Most downloaded articles
2022(9):114-119.
DOI: 10.13652/j.spjx.1003.5788.2022.90122
Abstract:
Objective: Analyzed the workspace of 6-DOF food handling robot and planed the motion trajectory, so as to provide basis for the layout of food handling platform in workstation and the motion control of robot. Methods: Composition and structure of the robot were analyzed, the kinematics model was established, and the kinematics model was verified by MATLAB. Based on this, the workspace of the robot was modeled and solved, the working area of the robot was obtained, and the reasonable layout position of the food handling table was given; combined with the requirements of food handling task, a three-stage quintic polynomial interpolation method was proposed for robot end trajectory planning. The effectiveness of this method was verified by MATLAB simulation and experiment. Results: The reasonable layout space of the food handling table was the area of z＞0 mm and 200 mm＜r＜500 mm. The method of three-stage quintic polynomial trajectory planning can make the robot perform the food handling task smoothly, and increase the accurate control of the point position, speed and acceleration of the robot. Conclusion: The method of three-stage quintic polynomial trajectory planning is effective for the robot to perform the food handling task.
Objective: Analyzed the workspace of 6-DOF food handling robot and planed the motion trajectory, so as to provide basis for the layout of food handling platform in workstation and the motion control of robot. Methods: Composition and structure of the robot were analyzed, the kinematics model was established, and the kinematics model was verified by MATLAB. Based on this, the workspace of the robot was modeled and solved, the working area of the robot was obtained, and the reasonable layout position of the food handling table was given; combined with the requirements of food handling task, a three-stage quintic polynomial interpolation method was proposed for robot end trajectory planning. The effectiveness of this method was verified by MATLAB simulation and experiment. Results: The reasonable layout space of the food handling table was the area of z＞0 mm and 200 mm＜r＜500 mm. The method of three-stage quintic polynomial trajectory planning can make the robot perform the food handling task smoothly, and increase the accurate control of the point position, speed and acceleration of the robot. Conclusion: The method of three-stage quintic polynomial trajectory planning is effective for the robot to perform the food handling task.
2026, 42(7):1-10.
DOI: 10.13652/j.spjx.1003.5788.2025.80644
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Objective To investigate the aroma changes of sauce-flavored Baijiu during different aging periods, and to provide a theoretical basis for Baijiu aroma analysis and modern processing technology research.Methods Electronic nose, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS) were employed. Sauce-flavored Baijiu with different aging times (original liquor, 1-year aged, and 5-year aged) was used as the research objects. Combined with multivariate statistical methods, including principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), the differences in volatile flavor compounds of Baijiu with different aging times were analyzed.Results A total of 1 626 volatile compounds were detected in the three Baijiu samples. Based on the calculation of relative odor activity value (rOAV) and screening of compounds with rOAV≥1, 47 important volatile compounds were identified, including 1 amine, 6 alcohols, 2 aromatic hydrocarbons, 1 phenol, 1 halogenated hydrocarbon, 3 ethers, 10 aldehydes, 3 terpenoids, 5 ketones, 3 heterocyclic compounds, and 12 esters.Conclusion The aroma characteristics of Baijiu with different aging times are similar, but clear differences also exist. With increasing aging time, the contents of higher alcohols, aldehydes, and esters-contributing to a rich and delicate flavor-increase, while pungent and irritating substances decrease. As a result, the aroma of Baijiu becomes more stable and mellow, with a more complex aroma profile.
Objective To investigate the aroma changes of sauce-flavored Baijiu during different aging periods, and to provide a theoretical basis for Baijiu aroma analysis and modern processing technology research.Methods Electronic nose, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS) were employed. Sauce-flavored Baijiu with different aging times (original liquor, 1-year aged, and 5-year aged) was used as the research objects. Combined with multivariate statistical methods, including principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), the differences in volatile flavor compounds of Baijiu with different aging times were analyzed.Results A total of 1 626 volatile compounds were detected in the three Baijiu samples. Based on the calculation of relative odor activity value (rOAV) and screening of compounds with rOAV≥1, 47 important volatile compounds were identified, including 1 amine, 6 alcohols, 2 aromatic hydrocarbons, 1 phenol, 1 halogenated hydrocarbon, 3 ethers, 10 aldehydes, 3 terpenoids, 5 ketones, 3 heterocyclic compounds, and 12 esters.Conclusion The aroma characteristics of Baijiu with different aging times are similar, but clear differences also exist. With increasing aging time, the contents of higher alcohols, aldehydes, and esters-contributing to a rich and delicate flavor-increase, while pungent and irritating substances decrease. As a result, the aroma of Baijiu becomes more stable and mellow, with a more complex aroma profile.
2026, 42(7):11-17.
DOI: 10.13652/j.spjx.1003.5788.2025.80586
Abstract:
Objective To comprehensively reveal the flavor and quality characteristics, and differences of Morchella esculenta under different cultivation methods, and systematically evaluate their volatile aroma components.Methods Qualitative and quantitative analyses are conducted on volatile aroma components in M. esculenta cultivated in greenhouses, under forests, and in caves in the vicinity of FAST by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) techniques. The contribution of different components to the overall flavor is assessed by the relative odor activity value (ROAV) method. Based on this, principal component analysis and cluster analysis are conducted, achieving a comprehensive evaluation of the flavor characteristics of M. esculenta.Results The GC-MS analysis results show that 1 201 volatile substances are detected in M. esculenta under the three cultivation methods, mainly including acid, alcohol, aldehyde, amine, aromatics, ester, ether, halogenated hydrocarbons, heterocyclic compounds, hydrocarbons, ketone, nitrogen compounds, phenol, sulfur compounds, and terpenoids. Among them, the relative content of heterocyclic compounds is the highest, ranging from 11.042% to 28.365%, followed by ester and aldehyde. Due to different cultivation methods, the relative content of various volatile components varies, with significant differences between most of them (P<0.05). The analysis results of the ROAV method show that the main volatile aroma components in M. esculenta under three cultivation methods are α,α,4-trimethyl-3-cyclohexene-1-methylthiol, dihydro-2-methyl-3(2H)-furanone, 5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone, and 1-nonen-3-one. Different cultivation methods result in variations in the volatile aroma components in various M. esculenta. The comprehensive evaluation results of principal component analysis and cluster analysis indicate that the cave cultivation method leads to the highest comprehensive score on the aroma quality of M. esculenta and the best aroma quality.Conclusion There are numerous types of volatile compounds in M. esculenta cultivated in greenhouses, under forests, and in caves in the vicinity of FAST, with significant differences in relative content. The main volatile aroma components vary with the cultivation method. Additionally, the best aroma quality is found in M. esculenta cultivated in caves.
