2022 Vol. 37, No. 4
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2022, 37(4)
:1-9.
doi: 10.12187/2022.04.001
Abstract:
Aspergillus amstelodami A1 isolated from Pu-erh tea was inoculated in sterilized or unsterilized sun-dried green tea leaves to develop pure culture fermentation and enhanced fermentation (EF) of Pu-erh tea. The results showed that the content of tea polyphenols and five catechins in tea decreased significantly, and the content of thearubigins and theabrownins increased significantly after pure culture fermentation. Compared with natural fermentation, the levels of soluble sugars and theabrownins in EF were significantly higher, whereas the levels of gallic acid, (+)-catechin, (-)-epicatechin, (-)-epigallocatechin and caffeine were significantly lower; the scores of sensory evaluation including appearance, color of infusion, taste ,aroma and infused leaves in EF were significantly higher; while the value of a* and b* of EF's tea infusion were higher and the value of L* was lower. A.amstelodami A1 didn't become the dominant fungi in EF, while the microbial communities in EF were different from those in NF. Therefore, the enhanced fermentation by inoculation of A.amstelodami A1 changed the chemical components of tea leaves through the synergistic effect with other microorganisms, therefore improving the sensory quality of Pu-erh tea.
Aspergillus amstelodami A1 isolated from Pu-erh tea was inoculated in sterilized or unsterilized sun-dried green tea leaves to develop pure culture fermentation and enhanced fermentation (EF) of Pu-erh tea. The results showed that the content of tea polyphenols and five catechins in tea decreased significantly, and the content of thearubigins and theabrownins increased significantly after pure culture fermentation. Compared with natural fermentation, the levels of soluble sugars and theabrownins in EF were significantly higher, whereas the levels of gallic acid, (+)-catechin, (-)-epicatechin, (-)-epigallocatechin and caffeine were significantly lower; the scores of sensory evaluation including appearance, color of infusion, taste ,aroma and infused leaves in EF were significantly higher; while the value of a* and b* of EF's tea infusion were higher and the value of L* was lower. A.amstelodami A1 didn't become the dominant fungi in EF, while the microbial communities in EF were different from those in NF. Therefore, the enhanced fermentation by inoculation of A.amstelodami A1 changed the chemical components of tea leaves through the synergistic effect with other microorganisms, therefore improving the sensory quality of Pu-erh tea.
2022, 37(4)
:10-17.
doi: 10.12187/2022.04.002
Abstract:
Taking simulated sunlight as abiotic environmental stress condition, the fermentation conditions of carotenoid synthesis by Rhodotorula glutinis were optimized by single factor test and orthogonal test. The effects of hight stress on growth of Rhodotorula glutinis and carotenoid synthesis were studied. The results showed that the light intensity of 5000 Lux could significantly increase the biomass and carotenoid yield. The type of carbon sources had the greatest effect on carotenoid biosynthesis. Glycerol and glucose could be better used to synthesize carotenoids. The optimal fermentation conditions were glycerol concentration of 20 g/L, yeast powder addition of 3.5 g/L, the initial pH value 5.0 and temperature of 25 ℃. After cultured in 5 L fermentor for 144 h, the biomass and carotenoid yield reached 14.2 g/L and 17.3 mg/L, respectively, which were 24.5% and 21.0% higher than those before optimization; Light stress could not only increase the yield of carotenoids, but also effectively increase the proportion of high value-added carotenoids (torularhodin and torulene) in the product.
Taking simulated sunlight as abiotic environmental stress condition, the fermentation conditions of carotenoid synthesis by Rhodotorula glutinis were optimized by single factor test and orthogonal test. The effects of hight stress on growth of Rhodotorula glutinis and carotenoid synthesis were studied. The results showed that the light intensity of 5000 Lux could significantly increase the biomass and carotenoid yield. The type of carbon sources had the greatest effect on carotenoid biosynthesis. Glycerol and glucose could be better used to synthesize carotenoids. The optimal fermentation conditions were glycerol concentration of 20 g/L, yeast powder addition of 3.5 g/L, the initial pH value 5.0 and temperature of 25 ℃. After cultured in 5 L fermentor for 144 h, the biomass and carotenoid yield reached 14.2 g/L and 17.3 mg/L, respectively, which were 24.5% and 21.0% higher than those before optimization; Light stress could not only increase the yield of carotenoids, but also effectively increase the proportion of high value-added carotenoids (torularhodin and torulene) in the product.
