorithm. And a new method for non-targeted detection of multi-pesticide residues in cowpea was established by combining with gas chromatography-mass spectrometry (GC-MS). A mass spectrometry database of 500 common pesticides was established and high throughput analysis of cowpea GC-MS data was realized by using OMWTTFA algorithm. The method was verified with actual cowpea and spiked samples. The results showed that the method could realize non-targeted detection of all pesticide residues in the two groups of spiked cowpea samples within 30 min retention time, while no pesticide residues were detected in the actual cowpea samples. The matching values of all components were larger than 800‰, and this method was more accurate than MWTTFA algorithm. The above results showed that this method promised to become a new way for non-targeted and high-throughput detection of multi-pesticide residues in fruits and vegetables.
To the increasing difficulty of the detection of multi-pesticide residues in cowpea, optimized moving window target conversion factor analysis (OMWTTFA) algorithm was proposed, in which an adaptive iterative re-weighted penalized least squares calculation had been added to the moving window target transfer factor analysis (MWTTFA) algorithm. And a new method for non-targeted detection of multi-pesticide residues in cowpea was established by combining with gas chromatography-mass spectrometry (GC-MS). A mass spectrometry database of 500 common pesticides was established and high throughput analysis of cowpea GC-MS data was realized by using OMWTTFA algorithm. The method was verified with actual cowpea and spiked samples. The results showed that the method could realize non-targeted detection of all pesticide residues in the two groups of spiked cowpea samples within 30 min retention time, while no pesticide residues were detected in the actual cowpea samples. The matching values of all components were larger than 800‰, and this method was more accurate than MWTTFA algorithm. The above results showed that this method promised to become a new way for non-targeted and high-throughput detection of multi-pesticide residues in fruits and vegetables.
2023, 38(6)
:52-61.
doi: 10.12187/2023.06.007
Abstract:
To achieve accurate and highly sensitive determination of advanced glycation end products (AGEs) in baked food, a magnetic solid phase extraction (MSPE) technique based on magnetic covalent organic frameworks (COFs) material was established to achieve the selective and efficient enrichment of two major AGEs (i.e. Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL)) in baked foods. The quantitative analysis of CML and CEL was conducted with high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method. Results showed that the synthesized magnetic COFs material showed big specific surface area and strong magnetism, which was suitable for MSPE. The optimum conditions of MSPE were as follows:the amount of adsorbent was 20 mg, the time of vortex extraction was 20 min, the elution solvent was 5% ammonia/methanol solution, the volume of elution solvent was 4 mL, the elution time was 15 min. The limits of detection of CML and CEL for the established method were 2.05 ng/mL and 2.31 ng/mL, respectively, while the limits of quantification were 6.83 ng/mL and 7.71 ng/mL, respectively. And intra-day and inter-day precisions were good (RSDintra-day ≤ 4.74%, RSDinter-day ≤ 5.38%). The recoveries of CML and CEL in typical food matrixes (i.e. biscuits and nuts) were in the range of 90.70%~108.74% and 85.50%~113.00%, respectively. Applying the analytical method established in this article to the determination of CML and CEL contents in 26 commercially available baked goods, it was found that the contents of CML and CEL in biscuits and pastries were in the range of (9.60±0.16)~(78.10±1.12) mg/kg, and (4.37±0.23)~(26.70±1.27) mg/kg, respectively; while the contents of CML and CEL in nuts were in the range of (6.49±0.13)~(82.00±0.98) mg/kg, and (6.65±0.30)~(55.90±0.67) mg/kg, respectively. The established method could effectively purify samples and significantly reduce matrix effect, and thus showed high accuracy for quantitative analysis. Furthermore, the synthesized magnetic COFs material could be recycled for 5 times, which was suitable for the determination of CML and CEL in baked food.