Objective To comprehensively reveal the flavor and quality characteristics, and differences of Morchella esculenta under different cultivation methods, and systematically evaluate their volatile aroma components.Methods Qualitative and quantitative analyses are conducted on volatile aroma components in M. esculenta cultivated in greenhouses, under forests, and in caves in the vicinity of FAST by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) techniques. The contribution of different components to the overall flavor is assessed by the relative odor activity value (ROAV) method. Based on this, principal component analysis and cluster analysis are conducted, achieving a comprehensive evaluation of the flavor characteristics of M. esculenta.Results The GC-MS analysis results show that 1 201 volatile substances are detected in M. esculenta under the three cultivation methods, mainly including acid, alcohol, aldehyde, amine, aromatics, ester, ether, halogenated hydrocarbons, heterocyclic compounds, hydrocarbons, ketone, nitrogen compounds, phenol, sulfur compounds, and terpenoids. Among them, the relative content of heterocyclic compounds is the highest, ranging from 11.042% to 28.365%, followed by ester and aldehyde. Due to different cultivation methods, the relative content of various volatile components varies, with significant differences between most of them (P<0.05). The analysis results of the ROAV method show that the main volatile aroma components in M. esculenta under three cultivation methods are α,α,4-trimethyl-3-cyclohexene-1-methylthiol, dihydro-2-methyl-3(2H)-furanone, 5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone, and 1-nonen-3-one. Different cultivation methods result in variations in the volatile aroma components in various M. esculenta. The comprehensive evaluation results of principal component analysis and cluster analysis indicate that the cave cultivation method leads to the highest comprehensive score on the aroma quality of M. esculenta and the best aroma quality.Conclusion There are numerous types of volatile compounds in M. esculenta cultivated in greenhouses, under forests, and in caves in the vicinity of FAST, with significant differences in relative content. The main volatile aroma components vary with the cultivation method. Additionally, the best aroma quality is found in M. esculenta cultivated in caves.
4 Determination of six human milk oligosaccharides in infant formula milk powder by ion chromatography
2025, 41(5):64-70.
DOI: 10.13652/j.spjx.1003.5788.2024.80913
Abstract:
Objective To establish an ion chromatography method for the simultaneous determination of six human milk oligosaccharides (HMOs) in infant formula powder.Methods The samples were enzymatically hydrolyzed using fructanase. Gradient elution was performed with a mobile phase consisting of water, 0.5 mol/L sodium hydroxide, and 0.3 mol/L sodium acetate. Separation was carried out on a Thermo Fisher CarboPac? PA1 Analytical Column, and detection was performed using ion chromatography with pulsed amperometric detection.Results In milk powder, 2'-fucosyllactose (2'-FL), 3-fucosyllactose (3-FL), and lacto-N-tetraose (LNT) showed good linearity within the range of 1~100 mg/L, while lacto-N-neotetraose (LNnT), 3'-sialyllactose (3'-SL), and 6'-sialyllactose (6'-SL) exhibited good linearity in the range of 0.5~50.0 mg/L, with correlation coefficients all greater than 0.999. The limit of detection (LOD) for 2'-FL, LNnT, 3-FL, and LNT was 10 mg/100 g, and the limit of quantification (LOQ) was 30 mg/100 g. The LOD for 3'-SL and 6'-SL was 5 mg/100 g, and the LOQ was 15 mg/100 g. The average recoveries of the six HMOs at low, medium, and high concentrations ranged from 98.0% to 101.0%, with relative standard deviations (RSDs) between 0.3% and 2.4%. In actual sample analysis, when the content of the six HMOs ranged from 0.1 to 10.0 g/kg, the RSDs were 0.5% to 9.4%. When the content ranged from 10 to 100 g/kg, the RSDs were 1.4% to 4.0%.Conclusion The proposed method meets the requirements for routine analysis and is suitable for the determination of six HMOs in various infant formula powders containing HMOs.
