Probiotics crosstalk immunity to improve host glycolipid metabolism,which is a new strategy for obesity.This study aimed to explore the functions of Lacticaseibacillus paracasei K56(K56),in regulating the lipid metabo...Probiotics crosstalk immunity to improve host glycolipid metabolism,which is a new strategy for obesity.This study aimed to explore the functions of Lacticaseibacillus paracasei K56(K56),in regulating the lipid metabolism of adipocytes and its immune regulation mechanisms.We co-cultured RAW264.7 macrophages with K56,and the K56-stimulated RAW264.7-conditioned medium(K56-CM)was collected and treated with 3T3-L1 pre-adipocytes.The expression of lipid metabolism-related markers of adipocytes,and the content of cytokines in CMs were detected.The results demonstrated that K56-CM promoted the expression of peroxisome proliferator-activated receptor-γ(PPAR-γ),CCAAT/enhancer binding proteinα(C/EBPα),and other adipogenesis-related markers,which resulted in the upregulation of lipolysis markers,such as hormone-sensitive lipase(HSL),adipose triglyceride lipase(ATGL).The activation of lipolysis enhanced the expression of fatty acidβ-oxidation-related and mitochondrial biogenesis-related markers and reduced lipid accumulation in adipocytes.The glycolipid metabolism pattern of K56 may be due to its immunomodulatory characteristics,which stimulated macrophages to secrete fewer TNF-α,thereby promoting the expression of lipolysis-related markers,and TNF-αsynergized with lipase to promote lipolysis.It has not been reported that L.paracasei modulated lipid metabolism via the lipolysis pathway,which suggested that K56 may regulate glycolipid metabolism of the host by maintaining immune homeostasis.展开更多
The rapid identification of lactic acid bacteria,which are essential microorganisms in the food industry,is of great significance for industrial applications.The identification of lactic acid bacteria traditionally re...The rapid identification of lactic acid bacteria,which are essential microorganisms in the food industry,is of great significance for industrial applications.The identification of lactic acid bacteria traditionally relies on the isolation and identification of pure colonies.While this method is well-established and widely used,it is not without limitations.The subjective judgment inherent in the isolation and purification process introduces potential for error,and the incomplete nature of the isolation process can result in the loss of valuable information.The advent of next generation sequencing has provided a novel approach to the rapid identification of lactic acid bacteria.This technology offers several advantages,including rapidity,accuracy,high throughput,and low cost.Next generation sequencing represents a significant advancement in the field of DNA sequencing.Its ability to rapidly and accurately identify lactic acid bacteria strains in samples with insufficient information or in the presence of multiple lactic acid bacteria sets it apart as a valuable tool.The application of this technology not only circumvents the potential errors inherent in the traditional method but also provides a robust foundation for the expeditious identification of lactic acid bacteria strains and the authentication of bacterial powder in industrial applications.This paper commences with an overview of traditional and molecular biology methods for the identification of lactic acid bacteria.While each method has its own advantages,they are not without limitations in practical application.Subsequently,the paper provides an introduction of the principle,process,advantages,and disadvantages of next generation sequencing,and also details its application in strain identification and rapid identification of lactic acid bacteria.The objective of this study is to provide a comprehensive and reliable basis for the rapid identification of industrial lactic acid bacteria strains and the authenticity identification of bacterial powder.展开更多
Microplastics are plastic particles or fibers with a diameter of less than 5 mm,and they widely exist in the environment and pose potential risks to the ecosystem and human health.Microplastics detection can provide b...Microplastics are plastic particles or fibers with a diameter of less than 5 mm,and they widely exist in the environment and pose potential risks to the ecosystem and human health.Microplastics detection can provide basic data for formulating effective environmental protection strategies.In this paper,the physical,chemical and biological detection methods of microplastics are reviewed,and the advantages and disadvantages of different methods are analyzed.The problems and challenges encountered in microplastics detection are analyzed,and the future research is discussed.展开更多
[Objectives]To verify the specificity,sensitivity,precision and negative-positive deviation of the foodproof gluten component de-tection kit for the detection of gluten allergens in milk powder matrix,and to establish...[Objectives]To verify the specificity,sensitivity,precision and negative-positive deviation of the foodproof gluten component de-tection kit for the detection of gluten allergens in milk powder matrix,and to establish a real-time fluorescent PCR legal method for the detec-tion of gluten allergens in milk powder.[Methods]The specificity,sensitivity,precision and negative-positive deviation of the detection method of foodproof gluten component detection kit(PCR-probe method)were verified by artificially adding different concentrations of wheat bran and extracting sample DNA by kit method,and applied to sample detection.[Results] The specific detection results of two kinds of milk powder with wheat bran and buckwheat added showed that the foodproof gluten component detection kit(PCR-probe method)had good speci-ficity for wheat gluten.The results of artificially added wheat bran positive samples showed that the false positive rate and false negative rate of the kit in the milk powder matrix were O,and the sensitivity and precision were high.[Conclusions]The kit is simple to operate and has high accuracy,which is suitable for the detection of gluten allergen components in milk powder.展开更多
