Pub Date : 2022-03-28DOI: 10.47866/2615-9252/vjfc.3884
Tu Vu Ngoc, Huong Hoang Lan, Tien Bui Cao, Son Tran Cao
High-resolution liquid chromatography-mass spectrometry (LC-HRMS) is a highly sensitive, specific and accurate method for the simultaneous detection and quantification of three mycotoxins Alternaria (Alternariol (AOH), Alternariol Monomethyl Ete) (AME), Tenuazonic acid (TeA)). Chromatographic conditions include: column reversed phase C18, mobile phases in gradient mode with two channels of H2O and MeOH containing 0.1 % formic acid and 10 mM ammonium formate. HRMS high resolution mass spectrometer detector with negative electron ionization (ESI-) source is used. Samples were cleaned and enriched using an Oasis HLB solid phase extraction column. The method has a limit of quantitation (LOQ) for AOH and AME of 1.0 µg/kg and TeA of 1.0 µg/kg with recovery from 80.0 to 114.8 %, repeatability from 0.07 - 9.9 %, meeting the requirements of AOAC and European regulations. The method was applied to detect and quantify Alternaria mycotoxins in 80 food samples collected in Hanoi city. AOH was detected in 04/20 vegetable samples (3.3 - 178 µg/kg), 03/20 fruit samples (5.6 - 7.3 µg/kg), 06/20 cereal samples (13.4 - 17.4 µg/kg), 03/20 oil seed samples (13.2 - 25.2 µg/kg); detected AME in 01/20 vegetable samples (7.5 µg/kg), 02/20 fruit samples (< 3 µg/kg), 01/20 cereal samples (9.5 µg/kg), 02/20 oil seed samples (< 3 µg/kg); detected TeA in 02/20 vegetable samples (9.0 µg/kg), 01/20 cereal samples (< 3 µg/kg), 02/20 oil seed samples (< 3 µg/kg), not detected in fruit samples.
{"title":"Development of method for determination and quantification of Alternaria mycotoxins in food by high resolution mass spectrometry","authors":"Tu Vu Ngoc, Huong Hoang Lan, Tien Bui Cao, Son Tran Cao","doi":"10.47866/2615-9252/vjfc.3884","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3884","url":null,"abstract":"High-resolution liquid chromatography-mass spectrometry (LC-HRMS) is a highly sensitive, specific and accurate method for the simultaneous detection and quantification of three mycotoxins Alternaria (Alternariol (AOH), Alternariol Monomethyl Ete) (AME), Tenuazonic acid (TeA)). Chromatographic conditions include: column reversed phase C18, mobile phases in gradient mode with two channels of H2O and MeOH containing 0.1 % formic acid and 10 mM ammonium formate. HRMS high resolution mass spectrometer detector with negative electron ionization (ESI-) source is used. Samples were cleaned and enriched using an Oasis HLB solid phase extraction column. The method has a limit of quantitation (LOQ) for AOH and AME of 1.0 µg/kg and TeA of 1.0 µg/kg with recovery from 80.0 to 114.8 %, repeatability from 0.07 - 9.9 %, meeting the requirements of AOAC and European regulations. The method was applied to detect and quantify Alternaria mycotoxins in 80 food samples collected in Hanoi city. AOH was detected in 04/20 vegetable samples (3.3 - 178 µg/kg), 03/20 fruit samples (5.6 - 7.3 µg/kg), 06/20 cereal samples (13.4 - 17.4 µg/kg), 03/20 oil seed samples (13.2 - 25.2 µg/kg); detected AME in 01/20 vegetable samples (7.5 µg/kg), 02/20 fruit samples (< 3 µg/kg), 01/20 cereal samples (9.5 µg/kg), 02/20 oil seed samples (< 3 µg/kg); detected TeA in 02/20 vegetable samples (9.0 µg/kg), 01/20 cereal samples (< 3 µg/kg), 02/20 oil seed samples (< 3 µg/kg), not detected in fruit samples.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88935872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-17DOI: 10.47866/2615-9252/vjfc.3906
D. Bui Quang, Ivanova Arina, Qiu Siyuan, Lanekoff Ingela
A simple and rapid capillary electrophoresis method with direct ultraviolet (UV) detection was set up for the determination of four organic acids in beverages. The method included dilution and filtration as simple sample preparation steps. The electrophoretic separation and detection of oxalic, malic, citric and lactic acids in wines and beers were performed in 8 min. For the method validation, linearity, detection and quantification limits, repeatability and recovery in wine and beer matrices were studied. Good linearity was observed from 25 to 500 mg/L for all acids excluding lactic acid, for which it started from 50 mg/L. The limits of quantitation of oxalic, malonic and citric acid were set 9.5 to 28.5 mg/L. Repeatability of this method was from 3.2 to 7.3%, recoveries ranged from 90.1 to 110.1%. The validated method was applied to the analysis of different wines and beers and showed great variability in their composition.