Objective To establish an ion chromatography method for the simultaneous determination of six human milk oligosaccharides (HMOs) in infant formula powder.Methods The samples were enzymatically hydrolyzed using fructanase. Gradient elution was performed with a mobile phase consisting of water, 0.5 mol/L sodium hydroxide, and 0.3 mol/L sodium acetate. Separation was carried out on a Thermo Fisher CarboPac? PA1 Analytical Column, and detection was performed using ion chromatography with pulsed amperometric detection.Results In milk powder, 2'-fucosyllactose (2'-FL), 3-fucosyllactose (3-FL), and lacto-N-tetraose (LNT) showed good linearity within the range of 1~100 mg/L, while lacto-N-neotetraose (LNnT), 3'-sialyllactose (3'-SL), and 6'-sialyllactose (6'-SL) exhibited good linearity in the range of 0.5~50.0 mg/L, with correlation coefficients all greater than 0.999. The limit of detection (LOD) for 2'-FL, LNnT, 3-FL, and LNT was 10 mg/100 g, and the limit of quantification (LOQ) was 30 mg/100 g. The LOD for 3'-SL and 6'-SL was 5 mg/100 g, and the LOQ was 15 mg/100 g. The average recoveries of the six HMOs at low, medium, and high concentrations ranged from 98.0% to 101.0%, with relative standard deviations (RSDs) between 0.3% and 2.4%. In actual sample analysis, when the content of the six HMOs ranged from 0.1 to 10.0 g/kg, the RSDs were 0.5% to 9.4%. When the content ranged from 10 to 100 g/kg, the RSDs were 1.4% to 4.0%.Conclusion The proposed method meets the requirements for routine analysis and is suitable for the determination of six HMOs in various infant formula powders containing HMOs.
2024, 40(10):156-161.
DOI: 10.13652/j.spjx.1003.5788.2024.60077
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［［Objective ］］ This study investigated the in vitro fermentation characteristics and gut microbiota modulation effects of polysaccharides extracted from mulberries at different maturity stages.［［Methods ］］ Polysaccharides from green,red and purple mulberries were subjected to in vitro fermentation using human fecal microbiota.Changes in pH values,short -chain fatty acids (SCFA ) levels and substrate composition were monitored.Gut microbiota composition was analyzed through 16S rDNA sequencing.［［Results］］ Polysaccharides from all three mulberry types were effectively degraded and utilized during fermentation,generating significant levels of SCFAs,including acetic acid,propionic acid,and butyric acid.Purple and red mulberry polysaccharides demonstrated a superior capacity for SCFA production compared to those from green mulberries.Additionally,they selectively modulated gut microbiota,promoting the growth of beneficial bacteria such as Bacteroides,Parabacteroides,and Phascolarctobacterium,while suppressing harmful bacteria like Fusobacterium.［［Conclusion ］］ Polysaccharides derived from mulberries at three different maturity stages exhibit notable prebiotic activity by enhancing beneficial metabolic products and positively influencing gut microbiota composition.Fully ripe purple mulberries exhibited the most pronounced effects,suggesting their potential as a superior source of functional ingredients.
［［Objective ］］ This study investigated the in vitro fermentation characteristics and gut microbiota modulation effects of polysaccharides extracted from mulberries at different maturity stages.［［Methods ］］ Polysaccharides from green,red and purple mulberries were subjected to in vitro fermentation using human fecal microbiota.Changes in pH values,short -chain fatty acids (SCFA ) levels and substrate composition were monitored.Gut microbiota composition was analyzed through 16S rDNA sequencing.［［Results］］ Polysaccharides from all three mulberry types were effectively degraded and utilized during fermentation,generating significant levels of SCFAs,including acetic acid,propionic acid,and butyric acid.Purple and red mulberry polysaccharides demonstrated a superior capacity for SCFA production compared to those from green mulberries.Additionally,they selectively modulated gut microbiota,promoting the growth of beneficial bacteria such as Bacteroides,Parabacteroides,and Phascolarctobacterium,while suppressing harmful bacteria like Fusobacterium.［［Conclusion ］］ Polysaccharides derived from mulberries at three different maturity stages exhibit notable prebiotic activity by enhancing beneficial metabolic products and positively influencing gut microbiota composition.Fully ripe purple mulberries exhibited the most pronounced effects,suggesting their potential as a superior source of functional ingredients.
2023, 39(11):7-11.
DOI: 10.13652/j.spjx.1003.5788.2023.80390
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The policy evolution, standard rules, supporting measures and implementation effects of the nutri-grade labeling in Singapore were summarized based on collected materials about Nutri-Grade labeling from the official website of Singapore Ministry of Health and literatures. The practical experience of nutri-grade labeling in mandatory disclosure of sugar information in nutrition information, evaluation of multi-form sugar-sweetened beverages, and prohibition of advertising of high-sugar beverages has important implications for the implementation of mandatory FOP labeling of sugar-sweetened beverages in China.
The policy evolution, standard rules, supporting measures and implementation effects of the nutri-grade labeling in Singapore were summarized based on collected materials about Nutri-Grade labeling from the official website of Singapore Ministry of Health and literatures. The practical experience of nutri-grade labeling in mandatory disclosure of sugar information in nutrition information, evaluation of multi-form sugar-sweetened beverages, and prohibition of advertising of high-sugar beverages has important implications for the implementation of mandatory FOP labeling of sugar-sweetened beverages in China.
2022(1):55-58.
DOI: 10.13652/j.issn.1003-5788.2022.01.008
Abstract:
Objective:This study focuses on improving the comprehensive utilization rate of Polygonatum cyrtonema.Methods:The contents of total flavonoids, total saponins and total phenols from roots, stems, leaves, flowers and buds, of P. cyrtonema were determined. The scavenging rates of DPPH·, ·OH and nitrites in extracts of above tissue were measured and compared as well. Results:The contents of total flavonoids and total phenols five different kinds of non-medicinal tissue were in the same order, in which from highest to lowest was, leaves, buds, flowers, stems and roots, and the content of total saponins in flower was the highest In terms of antioxidant activity, the DPPH ·, ·OH and nitrite scavenging rate of leaf extract were the highest, followed by buds and flowers. Correlation analysis showed that the clearance of DPPH ·, · OH and nitrite by the extract from different tissue showed a certain positive correlation with the contents of total flavonoids, total saponins and total phenols. Conclusion:The extract of non-medicinal parts of P. cyrtonema has good biological activity.