2022, 37(4)
:18-25.
doi: 10.12187/2022.04.003
Abstract:
The effects of Enicilium roqueforti and Penicilium nalgiovense on the physical and chemical properties and microstructure of duck meat were studied. The results showed that compared with Enicilium roqueforti duck meat products, the hardness and elasticity of the duck meat fermented by Penicilium nalgiovense were lower, and the viscosity during post-fermentation stage was bigger, surface bound water content was lower, the surface of the duck meat was smoother. There was no myofibrillary structure in the two fermented duck meat products, and α-helix decreased and β-folding increased in the protein secondary structure. The fermentation of Penicilium nalgiovense produced more volatile flavor substances than Enicilium roqueforti and produced new aldehydes and alcohols. Penicilium nalgiovense was more suitable for fermentation of duck meat products.
The effects of Enicilium roqueforti and Penicilium nalgiovense on the physical and chemical properties and microstructure of duck meat were studied. The results showed that compared with Enicilium roqueforti duck meat products, the hardness and elasticity of the duck meat fermented by Penicilium nalgiovense were lower, and the viscosity during post-fermentation stage was bigger, surface bound water content was lower, the surface of the duck meat was smoother. There was no myofibrillary structure in the two fermented duck meat products, and α-helix decreased and β-folding increased in the protein secondary structure. The fermentation of Penicilium nalgiovense produced more volatile flavor substances than Enicilium roqueforti and produced new aldehydes and alcohols. Penicilium nalgiovense was more suitable for fermentation of duck meat products.
2022, 37(4)
:26-33.
doi: 10.12187/2022.04.004
Abstract:
A method of ionic liquid aqueous two-phase system, in which optimum extraction conditions were achieved by both single factor experiment and orthogonal experiment, combined with ultra-high performance liquid chromatography (UPLC), was established to detect Harman and Norharmane in vinegar. The experimental results showed that the optimum extraction conditions were as follows: [C6MIM]Br-K2HPO4 were used as the ionic liquid aqueous two-phase system, the amount of [C6MIM]Br was 200 μL, the amount of K2HPO4 was 0.5 g, pH value was 10, and the ultrasound time was 3 min. Under the appropriate optimal conditions, both the linear equations of Harman and Norharmane were 10.0~400.0 μg/mL, and both the correlation coefficients R2 were 0.999 5. The limits of detection (LODs) of Harman and Norharmane were 0.50 μg/mL and 0.45 μg/mL, respectively. All the precision experiment, repeatability experiment, and recovery experiment showed that the method had better accuracy and precision. That is, the method could be used for the determination of Harman and Norharmane in vinegar.
A method of ionic liquid aqueous two-phase system, in which optimum extraction conditions were achieved by both single factor experiment and orthogonal experiment, combined with ultra-high performance liquid chromatography (UPLC), was established to detect Harman and Norharmane in vinegar. The experimental results showed that the optimum extraction conditions were as follows: [C6MIM]Br-K2HPO4 were used as the ionic liquid aqueous two-phase system, the amount of [C6MIM]Br was 200 μL, the amount of K2HPO4 was 0.5 g, pH value was 10, and the ultrasound time was 3 min. Under the appropriate optimal conditions, both the linear equations of Harman and Norharmane were 10.0~400.0 μg/mL, and both the correlation coefficients R2 were 0.999 5. The limits of detection (LODs) of Harman and Norharmane were 0.50 μg/mL and 0.45 μg/mL, respectively. All the precision experiment, repeatability experiment, and recovery experiment showed that the method had better accuracy and precision. That is, the method could be used for the determination of Harman and Norharmane in vinegar.