Microplastics pollution has become one of the focuses of global environmental science research.Microplastics include micro plastic particles and nano-plastic particles,which come from the decomposition of plastic prod...Microplastics pollution has become one of the focuses of global environmental science research.Microplastics include micro plastic particles and nano-plastic particles,which come from the decomposition of plastic products,the release of microfibers and the industrial process of plastic particles.The distribution of microplastics in water,soil and atmosphere is summarized,and the widespread existence of microplastics in different environmental media is emphasized.This paper also summarizes the potential impact of microplastics on ecosystems and organisms,and pays attention to the transmission and accumulation of microplastics in the food chain,as well as its potential threat to human health.Finally,the paper discusses the methods and technologies of microplastics treatment and monitoring at present,and puts forward the direction of further research on microplastics pollution in order to formulate more effective management and mitigation strategies.展开更多
As a new type of environmental pollutants,microplastics have gradually attracted people's attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and ...As a new type of environmental pollutants,microplastics have gradually attracted people's attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and finally become microplastics.Microplastics can adsorb pollutants in the environment,and their components have certain toxicity,which can cause different degrees of harm to organisms.Due to the structural characteristics of microplastic particles,such as small particle size,large specific surface area,and their distribution in different environmental media,it is very difficult to accurately detect microplastics.Reliable collection and detection methods are the key to the study of environmental behavior of microplastics.In this study,the collection and detection methods of microplastics in the environment were reviewed,and the development direction of microplastics detection technology in the future was prospected.This study has a certain reference value for the related research and the prevention and treatment of micro-plastic pollution.展开更多
In this paper,by combining sampling methods for food statistics with years of sample sampling experience,various sampling points and corresponding sampling methods are summarized.It hopes to discover food safety risks...In this paper,by combining sampling methods for food statistics with years of sample sampling experience,various sampling points and corresponding sampling methods are summarized.It hopes to discover food safety risks and improve the level of food safety.展开更多
Pasteurized milk contains complex microbial communities affected by sterilization and storage conditions.This complex microflora may be the possible reason that pasteurized dairy products are highly prone to spoilage....Pasteurized milk contains complex microbial communities affected by sterilization and storage conditions.This complex microflora may be the possible reason that pasteurized dairy products are highly prone to spoilage.In this study,packaged pasteurized milk products collected from dairy processing factories in China were stored at 0,4,10,15,and 25℃ for 0−15 days and subjected to microbial identification using high-throughput sequencing.Accordingly,6 phyla and 44 genera were identified as the dominant microbiota.Moreover,the changes in nutritional composition of the pasteurized milk,including in 16 free amino acids,7 taste values,and 8 chemical constituents,were analyzed using principal component and multi-factor analyses.The Pearson correlation analysis identified Pseudomonas,Aeromonas,Paenibacillus,and Serratia genera as the core functional microbiota that significantly affects the nutritional composition of pasteurized milk.Hence,the results provide a comprehensive understanding of the safety and shelf-life of stored pasteurized milk.展开更多
[Objectives]The paper was to establish an evaluation method for the uncertainty of stevioside(including stevioside,rebaudioside A,rebaudioside B,rebaudioside C,rebaudioside F,Dulcoside A,rubusoside and steviolbioside)...[Objectives]The paper was to establish an evaluation method for the uncertainty of stevioside(including stevioside,rebaudioside A,rebaudioside B,rebaudioside C,rebaudioside F,Dulcoside A,rubusoside and steviolbioside)content determination in fermented milk based on HPLC.[Methods]The mathematical model of stevioside content and the propagation rate of uncertainty were established,and the sources of uncertainty were analyzed.[Results]The uncertainty mainly came from four main aspects,including standard uncertainty u(C)introduced by solution concentration C,standard uncertainty u(V)introduced by sample volume V,standard uncertainty u(m)introduced by sample mass m weighing and standard uncertainty u(f_(rep))introduced by measurement repeatability of stevioside content after sample dissolution and constant volume.The uncertainty estimation table and fishbone chart of stevioside content X determination were established.The relative synthetic standard uncertainty of stevioside content was obtained,and the standard uncertainty was extended to form the measurement result of stevioside content and its uncertainty report.[Conclusions]The evaluation results can be directly applied to the daily practical detection work.展开更多