Objective:This study focuses on improving the comprehensive utilization rate of Polygonatum cyrtonema.Methods:The contents of total flavonoids, total saponins and total phenols from roots, stems, leaves, flowers and buds, of P. cyrtonema were determined. The scavenging rates of DPPH·, ·OH and nitrites in extracts of above tissue were measured and compared as well. Results:The contents of total flavonoids and total phenols five different kinds of non-medicinal tissue were in the same order, in which from highest to lowest was, leaves, buds, flowers, stems and roots, and the content of total saponins in flower was the highest In terms of antioxidant activity, the DPPH ·, ·OH and nitrite scavenging rate of leaf extract were the highest, followed by buds and flowers. Correlation analysis showed that the clearance of DPPH ·, · OH and nitrite by the extract from different tissue showed a certain positive correlation with the contents of total flavonoids, total saponins and total phenols. Conclusion:The extract of non-medicinal parts of P. cyrtonema has good biological activity.
2022(6):1-4.
DOI: 10.13652/j.spjx.1003.5788.2022.60030
Abstract:
Based on the scientific theory of modern nutrition and functional food science, this paper uses biotechnology and information digital technology to establish a more precise, flexible, integrated and digital functional food research and development system-flexible precise nutrition intervention system (FPNIS) which improves the shortcomings of the two common functional food research and development models that are based on traditional Chinese herbal medicines or simple ingredient dietary supplements. Through the establishment of FPNIS, provide a new way to explore the research and development of efficient and precise functional food, and analyze its trend.
Based on the scientific theory of modern nutrition and functional food science, this paper uses biotechnology and information digital technology to establish a more precise, flexible, integrated and digital functional food research and development system-flexible precise nutrition intervention system (FPNIS) which improves the shortcomings of the two common functional food research and development models that are based on traditional Chinese herbal medicines or simple ingredient dietary supplements. Through the establishment of FPNIS, provide a new way to explore the research and development of efficient and precise functional food, and analyze its trend.
2025, 41(11):9-20.
DOI: 10.13652/j.spjx.1003.5788.2025.60126
Abstract:
Objective This study aimed to investigate the functional characteristics of polyphenols from black soybean hulls (a by-product of black soybean) and their application in bread.Methods The polyphenol extracts were obtained from black soybean hulls via ultrasonic-assisted solvent extraction, followed by the isolation of free and bound polyphenols. The regulatory effect of these polyphenols on the starch digestion characteristics of bread was further analyzed.Results Free and bound polyphenols were isolated from polyphenols from black soybean hulls, with contents of 20.42 mg GAE/g and 9.47 mg GAE/g, respectively. The ABTS and DPPH radical scavenging rates of free polyphenols reached 88.85% and 80.04%, respectively. The addition of 0.25% polyphenol extracts decreased the rapidly digestible starch content in bread crumb and crust from 43.75% and 40.23% to 31.25% and 27.93%, respectively, while the resistant starch content increased to 45.32% and 50.59%, respectively. Molecular docking analysis revealed that components such as chlorogenic acid in polyphenols from black soybean hulls exerted competitive and noncompetitive mixed inhibition on α-glucosidase through hydrogen bonding and hydrophobic interactions.Conclusion Polyphenols from black soybean hulls can retard bread digestion by inhibiting α-glucosidase activity and modifying starch structure.
Objective This study aimed to investigate the functional characteristics of polyphenols from black soybean hulls (a by-product of black soybean) and their application in bread.Methods The polyphenol extracts were obtained from black soybean hulls via ultrasonic-assisted solvent extraction, followed by the isolation of free and bound polyphenols. The regulatory effect of these polyphenols on the starch digestion characteristics of bread was further analyzed.Results Free and bound polyphenols were isolated from polyphenols from black soybean hulls, with contents of 20.42 mg GAE/g and 9.47 mg GAE/g, respectively. The ABTS and DPPH radical scavenging rates of free polyphenols reached 88.85% and 80.04%, respectively. The addition of 0.25% polyphenol extracts decreased the rapidly digestible starch content in bread crumb and crust from 43.75% and 40.23% to 31.25% and 27.93%, respectively, while the resistant starch content increased to 45.32% and 50.59%, respectively. Molecular docking analysis revealed that components such as chlorogenic acid in polyphenols from black soybean hulls exerted competitive and noncompetitive mixed inhibition on α-glucosidase through hydrogen bonding and hydrophobic interactions.Conclusion Polyphenols from black soybean hulls can retard bread digestion by inhibiting α-glucosidase activity and modifying starch structure.
2024, 41(2):9-20,27.
DOI: 10.13652/j.spjx.1003.5788.2023.81159
Abstract:
Microfluidic chips are driven by microfluidic pumps and controlled by microfluidic valves in microfluidic systems to achieve accurate manipulation of microfluidics. With the continuous improvement of microfluidic chip integration, liquid channels have become more complex and have smaller volumes. How to achieve fluid drive and control at the micro scale has become a key focus in chip design. The paper elaborates on the current research status, key technologies, and development trends of micro pumps and micro valves both domestically and internationally, aiming to provide reference and guidance for the development of related industries and technological research.
Microfluidic chips are driven by microfluidic pumps and controlled by microfluidic valves in microfluidic systems to achieve accurate manipulation of microfluidics. With the continuous improvement of microfluidic chip integration, liquid channels have become more complex and have smaller volumes. How to achieve fluid drive and control at the micro scale has become a key focus in chip design. The paper elaborates on the current research status, key technologies, and development trends of micro pumps and micro valves both domestically and internationally, aiming to provide reference and guidance for the development of related industries and technological research.
2025, 41(11):1-8.