2022, 37(4)
:34-40.
doi: 10.12187/2022.04.005
Abstract:
Bioinformatics methods were used to predict the hydrophilicity, hydrophobicity, antigen epitopes and analyse multiple sequence alignment of the nucleocapsid protein (N protein) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The recombinant plasmid pET28a/N was constructed. In the prokaryotic expression system of Escherichia coli, the solubility and expression level of the protein were improved by adjusting the change of induction temperature and time, and the expressed recombinant N protein was purified and identified. The results showed that SARS-CoV-2 N encoded 419 amino acids, with an isoelectric point (PI) of 10.10, no transmembrane region, no signal peptide sequence, and strong local hydrophilicity. The full-length protein had a high antigenic index and was highly conserved, and its homology with SARS-CoV N protein was 90.5%. After fermentation with Escherichia coli prokaryotic expression system, the engineering strain BL21 (DE3)/pET28a/N was induced at 16 ℃ for 20 h with the final IPTG concentration of 0.2 mmol/L, and the protein was soluble and most pressed at this time, accounting for 70% of the total protein expression. The target protein purified by Ni-NTA affinity chromatography and gel filtration chromatography had a purity of 90% and a molecular weight of 55 kDa, which was specific.
Bioinformatics methods were used to predict the hydrophilicity, hydrophobicity, antigen epitopes and analyse multiple sequence alignment of the nucleocapsid protein (N protein) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The recombinant plasmid pET28a/N was constructed. In the prokaryotic expression system of Escherichia coli, the solubility and expression level of the protein were improved by adjusting the change of induction temperature and time, and the expressed recombinant N protein was purified and identified. The results showed that SARS-CoV-2 N encoded 419 amino acids, with an isoelectric point (PI) of 10.10, no transmembrane region, no signal peptide sequence, and strong local hydrophilicity. The full-length protein had a high antigenic index and was highly conserved, and its homology with SARS-CoV N protein was 90.5%. After fermentation with Escherichia coli prokaryotic expression system, the engineering strain BL21 (DE3)/pET28a/N was induced at 16 ℃ for 20 h with the final IPTG concentration of 0.2 mmol/L, and the protein was soluble and most pressed at this time, accounting for 70% of the total protein expression. The target protein purified by Ni-NTA affinity chromatography and gel filtration chromatography had a purity of 90% and a molecular weight of 55 kDa, which was specific.
2022, 37(4)
:41-48,57.
doi: 10.12187/2022.04.006
Abstract:
Based on the brief introduction of the dangers of antibiotic residues and the current status of antibiotic detection technology, the fluorescence sensing methods based on carbon quantum dots, semiconductor quantum dots, metal-organic framework materials and upconversion nanomaterials for antibiotic detection application were reviewed. It pointed out that compared with traditional detection methods, fluorescence sensor detection method had the advantages of speediness, high sensitivity and visualization. However, due to the food matrix effect, complex sample pretreatment steps were often required to purify and enrich the target substance. Therefore, appropriate pretreatment technologies or matrix purification methods, new novel fluorescent nanomaterials, portable sensing detection equipment suitable for on-site detection,and the specificity of detection by combining aptamer,antibody and molecular imprinting techniques were the technological trend. It was expected that this review was able to provide a reference and theoretical basis for the practical applications of fluorescence sensing technology in antibiotic detection in the future.
Based on the brief introduction of the dangers of antibiotic residues and the current status of antibiotic detection technology, the fluorescence sensing methods based on carbon quantum dots, semiconductor quantum dots, metal-organic framework materials and upconversion nanomaterials for antibiotic detection application were reviewed. It pointed out that compared with traditional detection methods, fluorescence sensor detection method had the advantages of speediness, high sensitivity and visualization. However, due to the food matrix effect, complex sample pretreatment steps were often required to purify and enrich the target substance. Therefore, appropriate pretreatment technologies or matrix purification methods, new novel fluorescent nanomaterials, portable sensing detection equipment suitable for on-site detection,and the specificity of detection by combining aptamer,antibody and molecular imprinting techniques were the technological trend. It was expected that this review was able to provide a reference and theoretical basis for the practical applications of fluorescence sensing technology in antibiotic detection in the future.