To achieve accurate and highly sensitive determination of advanced glycation end products (AGEs) in baked food, a magnetic solid phase extraction (MSPE) technique based on magnetic covalent organic frameworks (COFs) material was established to achieve the selective and efficient enrichment of two major AGEs (i.e. Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL)) in baked foods. The quantitative analysis of CML and CEL was conducted with high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method. Results showed that the synthesized magnetic COFs material showed big specific surface area and strong magnetism, which was suitable for MSPE. The optimum conditions of MSPE were as follows:the amount of adsorbent was 20 mg, the time of vortex extraction was 20 min, the elution solvent was 5% ammonia/methanol solution, the volume of elution solvent was 4 mL, the elution time was 15 min. The limits of detection of CML and CEL for the established method were 2.05 ng/mL and 2.31 ng/mL, respectively, while the limits of quantification were 6.83 ng/mL and 7.71 ng/mL, respectively. And intra-day and inter-day precisions were good (RSDintra-day ≤ 4.74%, RSDinter-day ≤ 5.38%). The recoveries of CML and CEL in typical food matrixes (i.e. biscuits and nuts) were in the range of 90.70%~108.74% and 85.50%~113.00%, respectively. Applying the analytical method established in this article to the determination of CML and CEL contents in 26 commercially available baked goods, it was found that the contents of CML and CEL in biscuits and pastries were in the range of (9.60±0.16)~(78.10±1.12) mg/kg, and (4.37±0.23)~(26.70±1.27) mg/kg, respectively; while the contents of CML and CEL in nuts were in the range of (6.49±0.13)~(82.00±0.98) mg/kg, and (6.65±0.30)~(55.90±0.67) mg/kg, respectively. The established method could effectively purify samples and significantly reduce matrix effect, and thus showed high accuracy for quantitative analysis. Furthermore, the synthesized magnetic COFs material could be recycled for 5 times, which was suitable for the determination of CML and CEL in baked food.
2023, 38(6)
:62-69.
doi: 10.12187/2023.06.008
Abstract:
A highly active G4 DNAzyme-peptide complex obtained by covalent assembly of cationic peptide on G4 DNAzyme was used to construct a novel electrochemical aptasensor. The effect of complex on the performance of electrochemical aptasensor was investigated and the proposed aptasensor was used to detect kanamycin (KANA) in milk. The experimental results indicated that G4 DNAzyme-peptide could significantly amplify the electrochemical signal and greatly improve the detection sensitivity of aptasensor. Under the optimal concentration of capture probe (CP, 2.0 μmol/L), the change of current intensity showed a good linear relationship with the logarithm of the target concentration in the range of 0.06 pmol/L~20 nmol/L, and the detection limit was 0.02 pmol/L, which was superior to other KANA detection methods. The aptasensor showed better selectivity and lower detection limit and the recoveries obtained in milk sample were from 97.1% to 105.5% and the relative standard deviation were from 3.60% to 5.74%. The experimental results were consistent with ELISA method, indicating the proposed aptasensor could achieve high sensitivity for the detection of KANA in milk.
A highly active G4 DNAzyme-peptide complex obtained by covalent assembly of cationic peptide on G4 DNAzyme was used to construct a novel electrochemical aptasensor. The effect of complex on the performance of electrochemical aptasensor was investigated and the proposed aptasensor was used to detect kanamycin (KANA) in milk. The experimental results indicated that G4 DNAzyme-peptide could significantly amplify the electrochemical signal and greatly improve the detection sensitivity of aptasensor. Under the optimal concentration of capture probe (CP, 2.0 μmol/L), the change of current intensity showed a good linear relationship with the logarithm of the target concentration in the range of 0.06 pmol/L~20 nmol/L, and the detection limit was 0.02 pmol/L, which was superior to other KANA detection methods. The aptasensor showed better selectivity and lower detection limit and the recoveries obtained in milk sample were from 97.1% to 105.5% and the relative standard deviation were from 3.60% to 5.74%. The experimental results were consistent with ELISA method, indicating the proposed aptasensor could achieve high sensitivity for the detection of KANA in milk.
2023, 38(6)
:70-77.
doi: 10.12187/2023.06.009
Abstract:
Coix seeds from 9 different origins were taken as the research object. An attempt was made to achieve geographical origin traceability of Coix seeds through the combination of excitation-emission matrix (EEM) fluorescence spectroscopy with improved random forest algorithm. The improvements to the random forest algorithm mainly include two aspects, firstly, principal component analysis (PCA) was adopted to reduce the dimension of EEM fluorescent data; secondly, a grid search method was used to identify the optimal number of principal components(PCs) to retain and the hyperparameters of the discriminant model during the PCA dimension reduction process. The results showed that an improved random forest model, incorporating standard deviation normalization and PCA dimension reduction modules, based on Coix seeds EEM fluorescence spectroscopy data, accurately predicted the geographical origin of Coix seed samples from 9 different areas. The optimal model was constructed by combining 100 decision trees with a maximum depth of 3 and a minimum sample size of 1 at the leaf node, using 16 principal components (PCs). This model achieved 100% prediction accuracy for both the validation and test sets, which consisted of a total of 108 samples, outperforming the PLS-DA model constructed by the partial least squares method (96% prediction accuracy).