[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA ...[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA was extracted for amplification of 16S rDNA and gyrB gene.The 16S rDNA and gyrB gene sequences were obtained after sequencing.Sequences were aligned and analyzed via EzBioCloud and NCBI database,and phylogenetic trees were constructed to determine the species relationship of strains.Meantime,they were compared with known strains.[Results]This method could identify 5 standard strains accurately to the species level.The 16S rDNA and gyrB gene sequences were aligned and analyzed in EzBioCloud database and NCBI database.The strain with the max score was consistent with the known strain.And the query cover and ident were both above 99%.[Conclusions]The established molecular biological method for identification of bacterial strains by 16S rDNA and gyrB gene has good accuracy,which effectively solves the problem that the laboratory identification of bacteria relies on traditional methods and the accuracy can not be guaranteed,and further improves the identification ability of laboratory bacterial strains.展开更多
As the global economy enters a new stage,Chinese dairy enterprises are gradually moving towards the road of internationalization.In this paper,the internationally common quality management system,food safety system an...As the global economy enters a new stage,Chinese dairy enterprises are gradually moving towards the road of internationalization.In this paper,the internationally common quality management system,food safety system and quality traceability system were analyzed and studied to promote the comprehensive transformation and upgrading of dairy industry and broaden the development road with the help of systematic construction.展开更多
With the development of economy,people's living standards are constantly improving,and the requirements for food safety are getting higher and higher.The Food Safety Law stipulates that enterprises should implemen...With the development of economy,people's living standards are constantly improving,and the requirements for food safety are getting higher and higher.The Food Safety Law stipulates that enterprises should implement the main responsibility of food safety,and the investigation and improvement of food safety hazards plays an important role in improving the food safety management level of enterprises and reducing food safety risks.This paper combines the innovative thinking mode of six thinking hats with food safety,discusses the application mode of six thinking hats in food safety investigation and improvement,and hopes to improve food safety level through this way.展开更多
[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the...[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.展开更多
[Objectives]To determine the aerobic plate count(APC)in the milk samples,evaluate the uncertainty of the test results,and to provide a scientific basis for the quality control of the testing process.[Methods]In compli...[Objectives]To determine the aerobic plate count(APC)in the milk samples,evaluate the uncertainty of the test results,and to provide a scientific basis for the quality control of the testing process.[Methods]In compliance with the national food safety standard Food Microbiological Examination:Aerobic Plate Count(GB 4789.2-2016),the aerobic plate count in the milk samples was detected.The source of the uncertainty of the test result was analyzed and a mathematical model was established in accordance with Evaluation and Expression of Uncertainty in Measurement(JJF 1059.1-2012).Then,the introduced uncertainty components were evaluated to determine the uncertainty of the final combined aerobic plate count.[Results]The expanded uncertainty of the test result of the aerobic plate count in the milk samples was 0.0434,and the logarithmic value interval of the results was(3.924,4.010),and the antilogarithm was taken to get the aerobic plate count in the sample to be 8395-10233 CFU/mL.[Conclusions]This method can effectively evaluate the uncertainty of the aerobic plate count,and ensure the accurate and scientific laboratory test data.展开更多
BACKGROUND Gastrointestinal(GI)discomforts are common in the elderly population;however,whether such discomforts are associated with dietary intake has not been studied.AIM To evaluate GI discomforts in Chinese urban ...BACKGROUND Gastrointestinal(GI)discomforts are common in the elderly population;however,whether such discomforts are associated with dietary intake has not been studied.AIM To evaluate GI discomforts in Chinese urban elders and the associated factors.METHODS The gastrointestinal symptom rating scale(GSRS)was used to identify GI discomforts in 688 elders from eight cities of China.The semi-quantitative food frequency questionnaire and one time of 24 h dietary recall were used to access the food intake,identify dietary pattern,and calculate the nutrients intake.RESULTS About 83%of studied elders experienced at least one of GI discomforts in the past 6 mo;dyspepsia was the most commonly reported(66.7%),followed by reflux(44.8%),abdominal pain(35.9%),constipation(35.8%),and diarrhea(34.7%).Female gender,lower education level,and lower family income were associated with a