2022, 37(4)
:49-57.
doi: 10.12187/2022.04.007
Abstract:
The current situation, causes and solutions of the nutritional imbalance of young football players at home and abroad were summarized. It was pointed out that the imbalance of energy and material intake were mainly caused by insufficient total energy and carbohydrate intake and excessive protein and fat intake, with obvious regional characteristics; The main causes of nutritional imbalance were lack of nutrition knowledge, insufficient nutrition plan and energy intake supervision, failure to form healthy eating habits and necessity to improve suitable training and competition ability supplement, etc; The combination of regulation and induction would help to improve the nutritional status of young football players. In the future, in-depth research can be carried out on the regional differences of nutritional imbalance, the comparison of nutritional status between young football players and adult football players, and the improvement of teenagers' self-awareness from a psychological perspective, so as to further solve the problem of nutritional imbalance of young football players.
The current situation, causes and solutions of the nutritional imbalance of young football players at home and abroad were summarized. It was pointed out that the imbalance of energy and material intake were mainly caused by insufficient total energy and carbohydrate intake and excessive protein and fat intake, with obvious regional characteristics; The main causes of nutritional imbalance were lack of nutrition knowledge, insufficient nutrition plan and energy intake supervision, failure to form healthy eating habits and necessity to improve suitable training and competition ability supplement, etc; The combination of regulation and induction would help to improve the nutritional status of young football players. In the future, in-depth research can be carried out on the regional differences of nutritional imbalance, the comparison of nutritional status between young football players and adult football players, and the improvement of teenagers' self-awareness from a psychological perspective, so as to further solve the problem of nutritional imbalance of young football players.
2022, 37(4)
:58-65.
doi: 10.12187/2022.04.008
Abstract:
Normal and slim cigarettes with different filter ventilation and cigarette paper air permeability were rolled. The effects of filter ventilation, cigarette paper ventilation and ventilation distribution on nine phenolic aroma components release from mainstream cigarette smoke were investigated. The results showed the filter ventilation rate, paper ventilation rate negatively correlated to the releases of nine phenolic aroma components in cigarette smoke, and with the increase of ventilation rate, the decrease rate of maltol with caramel flavour and smaller molecular weight was higher, while the decrease rate of eugenol with smoky flavor and larger molecular weight was lower. No matter normal or small cigarettes, the paper and filter ventilation rate have different effects on the decrease of smoke composition, and the paper ventilation rate has greater influence than the filter ventilation rate. The effects of filter ventilation rate, paper ventilation rate and ventilation distribution on the release of nine phenolic aroma components in conventional cigarette smoke were greater than those in slim cigarette smoke. When the total ventilation rate was the same, the release of 9 phenolic aroma components in cigarette smoke with high filter ventilation rate and low paper ventilation rate was higher than that with low filter ventilation rate and high paper ventilation rate.
Normal and slim cigarettes with different filter ventilation and cigarette paper air permeability were rolled. The effects of filter ventilation, cigarette paper ventilation and ventilation distribution on nine phenolic aroma components release from mainstream cigarette smoke were investigated. The results showed the filter ventilation rate, paper ventilation rate negatively correlated to the releases of nine phenolic aroma components in cigarette smoke, and with the increase of ventilation rate, the decrease rate of maltol with caramel flavour and smaller molecular weight was higher, while the decrease rate of eugenol with smoky flavor and larger molecular weight was lower. No matter normal or small cigarettes, the paper and filter ventilation rate have different effects on the decrease of smoke composition, and the paper ventilation rate has greater influence than the filter ventilation rate. The effects of filter ventilation rate, paper ventilation rate and ventilation distribution on the release of nine phenolic aroma components in conventional cigarette smoke were greater than those in slim cigarette smoke. When the total ventilation rate was the same, the release of 9 phenolic aroma components in cigarette smoke with high filter ventilation rate and low paper ventilation rate was higher than that with low filter ventilation rate and high paper ventilation rate.