Coix seeds from 9 different origins were taken as the research object. An attempt was made to achieve geographical origin traceability of Coix seeds through the combination of excitation-emission matrix (EEM) fluorescence spectroscopy with improved random forest algorithm. The improvements to the random forest algorithm mainly include two aspects, firstly, principal component analysis (PCA) was adopted to reduce the dimension of EEM fluorescent data; secondly, a grid search method was used to identify the optimal number of principal components(PCs) to retain and the hyperparameters of the discriminant model during the PCA dimension reduction process. The results showed that an improved random forest model, incorporating standard deviation normalization and PCA dimension reduction modules, based on Coix seeds EEM fluorescence spectroscopy data, accurately predicted the geographical origin of Coix seed samples from 9 different areas. The optimal model was constructed by combining 100 decision trees with a maximum depth of 3 and a minimum sample size of 1 at the leaf node, using 16 principal components (PCs). This model achieved 100% prediction accuracy for both the validation and test sets, which consisted of a total of 108 samples, outperforming the PLS-DA model constructed by the partial least squares method (96% prediction accuracy).
2023, 38(6)
:78-84,117.
doi: 10.12187/2023.06.010
Abstract:
To study the genes regulating the synthesis of sugar esters in tobacco, transcriptome sequencing analysis was performed on tobacco glandular hair cells and bundle sheath cells, and RT-qPCR was used for verification. The results showed that 11 962 differentially expressed genes were obtained, of which 5145 were up-regulated and 6817 were down-regulated.GO annotation of differentially expressed genes showed that the up-regulated genes mainly included biological processes (2265), molecular functions (1169), and cellular components (363), with a total of 3793 GO terms. Based on the assignment of KEGG pathway, the sequence was mapped to 122 metabolic pathways. Glycolysis/gluconeogenesis, starch and sucrose metabolism, phenylpropanoid biosynthesis related to glycoester synthesis were highly enriched, and acyl sugar pathway in glandular hairs was significantly up-regulated. By comparing with the tobacco reference genome, 12 up-regulated acyltransferase genes were identified in glandular hair cells. RT-qPCR results showed that the expression of 11 genes was higher than that of the control. The expression of gene 63826, gene 16194 and gene 37511 increased by 195.79 times, 166.23 times and 132.65 times, respectively. The above 11 genes may be involved in regulating the synthesis of sugar esters in glandular hair cells, providing a basis for further verification of gene function.
To study the genes regulating the synthesis of sugar esters in tobacco, transcriptome sequencing analysis was performed on tobacco glandular hair cells and bundle sheath cells, and RT-qPCR was used for verification. The results showed that 11 962 differentially expressed genes were obtained, of which 5145 were up-regulated and 6817 were down-regulated.GO annotation of differentially expressed genes showed that the up-regulated genes mainly included biological processes (2265), molecular functions (1169), and cellular components (363), with a total of 3793 GO terms. Based on the assignment of KEGG pathway, the sequence was mapped to 122 metabolic pathways. Glycolysis/gluconeogenesis, starch and sucrose metabolism, phenylpropanoid biosynthesis related to glycoester synthesis were highly enriched, and acyl sugar pathway in glandular hairs was significantly up-regulated. By comparing with the tobacco reference genome, 12 up-regulated acyltransferase genes were identified in glandular hair cells. RT-qPCR results showed that the expression of 11 genes was higher than that of the control. The expression of gene 63826, gene 16194 and gene 37511 increased by 195.79 times, 166.23 times and 132.65 times, respectively. The above 11 genes may be involved in regulating the synthesis of sugar esters in glandular hair cells, providing a basis for further verification of gene function.