{"title":"Simultaneous determination of four organic acids in beverages by capillary electrophoresis coupled with ultraviolet detector","authors":"D. Bui Quang, Ivanova Arina, Qiu Siyuan, Lanekoff Ingela","doi":"10.47866/2615-9252/vjfc.3906","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3906","url":null,"abstract":"A simple and rapid capillary electrophoresis method with direct ultraviolet (UV) detection was set up for the determination of four organic acids in beverages. The method included dilution and filtration as simple sample preparation steps. The electrophoretic separation and detection of oxalic, malic, citric and lactic acids in wines and beers were performed in 8 min. For the method validation, linearity, detection and quantification limits, repeatability and recovery in wine and beer matrices were studied. Good linearity was observed from 25 to 500 mg/L for all acids excluding lactic acid, for which it started from 50 mg/L. The limits of quantitation of oxalic, malonic and citric acid were set 9.5 to 28.5 mg/L. Repeatability of this method was from 3.2 to 7.3%, recoveries ranged from 90.1 to 110.1%. The validated method was applied to the analysis of different wines and beers and showed great variability in their composition.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85763996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.47866/2615-9252/vjfc.3908
Minh Hoa Nguyen Thi, Hien Dang Thi, Hong Ngoc Nguyen Thi, Son Tran Cao, Thanh Hien Kim Thi, Thanh Ha Pham Thi
LC-MS/MS method providing high sensitivity for determination of five aristolochic acids (AA) and four aristolactams (AL) was built. Samples were extracted efficiently in Methanol: DMSO solvent. The detection limit of AA A, AL BII is 0.030 ng/g, of AL FI, AL AII is 0.15 ng/g, and of AA B, AA C, AA D, 7-OH AA A, AL I is 3.0 ng/g. Recoveries of nine target compounds were from 80.2 to 110%, and relative standard deviations were below 10.5%. The method was applied to simultaneously determine the content of nine target analytes in capsule, tablet, traditional round pill, and liquid herbal supplements collected from different drug stores in Hanoi, Vietnam. Results show that AA A, 7-OH AAA, and AL I compounds exist in 24 out of 30 health supplements. Among them, it is worth noting that three tablet samples without declaring ingredients belonged to Aristolochiaceae plants on the pack, but still be positive with AA A and AL I.
建立了测定5种马兜铃酸(AA)和4种马兜铃内酰胺(AL)的高灵敏度LC-MS/MS方法。样品在甲醇:DMSO溶剂中高效提取。AA、AL BII的检出限为0.030 ng/g, AL FI、AL AII的检出限为0.15 ng/g, AA B、AA C、AA D、7-OH AA、AL I的检出限为3.0 ng/g。9个目标化合物的加样回收率在80.2 ~ 110%之间，相对标准偏差在10.5%以下。采用该方法同时测定了从越南河内市不同药店采购的胶囊、片剂、传统圆丸和药液中9种目标物的含量。结果表明，30种保健品中有24种含有AAA、7-OH AAA和AL I化合物。其中，值得注意的是，有3个片剂样品在包装上未注明成分属马兜铃科植物，但仍检测出AA A和AL I阳性。
{"title":"Determination of some Aristolochic acid and Aristolactam in herbal dietary supplements containing Aristolochiaceae plants","authors":"Minh Hoa Nguyen Thi, Hien Dang Thi, Hong Ngoc Nguyen Thi, Son Tran Cao, Thanh Hien Kim Thi, Thanh Ha Pham Thi","doi":"10.47866/2615-9252/vjfc.3908","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3908","url":null,"abstract":"LC-MS/MS method providing high sensitivity for determination of five aristolochic acids (AA) and four aristolactams (AL) was built. Samples were extracted efficiently in Methanol: DMSO solvent. The detection limit of AA A, AL BII is 0.030 ng/g, of AL FI, AL AII is 0.15 ng/g, and of AA B, AA C, AA D, 7-OH AA A, AL I is 3.0 ng/g. Recoveries of nine target compounds were from 80.2 to 110%, and relative standard deviations were below 10.5%. The method was applied to simultaneously determine the content of nine target analytes in capsule, tablet, traditional round pill, and liquid herbal supplements collected from different drug stores in Hanoi, Vietnam. Results show that AA A, 7-OH AAA, and AL I compounds exist in 24 out of 30 health supplements. Among them, it is worth noting that three tablet samples without declaring ingredients belonged to Aristolochiaceae plants on the pack, but still be positive with AA A and AL I.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77361268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-09DOI: 10.47866/2615-9252/vjfc.3882
Phuong Thao Le Thi, Hang Nguyen Thi, Hong Ha Tran Thi, Chau Nguyen Minh
Reference materials are an important tool in ensuring the validity of testing results. The use of standard materials in Vietnam is currently limited because the supply depends on foreign standard material manufacturers at a high cost, and there is no domestic manufacturer for water and food reference materials production. This study aims to provide a procedure reference materials production for heavy metals Pb, Cd, As, and Hg analysis in water. The reference materials were homogenized and stable for a period of 318 days from the date of manufacture. With the assigned values consistent with the concentration to be analyzed of the heavy metals in the normal water sample. The measurement uncertainty ranges from 7.0 to 21.7 %. These reference materials can be used for internal quality control for laboratories. The research provides a standard procedure for the following production times for reference materials for heavy metal analysis in water and also a premise for further research on standard samples with matrix and other analytical criteria.