higher GSRS score.Participants who were diagnosed with a GI-related disease had a higher score of constipation,but a lower score of reflux.Chronic diseases were positively associated with certain GI discomforts.Three dietary patterns were identified by the method of principal component analysis,which were characterized as high intake of salt and tea;more frequent intake of tubers,fruits,aquatic products,and soybeans;and high intake of cereal,vegetables,and meat,respectively.However,no associations between dietary patterns and GSRS score were found.The elders with a higher GSRS score had significantly lower intake of bean products.The elders whose GSRS score was≥21 and 18-20 decreased their bean production intake by 7.2(0.3,14.3)g/d and 14.3(1.2,27.3)g/d,respectively,compared with those who had a GSRS score≤17.There were no differences in other food categories,calories,or nutrients intake among elders with different GSRS scores.CONCLUSION GI discomforts are common in Chinese urban elders.GI discomforts might be associated with the choice of food.展开更多
[Objectives]To accurately determine the naringin content in Rhizoma Drynariae.[Methods]The high performance liquid chromatography(HPLC)method was applied in the determination of the naringin content in Rhizoma Drynari...[Objectives]To accurately determine the naringin content in Rhizoma Drynariae.[Methods]The high performance liquid chromatography(HPLC)method was applied in the determination of the naringin content in Rhizoma Drynariae.The sample was sonicated at room temperature.The mobile phase was 0.1%phosphoric acid-acetonitrile(75∶25),detected by diode array detector at the wavelength of 284 nm,and quantified by external standard method.[Results]The linearity of naringin was good in the concentration range of 5-500μg/mL with a correlation coefficient of 0.9999.[Conclusions]This method has good linearity,easy operation,correctness and reproducibility as required,and is expected to provide a method for the determination of naringin content in Rhizoma Drynariae.展开更多
[Objectives]To make simultaneous determination of vitamin K_(1)(VK_(1))and vitamin K_(2)(VK_(2),mainly MK-4,MK-7 and MK-9)in milk and dairy products.[Methods]A high performance liquid chromatographic method was develo...[Objectives]To make simultaneous determination of vitamin K_(1)(VK_(1))and vitamin K_(2)(VK_(2),mainly MK-4,MK-7 and MK-9)in milk and dairy products.[Methods]A high performance liquid chromatographic method was developed for the simultaneous determination of vitamin K_(1)(VK_(1))and vitamin K_(2)(VK_(2),mainly MK-4,MK-7 and MK-9)in milk and dairy products.After enzymatic digestion,the samples were extracted with hexane for VK_(1),MK-4,MK-7 and MK-9,subjected to gradient elution at excitation wavelength 243 nm and emission wavelength 430 nm,detected by high performance liquid chromatography with fluorescence detector and quantified by external standard method.[Results]The linearity of VK_(1),MK-4,MK-7 and MK-9 was good in the concentration range of 2.5-1000 ng/mL with the correlation coefficients greater than 0.999;The relative standard deviations(RSD)of VK_(1),MK-4,MK-7 and MK-9 in milk powder,liquid milk and yogurt were 1.32%-5.05%,1.10%-2.48% and 2.20%-3.47%,respectively;the recovery rates of VK_(1),MK-4,MK-7 and MK-9 at different levels in milk powder,liquid milk and yogurt were 81.1%-108%,81.8%-103%and 82.1%-99.2%,respectively.[Conclusions]The method is rapid,accurate,reproducible and capable of simultaneous determination of VK_(1),MK-4,MK-7 and MK-9.展开更多
In this paper,the six Aigma DMAIC method was used to systematically analyze and study the process affecting the good rate of blank value of cytological method for dairy products.Through data collection,analysis and ve...In this paper,the six Aigma DMAIC method was used to systematically analyze and study the process affecting the good rate of blank value of cytological method for dairy products.Through data collection,analysis and verification in each link,the room for improvement in the experimental process was identified.C&E matrix and FMEA were used to analyze the factors affecting the good rate of blank value.Through the DOE experiment design method and risk analysis,the main influencing factors were optimized and improved.The optimized experimental conditions were:silica gel activation temperature(500±50)℃,activation time(23±1)h,cells adherent rate(95±1)%,and single-use of 1.5 mL conical flask.Under the above conditions,the good rate of blank value of cytological method was improved from 52.8%to 100%.The improvement of these conditions is of great significance to ensure the accuracy of results,save the testing cost and improve the testing efficiency.展开更多
[Objectives]To explore the inhibitory effect of lactic acid bacteria(LAB)on the growth of Salmonella.[Methods]The inhibitory effect of lactic acid bacteria on Salmonella was investigated by Oxford cup agar diffusion t...[Objectives]To explore the inhibitory effect of lactic acid bacteria(LAB)on the growth of Salmonella.[Methods]The inhibitory effect of lactic acid bacteria on Salmonella was investigated by Oxford cup agar diffusion test from the aspects of lactic acid bacteria body,metabolites,pH,thermal stability and acid resistance.[Results]The growth of Salmonella was disturbed by the inhibition of lactic acid bacteria.The mechanism of inhibitory effect may be:simple low pH and lactic acid bacteria have no inhibitory effect on Salmonella;however,there are active substances in the metabolites of lactic acid bacteria,which have high thermal stability and a wide range of acid resistance,and are effective substances for inhibiting the growth of Salmonella.[Conclusions]This study is helpful for screening more natural preservative substances,reducing the contamination rate of Salmonella to food,and is expected to provide a theoretical basis for the preservation and preservation of food.展开更多