2023, 38(6)
:85-92.
doi: 10.12187/2023.06.011
Abstract:
To solve the problems of dense structure of tobacco stalk, strong nicotine inhibition and low conversion efficiency of cellulosic sugars, the tobacco stalks were pretreated with Irpex lacteus. The composition and structure changes of tobacco stalks before and after pretreatment were compared to study the effects of I. lacteus pretreatment on enzymatic hydrolysis and saccharification of tobacco stalks. The conversion rate of lactic acid from tobacco stalks fermented by Bacillus coagulans under different fermentation conditions (simultaneous saccharification fermentation, batch fermentation) was further compared. The results showed that the mass fraction of lignin in the tobacco stalks was reduced by 44.90% compared with that of the raw tobacco stalks. Biological pretreatment using I. lacteus could selectively destroy the macromolecular structure of lignin, and the benzene ring structure and side chain groups of lignin were also degraded. The reactivity of cellulose in tobacco stalks was improved after pretreatment with I. lacteus and the yield of glucose was 260 mg/g, which was enhanced by 2.25 times compared with raw tobacco stalks. Compared with batch fermentation, the lactic acid yield of simultaneous saccharification fermentation was higher (392.16 mg/g), and the conversion rate of lactic acid reached 86.95%, which was 3.78 times higher than that of raw tobacco stalks. The pretreatment of I. lacteus could selectively degrade lignin of tobacco stalks, reduce the resistance of enzymatic hydrolysis to saccharification of tobacco stalks and increase the conversion rate of lactic acid of tobacco stalks.
To solve the problems of dense structure of tobacco stalk, strong nicotine inhibition and low conversion efficiency of cellulosic sugars, the tobacco stalks were pretreated with Irpex lacteus. The composition and structure changes of tobacco stalks before and after pretreatment were compared to study the effects of I. lacteus pretreatment on enzymatic hydrolysis and saccharification of tobacco stalks. The conversion rate of lactic acid from tobacco stalks fermented by Bacillus coagulans under different fermentation conditions (simultaneous saccharification fermentation, batch fermentation) was further compared. The results showed that the mass fraction of lignin in the tobacco stalks was reduced by 44.90% compared with that of the raw tobacco stalks. Biological pretreatment using I. lacteus could selectively destroy the macromolecular structure of lignin, and the benzene ring structure and side chain groups of lignin were also degraded. The reactivity of cellulose in tobacco stalks was improved after pretreatment with I. lacteus and the yield of glucose was 260 mg/g, which was enhanced by 2.25 times compared with raw tobacco stalks. Compared with batch fermentation, the lactic acid yield of simultaneous saccharification fermentation was higher (392.16 mg/g), and the conversion rate of lactic acid reached 86.95%, which was 3.78 times higher than that of raw tobacco stalks. The pretreatment of I. lacteus could selectively degrade lignin of tobacco stalks, reduce the resistance of enzymatic hydrolysis to saccharification of tobacco stalks and increase the conversion rate of lactic acid of tobacco stalks.
2023, 38(6)
:93-101.
doi: 10.12187/2023.06.012
Abstract:
The differences and their correlation in conventional chemical composition, fragrance-causing components and microbial community structure of cigar wrapper leaves before and after fermentation as well as metabolic pathway change were analyzed in this study to explore the mechanism of B.velezensis H1 on the flavoring and quality enhancement of cigar wrapper leaves. The results showed that relative contents of nicotine, total nitrogen and potassium were significantly changed after adding exogenous B.velezensis H1. The types and the content of aroma substances in cigar wrapper leaves treated with B.velezensis H1 increased significantly, such as phytol, geranylacetone and neophytadiene, which could effectively improve the quality of flue gas to be pure and mild. After fermentation, the bacterial diversity on the surface of cigar wrapper leaves changed significantly, and the number of OTUs was increased after B.velezensis H1 inoculation. The bacterial community structure and dominant flora on the surface of tobacco leaves were changed. The dominant phylum changed from Firmicutes to Actinobacteriota after treated with B.velezensis H1. The dominant genus evolved from Staphylococcus to Staphylococcus, Yaniella, unclassified_fMicrococcaceae. The top five metabolic pathways of significant changes due to microbial community structure transformation were global and overview maps, carbohydrate metabolism, amino acid metabolism, metabolism of cofactors and vitamins, and energy metabolism. The results of correlation analysis showed that key substances such as reducing sugar, total nitrogen, nicotine, chlorine, total sugar, and potassium were greatly influenced by the bacterial community of cigar wrapper leaves. Generation of phenylethanol was related to Staphylococcus, Corynebacterium, and Oceanobacillus. Geranylacetone formation was closely related to Micrococcus, Oceanobacillus, and Enteractinococcus.