DOI: 10.13652/j.spjx.1003.5788.2025.80437
Abstract:
Objective To obtain recombinant tropomyosin (TM).Methods In this study, the gene sequence of a TM homologous protein is obtained from the National Center of Biotechnology Information (NCBI) database, and specific primers are designed accordingly. Subsequently, using the cDNA of Litopenaeus vannamei meat as the template, the TM coding gene sequence of L. vannamei is amplified by PCR and sequenced. Finally, the prokaryotic recombinant expression system for L. vannamei TM is established using the Escherichia coli heterologous recombinant expression vector pET29a.Results After agarose gel electrophoresis (AGE) of the RNA samples, the band is clear and bright, with no diffusion observed in the lanes. The cDNA sample displays a clear band around 300 bp, indicating successful extraction of the total RNA samples from L. vannamei meat with intact structures and subsequent reverse transcription into cDNA. The PCR results indicate a single band at 900 bp for the TM coding gene of L. vannamei. BLAST analysis of the gene sequence shows that the TM coding gene is highly homologous (99.77%) to the known TM coding gene of L. vannamei. This study further constructs the TM recombinant expression vector pET29a-TM. SDS-PAGE analysis confirms efficient expression of the target protein in the host strain, yielding a soluble recombinant TM protein band with a relative molecular weight of approximately 3.7×104.Conclusion This study successfully clones the TM coding gene from L. vannamei and constructs its prokaryotic expression system, enabling the efficient production of soluble recombinant TM protein.
Objective To obtain recombinant tropomyosin (TM).Methods In this study, the gene sequence of a TM homologous protein is obtained from the National Center of Biotechnology Information (NCBI) database, and specific primers are designed accordingly. Subsequently, using the cDNA of Litopenaeus vannamei meat as the template, the TM coding gene sequence of L. vannamei is amplified by PCR and sequenced. Finally, the prokaryotic recombinant expression system for L. vannamei TM is established using the Escherichia coli heterologous recombinant expression vector pET29a.Results After agarose gel electrophoresis (AGE) of the RNA samples, the band is clear and bright, with no diffusion observed in the lanes. The cDNA sample displays a clear band around 300 bp, indicating successful extraction of the total RNA samples from L. vannamei meat with intact structures and subsequent reverse transcription into cDNA. The PCR results indicate a single band at 900 bp for the TM coding gene of L. vannamei. BLAST analysis of the gene sequence shows that the TM coding gene is highly homologous (99.77%) to the known TM coding gene of L. vannamei. This study further constructs the TM recombinant expression vector pET29a-TM. SDS-PAGE analysis confirms efficient expression of the target protein in the host strain, yielding a soluble recombinant TM protein band with a relative molecular weight of approximately 3.7×104.Conclusion This study successfully clones the TM coding gene from L. vannamei and constructs its prokaryotic expression system, enabling the efficient production of soluble recombinant TM protein.
2025, 41(11):35-40.
DOI: 10.13652/j.spjx.1003.5788.2025.80124
Abstract:
Objective To develop an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determining lutein and natural vitamin K (VK) homologues, including phylloquinone (VK1), menaquinone-4 (MK-4), menaquinone-7 (MK-7), and menaquinone-9 (MK-9), in poultry eggs by optimizing ultrasound assisted enzymatic hydrolysis.Methods The target compound is extracted from poultry egg samples by ultrasound assisted enzymatic hydrolysis and then separated on C18 (100 mm×2.1 mm, 3.0 μm) column with 0.1% formic acid aqueous solution-0.1% formic acid methanol for gradient elution. Meanwhile, the samples are quantified by external standard with APCI source for detection and analysis.Results Under the ultrasound assisted enzymatic hydrolysis conditions of enzyme dosage of 1 500 U and hydrolysis time of 1 hour, the linear relationships of lutein and natural VK homologues are good in the range from 1.0 ng/mL to 5 000 ng/mL (R2>0.996). The detection limit is 0.8~1.5 μg/100 g, and the quantification limit is 2.0~5.0 μg/100 g. The average recovery of lutein and natural VK homologues is 80.1%~94.9% when the spiked concentration is 10, 20, and 100 μg/100 g with the RSD of 1.3%~5.5%.Conclusion This method has high detection efficiency, sensitivity, and selectivity and can be used as a detection method for lutein and natural VK homologues in poultry eggs.
Objective To develop an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determining lutein and natural vitamin K (VK) homologues, including phylloquinone (VK1), menaquinone-4 (MK-4), menaquinone-7 (MK-7), and menaquinone-9 (MK-9), in poultry eggs by optimizing ultrasound assisted enzymatic hydrolysis.Methods The target compound is extracted from poultry egg samples by ultrasound assisted enzymatic hydrolysis and then separated on C18 (100 mm×2.1 mm, 3.0 μm) column with 0.1% formic acid aqueous solution-0.1% formic acid methanol for gradient elution. Meanwhile, the samples are quantified by external standard with APCI source for detection and analysis.Results Under the ultrasound assisted enzymatic hydrolysis conditions of enzyme dosage of 1 500 U and hydrolysis time of 1 hour, the linear relationships of lutein and natural VK homologues are good in the range from 1.0 ng/mL to 5 000 ng/mL (R2>0.996). The detection limit is 0.8~1.5 μg/100 g, and the quantification limit is 2.0~5.0 μg/100 g. The average recovery of lutein and natural VK homologues is 80.1%~94.9% when the spiked concentration is 10, 20, and 100 μg/100 g with the RSD of 1.3%~5.5%.Conclusion This method has high detection efficiency, sensitivity, and selectivity and can be used as a detection method for lutein and natural VK homologues in poultry eggs.
2025, 41(11):20-27.