2022, 37(4)
:66-72.
doi: 10.12187/2022.04.009
Abstract:
Waterborne coating materials were prepared by blending β-D-Glucose pentaacetate(GPA) and 5 kinds of viscous materials. The viscous material with the best effect was selected according to the viscosity, solid content and laboratory evaluation results, and the blending mass ratio was optimized. After that, the application evaluation of the best modified GPA waterborne coating material for cigarette was carried out. The results showed that PEG600 was the best viscous material and the material with m(GPA)∶m(PEG600)=1∶1 had the best laboratory comprehensive evaluation effect. And the use of coating material resulted in the increase of coating paper weight, filter weight and pressure drop, but the cigarette weight and draw resistance increased only a slight, while the changes of other parameters were very little. Besides, the total particulate matters and tar in the mainstream smoke of the coated cigarette were slightly lower than those of the uncoated cigarette, meanwhile, the nicotine release, moisture and puff number in the mainstream smoke of the coated cigarette were the same as those of the uncoated cigarette. Comparing with the uncoated cigarette, the phenol in the mainstream cigarette smoke of the coated cigarette reduced by 47.1%, and the other six harmful components all have a certain degree of reduction which was not large. Moreover, the sensory quality of the coated cigarette and the uncoated cigarette had no significant difference too.
Waterborne coating materials were prepared by blending β-D-Glucose pentaacetate(GPA) and 5 kinds of viscous materials. The viscous material with the best effect was selected according to the viscosity, solid content and laboratory evaluation results, and the blending mass ratio was optimized. After that, the application evaluation of the best modified GPA waterborne coating material for cigarette was carried out. The results showed that PEG600 was the best viscous material and the material with m(GPA)∶m(PEG600)=1∶1 had the best laboratory comprehensive evaluation effect. And the use of coating material resulted in the increase of coating paper weight, filter weight and pressure drop, but the cigarette weight and draw resistance increased only a slight, while the changes of other parameters were very little. Besides, the total particulate matters and tar in the mainstream smoke of the coated cigarette were slightly lower than those of the uncoated cigarette, meanwhile, the nicotine release, moisture and puff number in the mainstream smoke of the coated cigarette were the same as those of the uncoated cigarette. Comparing with the uncoated cigarette, the phenol in the mainstream cigarette smoke of the coated cigarette reduced by 47.1%, and the other six harmful components all have a certain degree of reduction which was not large. Moreover, the sensory quality of the coated cigarette and the uncoated cigarette had no significant difference too.
2022, 37(4)
:73-80.
doi: 10.12187/2022.04.010
Abstract:
With activated carbon filter cigarettes and ordinary filter cigarettes as the research objects, single factor experiment was used to determine the optimal extraction conditions of aroma components in activated carbon particles and tow. The aroma components in the cigarette butts and mainstream cigarette smoke were detected, the differences in the aroma components in the two cigarettes were compared, and the retention law of the aroma components in the mainstream cigarette smoke by the activated carbon filter was analyzed. The results showed that the optimal extraction conditions for activated carbon particles were dichloromethane as the extraction solvent, the extraction volume was 25 mL, the extraction time was 25 min, and the extraction temperature was 25 ℃. The optimal extraction conditions for the tow were ethanol as the extraction solvent, the extraction volume was 50 mL, the extraction time was 35 min, and the extraction temperature was 30 ℃. The aroma components retained by activated carbon particles were mostly small molecular substances. In general, the ability of activated carbon filter to intercept aroma components was weaker than that of ordinary filters, and the total content of aroma components in mainstream smoke particles of activated carbon filter cigarettes was higher than that of ordinary filter cigarettes. The retention rate of activated carbon filter to most substances in mainstream cigarette smoke was lower than that of ordinary filters, and the retention rate of macromolecular substances was significantly different.