The differences and their correlation in conventional chemical composition, fragrance-causing components and microbial community structure of cigar wrapper leaves before and after fermentation as well as metabolic pathway change were analyzed in this study to explore the mechanism of B.velezensis H1 on the flavoring and quality enhancement of cigar wrapper leaves. The results showed that relative contents of nicotine, total nitrogen and potassium were significantly changed after adding exogenous B.velezensis H1. The types and the content of aroma substances in cigar wrapper leaves treated with B.velezensis H1 increased significantly, such as phytol, geranylacetone and neophytadiene, which could effectively improve the quality of flue gas to be pure and mild. After fermentation, the bacterial diversity on the surface of cigar wrapper leaves changed significantly, and the number of OTUs was increased after B.velezensis H1 inoculation. The bacterial community structure and dominant flora on the surface of tobacco leaves were changed. The dominant phylum changed from Firmicutes to Actinobacteriota after treated with B.velezensis H1. The dominant genus evolved from Staphylococcus to Staphylococcus, Yaniella, unclassified_fMicrococcaceae. The top five metabolic pathways of significant changes due to microbial community structure transformation were global and overview maps, carbohydrate metabolism, amino acid metabolism, metabolism of cofactors and vitamins, and energy metabolism. The results of correlation analysis showed that key substances such as reducing sugar, total nitrogen, nicotine, chlorine, total sugar, and potassium were greatly influenced by the bacterial community of cigar wrapper leaves. Generation of phenylethanol was related to Staphylococcus, Corynebacterium, and Oceanobacillus. Geranylacetone formation was closely related to Micrococcus, Oceanobacillus, and Enteractinococcus.
2023, 38(6)
:102-109.
doi: 10.12187/2023.06.013
Abstract:
To address the problems of slow detection speed and low accuracy commonly found in cigarette factory warehouse workshops when detecting tobacco moth, a visual detection method for tobacco moth in cigarette factories based on improved lightweight YOLOv5s was developed. The method utilizes the correlation and redundancy between feature maps to design the EESP-Ghost module, and uses this module as the basis for designing a double-attention Ghost-bneck block incorporating an efficient spatial pyramid, which is introduced into the YOLOv5s model to achieve lightweighting of the deep neural network model while improving the detection accuracy. The method is used for validation experiments on the tobacco moth dataset. The results showed that the method improved the average accuracy by 4.37% with only 49.88% of the original YOLOv5s parameter count. When the tobacco moth adhering to the sticky board was detected in a real detection scenario, the method has high detection confidence and correct detection number, which could realize the high-precision real-time detection of the tobacco moth in the cigarette factory, and provide a guarantee for the effective control of the tobacco moth.
To address the problems of slow detection speed and low accuracy commonly found in cigarette factory warehouse workshops when detecting tobacco moth, a visual detection method for tobacco moth in cigarette factories based on improved lightweight YOLOv5s was developed. The method utilizes the correlation and redundancy between feature maps to design the EESP-Ghost module, and uses this module as the basis for designing a double-attention Ghost-bneck block incorporating an efficient spatial pyramid, which is introduced into the YOLOv5s model to achieve lightweighting of the deep neural network model while improving the detection accuracy. The method is used for validation experiments on the tobacco moth dataset. The results showed that the method improved the average accuracy by 4.37% with only 49.88% of the original YOLOv5s parameter count. When the tobacco moth adhering to the sticky board was detected in a real detection scenario, the method has high detection confidence and correct detection number, which could realize the high-precision real-time detection of the tobacco moth in the cigarette factory, and provide a guarantee for the effective control of the tobacco moth.
2023, 38(6)
:110-117.
doi: 10.12187/2023.06.014
Abstract:
The process of drum drying silk has complex characteristics of multivariability, strong coupling, and nonlinearity. Traditional Principal Component Analysis (PCA) method lacks strong nonlinear ability, and global modeling method is difficult to achieve accurate fault detection of the process.Therefore, this paper proposed a novel multi-block approach by integrating Autoencoder (AE) for feature extraction and PCA model.Initially, in order to capture local features, the process variables were divided into blocks according to the drying process principle of tobacco leaf.Secondly, autoencoder was used to extract the nonlinear features of each sub-block.Then, the corresponding PCA models are established for each sub-block, respectively.Lastly, the monitoring results of multiple subspaces were fused for decision-making by Bayesian inference. Two actual leaf silk drying cases were used for verification, and the results showed that the alarm rates of this method were as high as 91.67% and 98.21%. Compared to traditional PCA and AE-PCA detection methods, this algorithm could accurately reveal and characterize the overall operating status and local feature information of the drying process, improve the accuracy of anomaly detection in the drum leaf silk drying production process and achieve accurate alarm for quality anomalies, to ensure stable production of the drum leaf silk drying process.