DOI: 10.13652/j.spjx.1003.5788.2025.80026
Abstract:
Objective To investigate the factors affecting the extraction rate, characteristic aroma components, and stability of Phyllanthus emblica L. extracts from different producing areas.Methods Five types of P. emblica from four producing areas, including Guangdong, Yunnan, Jiangxi, and Sichuan, were used as raw materials. Orthogonal experiments were conducted to study the effects of various factors on the extraction rate. Gas chromatography-mass spectrometry (GC-MS) analysis and similarity calculations were used to compare the characteristic aroma components of P. emblica extracts from different producing areas. The stability of the extracts was evaluated based on appearance, relative density, and sugar content.Results Among the producing areas, dried P. emblica from Yunnan had the highest extraction rate, with solvent and material-to-liquid ratio being the main factors influencing extraction. GC-MS analysis showed that characteristic aroma components of extracts from Guangdong included furfural, furfuralcohol, pyranone, 5-hydroxymethylfurfural, and ethyl palmitate, whereas extracts from Yunnan were characterized by 3-methyl-2-furanic acid and dibutyl phthalate. The similarity between these two extracts was only 0.943 6.Conclusion All five P. emblica extracts exhibited a prominent fruity-sweet aroma. However, there were significant differences in characteristic aroma components among different producing areas and varieties. The extracts also demonstrated good preservation and usage stability over a certain period.
Objective To investigate the factors affecting the extraction rate, characteristic aroma components, and stability of Phyllanthus emblica L. extracts from different producing areas.Methods Five types of P. emblica from four producing areas, including Guangdong, Yunnan, Jiangxi, and Sichuan, were used as raw materials. Orthogonal experiments were conducted to study the effects of various factors on the extraction rate. Gas chromatography-mass spectrometry (GC-MS) analysis and similarity calculations were used to compare the characteristic aroma components of P. emblica extracts from different producing areas. The stability of the extracts was evaluated based on appearance, relative density, and sugar content.Results Among the producing areas, dried P. emblica from Yunnan had the highest extraction rate, with solvent and material-to-liquid ratio being the main factors influencing extraction. GC-MS analysis showed that characteristic aroma components of extracts from Guangdong included furfural, furfuralcohol, pyranone, 5-hydroxymethylfurfural, and ethyl palmitate, whereas extracts from Yunnan were characterized by 3-methyl-2-furanic acid and dibutyl phthalate. The similarity between these two extracts was only 0.943 6.Conclusion All five P. emblica extracts exhibited a prominent fruity-sweet aroma. However, there were significant differences in characteristic aroma components among different producing areas and varieties. The extracts also demonstrated good preservation and usage stability over a certain period.
2025, 41(11):28-34.
DOI: 10.13652/j.spjx.1003.5788.2025.80052
Abstract:
Objective To realize the geographical discrimination of early spring green tea of Huangjincha from major production areas in Hunan based on mineral element fingerprinting.Methods A total of 138 early spring green tea samples of Huangjincha from different regions in Hunan were quantitatively analyzed for 48 mineral elements using inductively coupled plasma mass spectrometry (ICP-MS). Classification models for different production areas were developed by integrating principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and Fisher's linear discriminant analysis.Results The PCA score plots and OPLS-DA models effectively distinguished Huangjincha samples from various production areas in Hunan. A geographical discrimination model was constructed using Fisher's linear discriminant analysis based on 10 key elements (Ba, Al, B, Sm, K, Ga, Te, Rb, Co, Eu), achieving an overall prediction accuracy of over 90%.Conclusion Mineral element fingerprinting can be effectively applied to the origin traceability of Huangjincha from major production areas in Hunan.
Objective To realize the geographical discrimination of early spring green tea of Huangjincha from major production areas in Hunan based on mineral element fingerprinting.Methods A total of 138 early spring green tea samples of Huangjincha from different regions in Hunan were quantitatively analyzed for 48 mineral elements using inductively coupled plasma mass spectrometry (ICP-MS). Classification models for different production areas were developed by integrating principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and Fisher's linear discriminant analysis.Results The PCA score plots and OPLS-DA models effectively distinguished Huangjincha samples from various production areas in Hunan. A geographical discrimination model was constructed using Fisher's linear discriminant analysis based on 10 key elements (Ba, Al, B, Sm, K, Ga, Te, Rb, Co, Eu), achieving an overall prediction accuracy of over 90%.Conclusion Mineral element fingerprinting can be effectively applied to the origin traceability of Huangjincha from major production areas in Hunan.
2025, 41(12):2-10.
DOI: 10.13652/j.spjx.1003.5788.2025.80119
Abstract:
Objective To investigate the trends in enzyme activity and structural changes during black tea processing, and to analyze the functional expression of polyphenol oxidase (PPO), peroxidase (POD), β-glucosidase (β-GC), and protease, aiming to optimize the processing technology of Gougunao black tea.Methods Using one bud and one leaf of the Gougunao population as raw materials, Gougunao black tea was prepared by traditional processing technology. The relative browning degree and tea polyphenol content during processing were measured. The activity and structural changes of PPO, POD, β-GC, and protease were analyzed, and the enzyme functional expression mechanisms were explored.Results The relative browning degree increased during black tea processing, reaching a maximum of 503.21% during the first drying stage. Tea polyphenol content decreased to 15.4%, with the largest decline occurring after fermentation. Activities of PPO, POD, and β-GC showed a decreasing trend, whereas protease activity exhibited an increase-decrease-increase pattern. UV-visible and Fourier transform infrared (FTIR) spectra revealed significant conformational changes in PPO during fresh leaves, withering, and rolling. POD's enzyme structure changed during fermentation, first drying, and final drying, with a marked decrease in activity during fermentation. Beta-GC exhibited distinct absorption peaks during withering, rolling, and drying, with a continuous decrease in activity. Protease showed characteristic absorption peaks throughout processing, with activity decreasing during withering and increasing during first drying. X-ray diffraction (XRD) spectra indicated that PPO, β-GC, and protease were amorphous polymers, while POD's three-dimensional conformation changed.Conclusion Significant changes occurred in the enzyme activities and structures of PPO, POD, β-GC, and protease during Gougunao black tea processing.