[Objectives]To determine the content of organic pollutants by CALUX bioassay.[Methods]According to JJF 1059.1-2012 Technical Specification for Evaluation and Expression of Uncertainty in Measurement,the determination ...[Objectives]To determine the content of organic pollutants by CALUX bioassay.[Methods]According to JJF 1059.1-2012 Technical Specification for Evaluation and Expression of Uncertainty in Measurement,the determination results of organic pollutants were analyzed,various sources of uncertainty that may be introduced in the detection process were analyzed,and the mathematical model of uncertainty was established.Type A and B evaluation methods were used to calculate the components of uncertainty and extended uncertainty.[Results]In the range of 95%confidence interval,the determination result of organic pollutants was 6.59 pg/g fat,and the extended uncertainty was 0.0764 pg/g fat,so the determination results of organic pollutants could be expressed as(6.59±0.0764)pg/g fat(k=2).[Conclusions]This study can provide a basis for more accurate determination of organic pollutants.展开更多
基金supported by the Yili Industrial Group Co.,Ltd.,and National Natural Science Foundation of China(81973042).T。
文摘Probiotics crosstalk immunity to improve host glycolipid metabolism,which is a new strategy for obesity.This study aimed to explore the functions of Lacticaseibacillus paracasei K56(K56),in regulating the lipid metabolism of adipocytes and its immune regulation mechanisms.We co-cultured RAW264.7 macrophages with K56,and the K56-stimulated RAW264.7-conditioned medium(K56-CM)was collected and treated with 3T3-L1 pre-adipocytes.The expression of lipid metabolism-related markers of adipocytes,and the content of cytokines in CMs were detected.The results demonstrated that K56-CM promoted the expression of peroxisome proliferator-activated receptor-γ(PPAR-γ),CCAAT/enhancer binding proteinα(C/EBPα),and other adipogenesis-related markers,which resulted in the upregulation of lipolysis markers,such as hormone-sensitive lipase(HSL),adipose triglyceride lipase(ATGL).The activation of lipolysis enhanced the expression of fatty acidβ-oxidation-related and mitochondrial biogenesis-related markers and reduced lipid accumulation in adipocytes.The glycolipid metabolism pattern of K56 may be due to its immunomodulatory characteristics,which stimulated macrophages to secrete fewer TNF-α,thereby promoting the expression of lipolysis-related markers,and TNF-αsynergized with lipase to promote lipolysis.It has not been reported that L.paracasei modulated lipid metabolism via the lipolysis pathway,which suggested that K56 may regulate glycolipid metabolism of the host by maintaining immune homeostasis.
基金Supported by Special Project of"Grassland Talents"in Inner Mongolia.
文摘The rapid identification of lactic acid bacteria,which are essential microorganisms in the food industry,is of great significance for industrial applications.The identification of lactic acid bacteria traditionally relies on the isolation and identification of pure colonies.While this method is well-established and widely used,it is not without limitations.The subjective judgment inherent in the isolation and purification process introduces potential for error,and the incomplete nature of the isolation process can result in the loss of valuable information.The advent of next generation sequencing has provided a novel approach to the rapid identification of lactic acid bacteria.This technology offers several advantages,including rapidity,accuracy,high throughput,and low cost.Next generation sequencing represents a significant advancement in the field of DNA sequencing.Its ability to rapidly and accurately identify lactic acid bacteria strains in samples with insufficient information or in the presence of multiple lactic acid bacteria sets it apart as a valuable tool.The application of this technology not only circumvents the potential errors inherent in the traditional method but also provides a robust foundation for the expeditious identification of lactic acid bacteria strains and the authentication of bacterial powder in industrial applications.This paper commences with an overview of traditional and molecular biology methods for the identification of lactic acid bacteria.While each method has its own advantages,they are not without limitations in practical application.Subsequently,the paper provides an introduction of the principle,process,advantages,and disadvantages of next generation sequencing,and also details its application in strain identification and rapid identification of lactic acid bacteria.The objective of this study is to provide a comprehensive and reliable basis for the rapid identification of industrial lactic acid bacteria strains and the authenticity identification of bacterial powder.
文摘Microplastics are plastic particles or fibers with a diameter of less than 5 mm,and they widely exist in the environment and pose potential risks to the ecosystem and human health.Microplastics detection can provide basic data for formulating effective environmental protection strategies.In this paper,the physical,chemical and biological detection methods of microplastics are reviewed,and the advantages and disadvantages of different methods are analyzed.The problems and challenges encountered in microplastics detection are analyzed,and the future research is discussed.