The process of drum drying silk has complex characteristics of multivariability, strong coupling, and nonlinearity. Traditional Principal Component Analysis (PCA) method lacks strong nonlinear ability, and global modeling method is difficult to achieve accurate fault detection of the process.Therefore, this paper proposed a novel multi-block approach by integrating Autoencoder (AE) for feature extraction and PCA model.Initially, in order to capture local features, the process variables were divided into blocks according to the drying process principle of tobacco leaf.Secondly, autoencoder was used to extract the nonlinear features of each sub-block.Then, the corresponding PCA models are established for each sub-block, respectively.Lastly, the monitoring results of multiple subspaces were fused for decision-making by Bayesian inference. Two actual leaf silk drying cases were used for verification, and the results showed that the alarm rates of this method were as high as 91.67% and 98.21%. Compared to traditional PCA and AE-PCA detection methods, this algorithm could accurately reveal and characterize the overall operating status and local feature information of the drying process, improve the accuracy of anomaly detection in the drum leaf silk drying production process and achieve accurate alarm for quality anomalies, to ensure stable production of the drum leaf silk drying process.
2023, 38(6)
:118-126.
doi: 10.12187/2023.06.015
Abstract:
In order to avoid environmental pollution and resource waste produced during the production and processing of tobacco, this paper systematically reviewed the current status of fuel utilization of tobacco and its wastes and showed that:The preparation method of tobacco solid fuel was simple and convenient, but the requirements for equipment were high. Among them, tobacco briquette charcoal was more easily transported and stored, clean and environmentally friendly, furthermore, the combustion residue could also be used for secondary utilization in agriculture.The preparation method of liquid fuel preparation was relatively mature. The operation of the direct extraction technology was simple, but the bio-oil yield depended on the inherent fat content in tobacco raw materials. Therofore, it required higher requirements for tobacco varieties. The thermal chemical conversion method belonged to a chemical process with high energy consumption, but there is a large space for innovation with regard to the preparation method. The chemical composition of liquid fuels could be adjusted, having a huge development potential. The fermentation method produced a single product, mainly ethanol, with low efficiency at present. There has been no breakthrough in the pretreatment technology for scalable application of tobacco raw materials throughout the entire technical chain.The preparation method of gaseous fuel was still in the exploration stage, with high energy consumption and low yield. The tech-economic feasibility was poor. In the future, much more attention should be paid on tobacco briquette charcoal, tobacco fermentation for fuel ethanol production, tobacco catalytic pyrolysis for liquid fuel, as well as the cultivation of novel tobacco varieties targeted towards specific energy purpose. This will further promote the industrialized development of multiple purposes of tobacco.
In order to avoid environmental pollution and resource waste produced during the production and processing of tobacco, this paper systematically reviewed the current status of fuel utilization of tobacco and its wastes and showed that:The preparation method of tobacco solid fuel was simple and convenient, but the requirements for equipment were high. Among them, tobacco briquette charcoal was more easily transported and stored, clean and environmentally friendly, furthermore, the combustion residue could also be used for secondary utilization in agriculture.The preparation method of liquid fuel preparation was relatively mature. The operation of the direct extraction technology was simple, but the bio-oil yield depended on the inherent fat content in tobacco raw materials. Therofore, it required higher requirements for tobacco varieties. The thermal chemical conversion method belonged to a chemical process with high energy consumption, but there is a large space for innovation with regard to the preparation method. The chemical composition of liquid fuels could be adjusted, having a huge development potential. The fermentation method produced a single product, mainly ethanol, with low efficiency at present. There has been no breakthrough in the pretreatment technology for scalable application of tobacco raw materials throughout the entire technical chain.The preparation method of gaseous fuel was still in the exploration stage, with high energy consumption and low yield. The tech-economic feasibility was poor. In the future, much more attention should be paid on tobacco briquette charcoal, tobacco fermentation for fuel ethanol production, tobacco catalytic pyrolysis for liquid fuel, as well as the cultivation of novel tobacco varieties targeted towards specific energy purpose. This will further promote the industrialized development of multiple purposes of tobacco.
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
Subeditor：Qu Shuanghong
Edited & published by：Editorial Department of Journal of Light Industry
CN 41-1437/TS
ISSN 2096-1553
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