Objective To investigate the trends in enzyme activity and structural changes during black tea processing, and to analyze the functional expression of polyphenol oxidase (PPO), peroxidase (POD), β-glucosidase (β-GC), and protease, aiming to optimize the processing technology of Gougunao black tea.Methods Using one bud and one leaf of the Gougunao population as raw materials, Gougunao black tea was prepared by traditional processing technology. The relative browning degree and tea polyphenol content during processing were measured. The activity and structural changes of PPO, POD, β-GC, and protease were analyzed, and the enzyme functional expression mechanisms were explored.Results The relative browning degree increased during black tea processing, reaching a maximum of 503.21% during the first drying stage. Tea polyphenol content decreased to 15.4%, with the largest decline occurring after fermentation. Activities of PPO, POD, and β-GC showed a decreasing trend, whereas protease activity exhibited an increase-decrease-increase pattern. UV-visible and Fourier transform infrared (FTIR) spectra revealed significant conformational changes in PPO during fresh leaves, withering, and rolling. POD's enzyme structure changed during fermentation, first drying, and final drying, with a marked decrease in activity during fermentation. Beta-GC exhibited distinct absorption peaks during withering, rolling, and drying, with a continuous decrease in activity. Protease showed characteristic absorption peaks throughout processing, with activity decreasing during withering and increasing during first drying. X-ray diffraction (XRD) spectra indicated that PPO, β-GC, and protease were amorphous polymers, while POD's three-dimensional conformation changed.Conclusion Significant changes occurred in the enzyme activities and structures of PPO, POD, β-GC, and protease during Gougunao black tea processing.
2025, 41(12):11-18.
DOI: 10.13652/j.spjx.1003.5788.2024.80152
Abstract:
Objective To obtain the best strain combination for fermenting traditional kombucha by screening the bacterial strains.Methods The strains isolated from traditional kombucha are evaluated in terms of the production of acids and alcohols. Three strains of acetic acid bacteria and four strains of yeast screened out are combined to form 12 fermentation groups for the production of kombucha, which are analyzed by gas chromatography-mass spectrometry (GC-MS) combined with the physicochemical and microbiological assays and sensory evaluation of the products.Results The acidity of the fermentation groups M6 (Komagataeibacter saccharivorans and Saccharomyces cerevisiae) and M12 (Acetobacter and S. cerevisiae) at the fermentation endpoint is 0.537 g/100 g and 0.495 g/100 g, respectively, higher than that of most fermentation groups. The microbial counts of the two groups reach the average level of all the fermentation groups. The two groups show significant differences in content of tea polyphenols, caffeine, and ethanol compared with some fermentation groups (P<0.05). GC-MS results reveal that the characteristic flavor compound in M6 and M12 groups is ethyl acetate, with the mass fractions of 20.12% and 19.08%, respectively. The results above combined with the sensory evaluation scores suggest that the M6 and M12 groups are superior to the other fermentation groups in terms of flavor, color, and sensory quality.Conclusion The M6 and M12 fermentation groups can be used as effective strain combinations for the production of traditional kombucha, improving the physicochemical indexes, flavor compounds, and sensory quality of traditional kombucha.
Objective To obtain the best strain combination for fermenting traditional kombucha by screening the bacterial strains.Methods The strains isolated from traditional kombucha are evaluated in terms of the production of acids and alcohols. Three strains of acetic acid bacteria and four strains of yeast screened out are combined to form 12 fermentation groups for the production of kombucha, which are analyzed by gas chromatography-mass spectrometry (GC-MS) combined with the physicochemical and microbiological assays and sensory evaluation of the products.Results The acidity of the fermentation groups M6 (Komagataeibacter saccharivorans and Saccharomyces cerevisiae) and M12 (Acetobacter and S. cerevisiae) at the fermentation endpoint is 0.537 g/100 g and 0.495 g/100 g, respectively, higher than that of most fermentation groups. The microbial counts of the two groups reach the average level of all the fermentation groups. The two groups show significant differences in content of tea polyphenols, caffeine, and ethanol compared with some fermentation groups (P<0.05). GC-MS results reveal that the characteristic flavor compound in M6 and M12 groups is ethyl acetate, with the mass fractions of 20.12% and 19.08%, respectively. The results above combined with the sensory evaluation scores suggest that the M6 and M12 groups are superior to the other fermentation groups in terms of flavor, color, and sensory quality.Conclusion The M6 and M12 fermentation groups can be used as effective strain combinations for the production of traditional kombucha, improving the physicochemical indexes, flavor compounds, and sensory quality of traditional kombucha.
2025, 41(11):41-44.
DOI: 10.13652/j.spjx.1003.5788.2025.60144
Abstract:
From the perspective of China's criminal law practices and their effectiveness in addressing food safety issues, the main deficiencies in the current criminal regulation of food safety in China are manifested in three areas: the unreasonable classification of offenses within chapters, the absence of provisions for negligent crimes, and the lack of a mandatory qualification penalty, along with the rigidity of the prohibition order. In response, this article proposes improvement to the current criminal regulation of food safety by reasonably determining the classification of offenses within chapters, scientifically adding specific provisions for negligent crimes, and optimizing the design of the qualification penalty and prohibition order within the criminal punishment system.