文摘[Objectives]To verify the specificity,sensitivity,precision and negative-positive deviation of the foodproof gluten component de-tection kit for the detection of gluten allergens in milk powder matrix,and to establish a real-time fluorescent PCR legal method for the detec-tion of gluten allergens in milk powder.[Methods]The specificity,sensitivity,precision and negative-positive deviation of the detection method of foodproof gluten component detection kit(PCR-probe method)were verified by artificially adding different concentrations of wheat bran and extracting sample DNA by kit method,and applied to sample detection.[Results] The specific detection results of two kinds of milk powder with wheat bran and buckwheat added showed that the foodproof gluten component detection kit(PCR-probe method)had good speci-ficity for wheat gluten.The results of artificially added wheat bran positive samples showed that the false positive rate and false negative rate of the kit in the milk powder matrix were O,and the sensitivity and precision were high.[Conclusions]The kit is simple to operate and has high accuracy,which is suitable for the detection of gluten allergen components in milk powder.
文摘Microplastics pollution has become one of the focuses of global environmental science research.Microplastics include micro plastic particles and nano-plastic particles,which come from the decomposition of plastic products,the release of microfibers and the industrial process of plastic particles.The distribution of microplastics in water,soil and atmosphere is summarized,and the widespread existence of microplastics in different environmental media is emphasized.This paper also summarizes the potential impact of microplastics on ecosystems and organisms,and pays attention to the transmission and accumulation of microplastics in the food chain,as well as its potential threat to human health.Finally,the paper discusses the methods and technologies of microplastics treatment and monitoring at present,and puts forward the direction of further research on microplastics pollution in order to formulate more effective management and mitigation strategies.
基金Supported by Project of National Center of Technology Innovation for Dairy"Study on the Key Technologies of Microplastics Detection for New Pollutants in Dairy Ingredient Water"(2023-KFKT-24).
文摘As a new type of environmental pollutants,microplastics have gradually attracted people's attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and finally become microplastics.Microplastics can adsorb pollutants in the environment,and their components have certain toxicity,which can cause different degrees of harm to organisms.Due to the structural characteristics of microplastic particles,such as small particle size,large specific surface area,and their distribution in different environmental media,it is very difficult to accurately detect microplastics.Reliable collection and detection methods are the key to the study of environmental behavior of microplastics.In this study,the collection and detection methods of microplastics in the environment were reviewed,and the development direction of microplastics detection technology in the future was prospected.This study has a certain reference value for the related research and the prevention and treatment of micro-plastic pollution.
文摘In this paper,by combining sampling methods for food statistics with years of sample sampling experience,various sampling points and corresponding sampling methods are summarized.It hopes to discover food safety risks and improve the level of food safety.
基金supported by the National Natural Science Foundation of China(31871831,32172279)Liaoning Provincial Natural Science Foundation regional Joint Fund project(2020-MZLH-34)+1 种基金Shenyang City Youth Science and Technology Innovation Leading Talent Project(RC200495)Shenyang Science and technology innovation platform project(21-103-0-14,21-104-0-28).
文摘Pasteurized milk contains complex microbial communities affected by sterilization and storage conditions.This complex microflora may be the possible reason that pasteurized dairy products are highly prone to spoilage.In this study,packaged pasteurized milk products collected from dairy processing factories in China were stored at 0,4,10,15,and 25℃ for 0−15 days and subjected to microbial identification using high-throughput sequencing.Accordingly,6 phyla and 44 genera were identified as the dominant microbiota.Moreover,the changes in nutritional composition of the pasteurized milk,including in 16 free amino acids,7 taste values,and 8 chemical constituents,were analyzed using principal component and multi-factor analyses.The Pearson correlation analysis identified Pseudomonas,Aeromonas,Paenibacillus,and Serratia genera as the core functional microbiota that significantly affects the nutritional composition of pasteurized milk.Hence,the results provide a comprehensive understanding of the safety and shelf-life of stored pasteurized milk.
文摘[Objectives]The paper was to establish an evaluation method for the uncertainty of stevioside(including stevioside,rebaudioside A,rebaudioside B,rebaudioside C,rebaudioside F,Dulcoside A,rubusoside and steviolbioside)content determination in fermented milk based on HPLC.[Methods]The mathematical model of stevioside content and the propagation rate of uncertainty were established,and the sources of uncertainty were analyzed.[Results]The uncertainty mainly came from four main aspects,including standard uncertainty u(C)introduced by solution concentration C,standard uncertainty u(V)introduced by sample volume V,standard uncertainty u(m)introduced by sample mass m weighing and standard uncertainty u(f_(rep))introduced by measurement repeatability of stevioside content after sample dissolution and constant volume.The uncertainty estimation table and fishbone chart of stevioside content X determination were established.The relative synthetic standard uncertainty of stevioside content was obtained,and the standard uncertainty was extended to form the measurement result of stevioside content and its uncertainty report.[Conclusions]The evaluation results can be directly applied to the daily practical detection work.