{"title":"Study on the Production of Reference Material of Heavy Metals (As, Cd, Pb, Hg) in Water","authors":"Phuong Thao Le Thi, Hang Nguyen Thi, Hong Ha Tran Thi, Chau Nguyen Minh","doi":"10.47866/2615-9252/vjfc.3882","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3882","url":null,"abstract":"Reference materials are an important tool in ensuring the validity of testing results. The use of standard materials in Vietnam is currently limited because the supply depends on foreign standard material manufacturers at a high cost, and there is no domestic manufacturer for water and food reference materials production. This study aims to provide a procedure reference materials production for heavy metals Pb, Cd, As, and Hg analysis in water. The reference materials were homogenized and stable for a period of 318 days from the date of manufacture. With the assigned values consistent with the concentration to be analyzed of the heavy metals in the normal water sample. The measurement uncertainty ranges from 7.0 to 21.7 %. These reference materials can be used for internal quality control for laboratories. The research provides a standard procedure for the following production times for reference materials for heavy metal analysis in water and also a premise for further research on standard samples with matrix and other analytical criteria.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87431832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-03DOI: 10.47866/2615-9252/vjfc.3901
Thanh Nga Nguyen Thi, Hung Long Nguyen, Nhung Ninh Thi, Kieu Chinh Pham Thi
The current situation of the Covid-19 epidemic is still complicated, ensuring food safety for food service businesses is very important and necessary. The study conducted to assess the facility conditions, equipment and materials to ensure food safety at 61 food service businesses to prevent Covid-19 epidemic in Son La City in 2020 showed that 100% of the processing areas of establishments with a place to wash hands, clean water and soap, fully equipped with food preservation equipment, and clean daily waste collection. However, only 29.5% of establishments arrange kitchen on the principle of one-way. 100% of establishments meet the conditions on equipment and tools. Over 80% of establishments arrange to eat in several shifts to ensure the distance and enough tables and chairs with barriers to separate and arrange the distance between customers. 100% of establishments have communication posters about Covid 19 in the dining area.