From the perspective of China's criminal law practices and their effectiveness in addressing food safety issues, the main deficiencies in the current criminal regulation of food safety in China are manifested in three areas: the unreasonable classification of offenses within chapters, the absence of provisions for negligent crimes, and the lack of a mandatory qualification penalty, along with the rigidity of the prohibition order. In response, this article proposes improvement to the current criminal regulation of food safety by reasonably determining the classification of offenses within chapters, scientifically adding specific provisions for negligent crimes, and optimizing the design of the qualification penalty and prohibition order within the criminal punishment system.
2025, 41(10):11-19.
DOI: 10.13652/j.spjx.1003.5788.2024.81122
Abstract:
Objective To explore the effects of cooking methods on the differences in characteristic volatile compounds of Huchen potato, a nationally recognized geographical indication agricultural product.Methods Taking Huchen potato as the research subject, gas chromatography-ion mobility spectrometry (GC-IMS) combined with fingerprint analysis technology was used to explore the impact of four cooking methods on its volatile flavor substances.Results The volatile flavor substances of Huchen potato are mainly alcohols, aldehydes, and ketones. The four cooking methods caused significant differences in their characteristic volatile flavor components. Alcohol content ranked as steaming > pan-frying > roasting > deep-frying; aldehyde content ranked as pan-frying > deep-frying > roasting > steaming; ketone content ranked as roasting > steaming > deep-frying > pan-frying. Fingerprint analysis showed that compared with the other three cooking methods, pan-frying significantly enhanced the fruity aroma of Huchen potato.Conclusion GC-IMS combined with fingerprint analysis technology can effectively distinguish the differences in volatile flavor components of potatoes prepared by different cooking methods.
Objective To explore the effects of cooking methods on the differences in characteristic volatile compounds of Huchen potato, a nationally recognized geographical indication agricultural product.Methods Taking Huchen potato as the research subject, gas chromatography-ion mobility spectrometry (GC-IMS) combined with fingerprint analysis technology was used to explore the impact of four cooking methods on its volatile flavor substances.Results The volatile flavor substances of Huchen potato are mainly alcohols, aldehydes, and ketones. The four cooking methods caused significant differences in their characteristic volatile flavor components. Alcohol content ranked as steaming > pan-frying > roasting > deep-frying; aldehyde content ranked as pan-frying > deep-frying > roasting > steaming; ketone content ranked as roasting > steaming > deep-frying > pan-frying. Fingerprint analysis showed that compared with the other three cooking methods, pan-frying significantly enhanced the fruity aroma of Huchen potato.Conclusion GC-IMS combined with fingerprint analysis technology can effectively distinguish the differences in volatile flavor components of potatoes prepared by different cooking methods.
2022(5):234-240.
DOI: 10.13652/j.spjx.1003.5788.2022.60025
Abstract:
This review introduced the classification, structure and physical and chemical properties of dietary fiber, and summarized the relevant research literature on the modification methods and physicochemical properties of dietary fiber at home and abroad in recent years. The development direction of the physicochemical properties of dietary fiber and its modification methods were also prospected, in order to provide a theoretical reference for its efficient and comprehensive utilization.
This review introduced the classification, structure and physical and chemical properties of dietary fiber, and summarized the relevant research literature on the modification methods and physicochemical properties of dietary fiber at home and abroad in recent years. The development direction of the physicochemical properties of dietary fiber and its modification methods were also prospected, in order to provide a theoretical reference for its efficient and comprehensive utilization.
2025, 41(11):50-57.
DOI: 10.13652/j.spjx.1003.5788.2025.80115
Abstract:
Objective To investigate the enhancement effect of self-excited thermoacoustic oscillation on the drying process of solid foods.Methods A pulsating hot air drying device based on a Rijke tube resonator structure is designed. White radish slices are selected as the target material to study the effects of hot air temperature (100~140 ℃), airflow velocity (1~7 m/s), and layer thickness (4~12 mm) on drying kinetics and product quality.Results The device can stably generate a self-excited pulsating airflow with a temperature of 140 ℃, frequency of 147 Hz, and sound pressure level of 94 dB, which significantly improves drying efficiency compared to traditional non-pulsed drying methods. Under a 100 ℃ working condition, the drying time is reduced from 165 min to 135 min (an 18% decrease), and the enhancement effect increased with temperature (at 140 ℃, the drying rate tripled). With optimized parameters (100 ℃, 1 m/s airflow, 8 mm material thickness), the shrinkage rate (67%), rehydration ratio (4.66), and whiteness (70.18) of the white radish slices are improved compared to conventional drying.Conclusion Thermoacoustic oscillation enhances heat and mass transfer efficiency by periodically disturbing the thermal boundary layer, while also reducing structural damage to the material caused by high temperatures.
Objective To investigate the enhancement effect of self-excited thermoacoustic oscillation on the drying process of solid foods.Methods A pulsating hot air drying device based on a Rijke tube resonator structure is designed. White radish slices are selected as the target material to study the effects of hot air temperature (100~140 ℃), airflow velocity (1~7 m/s), and layer thickness (4~12 mm) on drying kinetics and product quality.Results The device can stably generate a self-excited pulsating airflow with a temperature of 140 ℃, frequency of 147 Hz, and sound pressure level of 94 dB, which significantly improves drying efficiency compared to traditional non-pulsed drying methods. Under a 100 ℃ working condition, the drying time is reduced from 165 min to 135 min (an 18% decrease), and the enhancement effect increased with temperature (at 140 ℃, the drying rate tripled). With optimized parameters (100 ℃, 1 m/s airflow, 8 mm material thickness), the shrinkage rate (67%), rehydration ratio (4.66), and whiteness (70.18) of the white radish slices are improved compared to conventional drying.Conclusion Thermoacoustic oscillation enhances heat and mass transfer efficiency by periodically disturbing the thermal boundary layer, while also reducing structural damage to the material caused by high temperatures.
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