With activated carbon filter cigarettes and ordinary filter cigarettes as the research objects, single factor experiment was used to determine the optimal extraction conditions of aroma components in activated carbon particles and tow. The aroma components in the cigarette butts and mainstream cigarette smoke were detected, the differences in the aroma components in the two cigarettes were compared, and the retention law of the aroma components in the mainstream cigarette smoke by the activated carbon filter was analyzed. The results showed that the optimal extraction conditions for activated carbon particles were dichloromethane as the extraction solvent, the extraction volume was 25 mL, the extraction time was 25 min, and the extraction temperature was 25 ℃. The optimal extraction conditions for the tow were ethanol as the extraction solvent, the extraction volume was 50 mL, the extraction time was 35 min, and the extraction temperature was 30 ℃. The aroma components retained by activated carbon particles were mostly small molecular substances. In general, the ability of activated carbon filter to intercept aroma components was weaker than that of ordinary filters, and the total content of aroma components in mainstream smoke particles of activated carbon filter cigarettes was higher than that of ordinary filter cigarettes. The retention rate of activated carbon filter to most substances in mainstream cigarette smoke was lower than that of ordinary filters, and the retention rate of macromolecular substances was significantly different.
2022, 37(4)
:81-85,93.
doi: 10.12187/2022.04.011
Abstract:
Under the condition of the same cavity depth, four circular cavity combined filter rods with different cavity diameter were designed, and the influence of cavity diameter on the main physical and chemical indexes and sensory quality of cigarettes was studied. The results showed as follows: the release amounts of total particulate matter, tar and nicotine of circular cavity combined filter cigarettes increased with the increase of cavity diameter, and were higher than those of cigarettes with ordinary cellulose acetate filters. The nicotine interception in ordinary tow segment had little change, while the nicotine interception in the tow segment of the cavity filter rod and the nicotine interception per unit area gradually decreased with the increase of the cavity diameter. With the increase of cavity diameter, the hazard index of combined filter cigarettes increased, and the offset of cigarette hazard index gradually increased. The sensory quality evaluation score of combined filter cigarettes decreased with the increase of the cavity diameter.
Under the condition of the same cavity depth, four circular cavity combined filter rods with different cavity diameter were designed, and the influence of cavity diameter on the main physical and chemical indexes and sensory quality of cigarettes was studied. The results showed as follows: the release amounts of total particulate matter, tar and nicotine of circular cavity combined filter cigarettes increased with the increase of cavity diameter, and were higher than those of cigarettes with ordinary cellulose acetate filters. The nicotine interception in ordinary tow segment had little change, while the nicotine interception in the tow segment of the cavity filter rod and the nicotine interception per unit area gradually decreased with the increase of the cavity diameter. With the increase of cavity diameter, the hazard index of combined filter cigarettes increased, and the offset of cigarette hazard index gradually increased. The sensory quality evaluation score of combined filter cigarettes decreased with the increase of the cavity diameter.
2022, 37(4)
:86-93.
doi: 10.12187/2022.04.012
Abstract:
The strains that could degrade β-carotene with high efficiency were screened from fresh Yuyan 13 tobacco leaves, and the main degradation products were detected by GC-MS, the species of the strain were identified by morphology and 16S rDNA phylogenetic tree, the fermentation conditions of the strain were optimized by single factor test and orthogonal test. The results showed that YT-3 strain was Enterobacter hormanii subsp.which could degrade β-carotene with high efficiency. The main degradation products were β-ionone, dihydrokiwifruit lactone, β-cyclic citral (3.21%) and other flavor substances. The optimum fermentation conditions of YT-3 strain were as follows: NaNO3 concentration 4 g/L, sucrose concentration 30 g/L, yeast powder concentration 3 g/L, initial pH value 7.0. Under these fermentation conditions, the degradation rate of β-carotene reached 97.05%.
The strains that could degrade β-carotene with high efficiency were screened from fresh Yuyan 13 tobacco leaves, and the main degradation products were detected by GC-MS, the species of the strain were identified by morphology and 16S rDNA phylogenetic tree, the fermentation conditions of the strain were optimized by single factor test and orthogonal test. The results showed that YT-3 strain was Enterobacter hormanii subsp.which could degrade β-carotene with high efficiency. The main degradation products were β-ionone, dihydrokiwifruit lactone, β-cyclic citral (3.21%) and other flavor substances. The optimum fermentation conditions of YT-3 strain were as follows: NaNO3 concentration 4 g/L, sucrose concentration 30 g/L, yeast powder concentration 3 g/L, initial pH value 7.0. Under these fermentation conditions, the degradation rate of β-carotene reached 97.05%.