基金Supported by Special Project of"Grassland Talents"in Inner Mongolia.
文摘[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA was extracted for amplification of 16S rDNA and gyrB gene.The 16S rDNA and gyrB gene sequences were obtained after sequencing.Sequences were aligned and analyzed via EzBioCloud and NCBI database,and phylogenetic trees were constructed to determine the species relationship of strains.Meantime,they were compared with known strains.[Results]This method could identify 5 standard strains accurately to the species level.The 16S rDNA and gyrB gene sequences were aligned and analyzed in EzBioCloud database and NCBI database.The strain with the max score was consistent with the known strain.And the query cover and ident were both above 99%.[Conclusions]The established molecular biological method for identification of bacterial strains by 16S rDNA and gyrB gene has good accuracy,which effectively solves the problem that the laboratory identification of bacteria relies on traditional methods and the accuracy can not be guaranteed,and further improves the identification ability of laboratory bacterial strains.
文摘As the global economy enters a new stage,Chinese dairy enterprises are gradually moving towards the road of internationalization.In this paper,the internationally common quality management system,food safety system and quality traceability system were analyzed and studied to promote the comprehensive transformation and upgrading of dairy industry and broaden the development road with the help of systematic construction.
文摘With the development of economy,people's living standards are constantly improving,and the requirements for food safety are getting higher and higher.The Food Safety Law stipulates that enterprises should implement the main responsibility of food safety,and the investigation and improvement of food safety hazards plays an important role in improving the food safety management level of enterprises and reducing food safety risks.This paper combines the innovative thinking mode of six thinking hats with food safety,discusses the application mode of six thinking hats in food safety investigation and improvement,and hopes to improve food safety level through this way.
文摘[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.
基金National Key R&D Program for the Thirteenth Five-Year Plan Period(2017YFE0110800).
文摘[Objectives]To determine the aerobic plate count(APC)in the milk samples,evaluate the uncertainty of the test results,and to provide a scientific basis for the quality control of the testing process.[Methods]In compliance with the national food safety standard Food Microbiological Examination:Aerobic Plate Count(GB 4789.2-2016),the aerobic plate count in the milk samples was detected.The source of the uncertainty of the test result was analyzed and a mathematical model was established in accordance with Evaluation and Expression of Uncertainty in Measurement(JJF 1059.1-2012).Then,the introduced uncertainty components were evaluated to determine the uncertainty of the final combined aerobic plate count.[Results]The expanded uncertainty of the test result of the aerobic plate count in the milk samples was 0.0434,and the logarithmic value interval of the results was(3.924,4.010),and the antilogarithm was taken to get the aerobic plate count in the sample to be 8395-10233 CFU/mL.[Conclusions]This method can effectively evaluate the uncertainty of the aerobic plate count,and ensure the accurate and scientific laboratory test data.
基金Supported by the Inner Mongolia Yili Industrial Group Co.Ltd.(Inner Mongolia Dairy Technology Research Institute Co.Ltd.)
文摘BACKGROUND Gastrointestinal(GI)discomforts are common in the elderly population;however,whether such discomforts are associated with dietary intake has not been studied.AIM To evaluate GI discomforts in Chinese urban elders and the associated factors.METHODS The gastrointestinal symptom rating scale(GSRS)was used to identify GI discomforts in 688 elders from eight cities of China.The semi-quantitative food frequency questionnaire and one time of 24 h dietary recall were used to access the food intake,identify dietary pattern,and calculate the nutrients intake.RESULTS About 83%of studied elders experienced at least one of GI discomforts in the past 6 mo;dyspepsia was the most commonly reported(66.7%),followed by reflux(44.8%),abdominal pain(35.9%),constipation(35.8%),and diarrhea(34.7%).Female gender,lower education level,and lower family income were associated with a higher GSRS score.Participants who were diagnosed with a GI-related disease had a higher score of constipation,but a lower score of reflux.Chronic diseases were positively associated with certain GI discomforts.Three dietary patterns were identified by the method of principal component analysis,which were characterized as high intake of salt and tea;more frequent intake of tubers,fruits,aquatic products,and soybeans;and high intake of cereal,vegetables,and meat,respectively.However,no associations between dietary patterns and GSRS score were found.The elders with a higher GSRS score had significantly lower intake of bean products.The elders whose GSRS score was≥21 and 18-20 decreased their bean production intake by 7.2(0.3,14.3)g/d and 14.3(1.2,27.3)g/d,respectively,compared with those who had a GSRS score≤17.There were no differences in other food categories,calories,or nutrients intake among elders with different GSRS scores.CONCLUSION GI discomforts are common in Chinese urban elders.GI discomforts might be associated with the choice of food.