2022, 37(4)
:94-99.
doi: 10.12187/2022.04.013
Abstract:
In order to improve the accuracy of near-infrared prediction under limited sample conditions, a prediction method of the geographical origin of flue-cured tobacco strips based on cascade classification was proposed. In this method, the flavor attributes of samples were judged by near-infrared spectroscopy, and the flavor model was constructed as the middle layer, and then the origin model was constructed by LDA or PLS method under a single flavor framework to predict the geographical origin. The redried tobacco in the main producing area in China was taken as the objects in the experiment. The results showed that by introducing the flavor model as the middle layer, the accuracy of the classification model based on LDA was improved from 83.33% to 94.44%; the accuracy of PLS based classification model increased from 72.22% to 86.11%. Under the condition of limited sample data and without introducing new model parameters, this method could effectively reduce the proportion of misjudgment of the origin of redried tobacco.
In order to improve the accuracy of near-infrared prediction under limited sample conditions, a prediction method of the geographical origin of flue-cured tobacco strips based on cascade classification was proposed. In this method, the flavor attributes of samples were judged by near-infrared spectroscopy, and the flavor model was constructed as the middle layer, and then the origin model was constructed by LDA or PLS method under a single flavor framework to predict the geographical origin. The redried tobacco in the main producing area in China was taken as the objects in the experiment. The results showed that by introducing the flavor model as the middle layer, the accuracy of the classification model based on LDA was improved from 83.33% to 94.44%; the accuracy of PLS based classification model increased from 72.22% to 86.11%. Under the condition of limited sample data and without introducing new model parameters, this method could effectively reduce the proportion of misjudgment of the origin of redried tobacco.
2022, 37(4)
:100-110.
doi: 10.12187/2022.04.014
Abstract:
Based on the domestic and foreign research results of marine waste biomass resource treatment, the adsorption materials can be divided into four categories according to the difficulty of preparation—directly used marine biomass adsorbing materials, marine biomass modified adsorbing materials, biochar made from marine biomass and highly-added value adsorbing materials made from biomass. The adsorption capacity and kinetics of biomass-based adsorption materials were improved obviously after modification and further treatment. It was expected that more types of marine waste biomass could be explored to find a more suitable adsorbent for different heavy metal ions, and efforts could be made to recycle waste biomass in the future.
Based on the domestic and foreign research results of marine waste biomass resource treatment, the adsorption materials can be divided into four categories according to the difficulty of preparation—directly used marine biomass adsorbing materials, marine biomass modified adsorbing materials, biochar made from marine biomass and highly-added value adsorbing materials made from biomass. The adsorption capacity and kinetics of biomass-based adsorption materials were improved obviously after modification and further treatment. It was expected that more types of marine waste biomass could be explored to find a more suitable adsorbent for different heavy metal ions, and efforts could be made to recycle waste biomass in the future.
2022, 37(4)
:111-117.
doi: 10.12187/2022.04.015
Abstract:
To investigate the effects of exogenous melatonin on the growth physiology and Cd content of wheat seedling under Cd stress, the present research selected wheat seed Aikang No.58 as test material and adopted indoor culture method to study the effects of different concentrations exogenous melatonin under the stress of different Cd concentrations on the growth, physiological characteristics, and Cd absorption of wheat seedling. Results showed that under Cd stress, the addition of exogenous melatonin promoted the growth of wheat seedling to some extent. With the increase of melatonin concentration, the activities of peroxidase, catalase, and superoxide dismutase in wheat shoot tended to increase first and then decrease, while the content of malondialdehyde decreased under low concentration of Cd stress and increased under high concentration of Cd stress. Exogenous melatonin significantly decreased the Cd content in wheat root and shoot to some extent. Moreover, when the Cd concentration was 100 μmol·L-1, the transfer coefficient of Cd in wheat seeding increased significantly, which indicated that exogenous melatonin not only reduced Cd absorption in wheat seeding, but also promoted Cd transfer in wheat seeding to some extent. However, when the Cd concentration increased, the higher concentration of melatonin had no significant effect on the transfer of Cd in wheat seeding.