文摘[Objectives]To accurately determine the naringin content in Rhizoma Drynariae.[Methods]The high performance liquid chromatography(HPLC)method was applied in the determination of the naringin content in Rhizoma Drynariae.The sample was sonicated at room temperature.The mobile phase was 0.1%phosphoric acid-acetonitrile(75∶25),detected by diode array detector at the wavelength of 284 nm,and quantified by external standard method.[Results]The linearity of naringin was good in the concentration range of 5-500μg/mL with a correlation coefficient of 0.9999.[Conclusions]This method has good linearity,easy operation,correctness and reproducibility as required,and is expected to provide a method for the determination of naringin content in Rhizoma Drynariae.
文摘[Objectives]To make simultaneous determination of vitamin K_(1)(VK_(1))and vitamin K_(2)(VK_(2),mainly MK-4,MK-7 and MK-9)in milk and dairy products.[Methods]A high performance liquid chromatographic method was developed for the simultaneous determination of vitamin K_(1)(VK_(1))and vitamin K_(2)(VK_(2),mainly MK-4,MK-7 and MK-9)in milk and dairy products.After enzymatic digestion,the samples were extracted with hexane for VK_(1),MK-4,MK-7 and MK-9,subjected to gradient elution at excitation wavelength 243 nm and emission wavelength 430 nm,detected by high performance liquid chromatography with fluorescence detector and quantified by external standard method.[Results]The linearity of VK_(1),MK-4,MK-7 and MK-9 was good in the concentration range of 2.5-1000 ng/mL with the correlation coefficients greater than 0.999;The relative standard deviations(RSD)of VK_(1),MK-4,MK-7 and MK-9 in milk powder,liquid milk and yogurt were 1.32%-5.05%,1.10%-2.48% and 2.20%-3.47%,respectively;the recovery rates of VK_(1),MK-4,MK-7 and MK-9 at different levels in milk powder,liquid milk and yogurt were 81.1%-108%,81.8%-103%and 82.1%-99.2%,respectively.[Conclusions]The method is rapid,accurate,reproducible and capable of simultaneous determination of VK_(1),MK-4,MK-7 and MK-9.
文摘In this paper,the six Aigma DMAIC method was used to systematically analyze and study the process affecting the good rate of blank value of cytological method for dairy products.Through data collection,analysis and verification in each link,the room for improvement in the experimental process was identified.C&E matrix and FMEA were used to analyze the factors affecting the good rate of blank value.Through the DOE experiment design method and risk analysis,the main influencing factors were optimized and improved.The optimized experimental conditions were:silica gel activation temperature(500±50)℃,activation time(23±1)h,cells adherent rate(95±1)%,and single-use of 1.5 mL conical flask.Under the above conditions,the good rate of blank value of cytological method was improved from 52.8%to 100%.The improvement of these conditions is of great significance to ensure the accuracy of results,save the testing cost and improve the testing efficiency.
基金Special Project of Inner Mongolia"Grassland Talents".
文摘[Objectives]To explore the inhibitory effect of lactic acid bacteria(LAB)on the growth of Salmonella.[Methods]The inhibitory effect of lactic acid bacteria on Salmonella was investigated by Oxford cup agar diffusion test from the aspects of lactic acid bacteria body,metabolites,pH,thermal stability and acid resistance.[Results]The growth of Salmonella was disturbed by the inhibition of lactic acid bacteria.The mechanism of inhibitory effect may be:simple low pH and lactic acid bacteria have no inhibitory effect on Salmonella;however,there are active substances in the metabolites of lactic acid bacteria,which have high thermal stability and a wide range of acid resistance,and are effective substances for inhibiting the growth of Salmonella.[Conclusions]This study is helpful for screening more natural preservative substances,reducing the contamination rate of Salmonella to food,and is expected to provide a theoretical basis for the preservation and preservation of food.
基金Supported by Special Project of "Grassland Talents" in Inner Mongolia
文摘[Objectives]To determine the content of organic pollutants by CALUX bioassay.[Methods]According to JJF 1059.1-2012 Technical Specification for Evaluation and Expression of Uncertainty in Measurement,the determination results of organic pollutants were analyzed,various sources of uncertainty that may be introduced in the detection process were analyzed,and the mathematical model of uncertainty was established.Type A and B evaluation methods were used to calculate the components of uncertainty and extended uncertainty.[Results]In the range of 95%confidence interval,the determination result of organic pollutants was 6.59 pg/g fat,and the extended uncertainty was 0.0764 pg/g fat,so the determination results of organic pollutants could be expressed as(6.59±0.0764)pg/g fat(k=2).[Conclusions]This study can provide a basis for more accurate determination of organic pollutants.