To investigate the effects of exogenous melatonin on the growth physiology and Cd content of wheat seedling under Cd stress, the present research selected wheat seed Aikang No.58 as test material and adopted indoor culture method to study the effects of different concentrations exogenous melatonin under the stress of different Cd concentrations on the growth, physiological characteristics, and Cd absorption of wheat seedling. Results showed that under Cd stress, the addition of exogenous melatonin promoted the growth of wheat seedling to some extent. With the increase of melatonin concentration, the activities of peroxidase, catalase, and superoxide dismutase in wheat shoot tended to increase first and then decrease, while the content of malondialdehyde decreased under low concentration of Cd stress and increased under high concentration of Cd stress. Exogenous melatonin significantly decreased the Cd content in wheat root and shoot to some extent. Moreover, when the Cd concentration was 100 μmol·L-1, the transfer coefficient of Cd in wheat seeding increased significantly, which indicated that exogenous melatonin not only reduced Cd absorption in wheat seeding, but also promoted Cd transfer in wheat seeding to some extent. However, when the Cd concentration increased, the higher concentration of melatonin had no significant effect on the transfer of Cd in wheat seeding.
2022, 37(4)
:118-126.
doi: 10.12187/2022.04.016
Abstract:
Concentrations of 8 heavy metals (Cd, Cr, As, Pb, Zn, Mn, Cu, Ni) in soils from the living quarters of four various administrative districts of Kunming were determined. Pollution levels and ecological & health risk were assessed by index of geo-accumulation (Igeo), the potential ecological risk index (RI) and human health risk assessment in the study. Results showed that all heavy metals except Cr and Ni exceeded their background values. All of the samples’ heavy mental concentrations were lower than the risk screening values for concentration of development land in the national soil environment quality standards(GB 36600—2018). The index of geo-accumulation (Igeo) data showed Zn>Cd>Cu>Mn>Pb>Ni>As>Cr, and the pollution of Zn and Cd reached the moderate levels. Potential ecological risk index (RI) results showed Cd>Ni>Cu>As>Pb>Mn>Cr>Zn, in which Cd had a strong potential ecological risk, indicating a strong ecological risk, the comprehensive ecological risk index of the study area reached the medium ecological risk level. The non-carcinogenic risk HI of soil heavy metals in Kunming City for adults and children were lower than 1, and the non-carcinogenic risk of children was higher than that of adults; the carcinogenic risk to children and adults was within the acceptable range for humans. However, since the current health risk model lacked reference values for carcinogenic slope factors for hand-to-mouth intake and skin contact, it might underestimate the actual carcinogenic risk of heavy metals in the soil.
Concentrations of 8 heavy metals (Cd, Cr, As, Pb, Zn, Mn, Cu, Ni) in soils from the living quarters of four various administrative districts of Kunming were determined. Pollution levels and ecological & health risk were assessed by index of geo-accumulation (Igeo), the potential ecological risk index (RI) and human health risk assessment in the study. Results showed that all heavy metals except Cr and Ni exceeded their background values. All of the samples’ heavy mental concentrations were lower than the risk screening values for concentration of development land in the national soil environment quality standards(GB 36600—2018). The index of geo-accumulation (Igeo) data showed Zn>Cd>Cu>Mn>Pb>Ni>As>Cr, and the pollution of Zn and Cd reached the moderate levels. Potential ecological risk index (RI) results showed Cd>Ni>Cu>As>Pb>Mn>Cr>Zn, in which Cd had a strong potential ecological risk, indicating a strong ecological risk, the comprehensive ecological risk index of the study area reached the medium ecological risk level. The non-carcinogenic risk HI of soil heavy metals in Kunming City for adults and children were lower than 1, and the non-carcinogenic risk of children was higher than that of adults; the carcinogenic risk to children and adults was within the acceptable range for humans. However, since the current health risk model lacked reference values for carcinogenic slope factors for hand-to-mouth intake and skin contact, it might underestimate the actual carcinogenic risk of heavy metals in the soil.
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
Address：136 Science Avenue, Zhengzhou City, Henan Province, China
Postal Code：450001
Tel：(086)0371-86608635
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