{"title":"Facility conditions, equipment, and materials to ensure food safety at food service establishments to prevent Covid-19 epidemic in Son La city in 2020","authors":"Thanh Nga Nguyen Thi, Hung Long Nguyen, Nhung Ninh Thi, Kieu Chinh Pham Thi","doi":"10.47866/2615-9252/vjfc.3901","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3901","url":null,"abstract":"The current situation of the Covid-19 epidemic is still complicated, ensuring food safety for food service businesses is very important and necessary. The study conducted to assess the facility conditions, equipment and materials to ensure food safety at 61 food service businesses to prevent Covid-19 epidemic in Son La City in 2020 showed that 100% of the processing areas of establishments with a place to wash hands, clean water and soap, fully equipped with food preservation equipment, and clean daily waste collection. However, only 29.5% of establishments arrange kitchen on the principle of one-way. 100% of establishments meet the conditions on equipment and tools. Over 80% of establishments arrange to eat in several shifts to ensure the distance and enough tables and chairs with barriers to separate and arrange the distance between customers. 100% of establishments have communication posters about Covid 19 in the dining area.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90058906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-03DOI: 10.47866/2615-9252/vjfc.3879
Thanh Nga Nguyen Thi, Long Nguyen Hung, Nhung Ninh Thi, Kieu Chinh Pham Thi
The current situation of the Covid-19 epidemic is still complicated, ensuring food safety for food service businesses is extremely necessary. Research and evaluate knowledge and practice on food safety of establishment owners, food processors and customers to prevent Covid-19 epidemic at food service establishments in Son La city in 2020 for found that the results were quite high: over 75 % of owners had knowledge of regulations to ensure food safety in the prevention of Covid-19 epidemic and 100 % were trained in disseminating and guiding epidemic prevention documents. Food processors who have knowledge and practice of regulations on ensuring food safety to prevent Covid-19 have reached a high rate of over 90 %, especially regulations of the Ministry of Health such as wearing masks when working, keep contact distance; wash hands, disinfect properly, and do not gather in large numbers in production facilities. 100 % of customers know about the 5K message. It is necessary to further strengthen the propaganda to ensure food safety to prevent Covid-19 epidemic so that the subjects can better understand the regulations of the Government, the Ministry of Health, departments and branches on ensuring food safety and prevention. Covid-19 and good practice of the above regulations.
{"title":"Knowledge and practice of food safety of establishment owners, food processors, and customers to prevent Covid-19 epidemic at food service businesses in Son La city in 2020","authors":"Thanh Nga Nguyen Thi, Long Nguyen Hung, Nhung Ninh Thi, Kieu Chinh Pham Thi","doi":"10.47866/2615-9252/vjfc.3879","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3879","url":null,"abstract":"The current situation of the Covid-19 epidemic is still complicated, ensuring food safety for food service businesses is extremely necessary. Research and evaluate knowledge and practice on food safety of establishment owners, food processors and customers to prevent Covid-19 epidemic at food service establishments in Son La city in 2020 for found that the results were quite high: over 75 % of owners had knowledge of regulations to ensure food safety in the prevention of Covid-19 epidemic and 100 % were trained in disseminating and guiding epidemic prevention documents. Food processors who have knowledge and practice of regulations on ensuring food safety to prevent Covid-19 have reached a high rate of over 90 %, especially regulations of the Ministry of Health such as wearing masks when working, keep contact distance; wash hands, disinfect properly, and do not gather in large numbers in production facilities. 100 % of customers know about the 5K message. It is necessary to further strengthen the propaganda to ensure food safety to prevent Covid-19 epidemic so that the subjects can better understand the regulations of the Government, the Ministry of Health, departments and branches on ensuring food safety and prevention. Covid-19 and good practice of the above regulations.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88245716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.47866/2615-9252/vjfc.3883
Cong Cuu Nguyen, T. Phan, Q. T. Le, Thanh Huong Le Thi, Tuyet Hanh Tran Thi, Toan Luu Quoc
Pesticides have taken an important role and they have had popular use in agricultural cultivation. However, that may increase the risk of pesticide residues in agricultural products. Cross-sectional study, using secondary data on monitoring of pesticide residues on the agricultural products in Dong Thap province during 2016-2017. The study was carried out from October to December 2019. The results show in 2016, the percentage of vegetables and fruits in Dong Thap province with pesticide residues was counted as 12.1 % and 5.3 %, respectively; in 2017 were 29.4 % and 5.6 %, respectively. However, the concentration of pesticide residues on vegetable and fruit samples was found to be mostly under the allowable threshold as prescribed by the Ministry of Health. The monitoring of pesticide residues on agricultural products is a necessary activity to improve the quality of agricultural products and the safety of the community's health.
{"title":"Pesticide residues on the agricultural products in Dong Thap province during 2016 - 2017","authors":"Cong Cuu Nguyen, T. Phan, Q. T. Le, Thanh Huong Le Thi, Tuyet Hanh Tran Thi, Toan Luu Quoc","doi":"10.47866/2615-9252/vjfc.3883","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3883","url":null,"abstract":"Pesticides have taken an important role and they have had popular use in agricultural cultivation. However, that may increase the risk of pesticide residues in agricultural products. Cross-sectional study, using secondary data on monitoring of pesticide residues on the agricultural products in Dong Thap province during 2016-2017. The study was carried out from October to December 2019. The results show in 2016, the percentage of vegetables and fruits in Dong Thap province with pesticide residues was counted as 12.1 % and 5.3 %, respectively; in 2017 were 29.4 % and 5.6 %, respectively. However, the concentration of pesticide residues on vegetable and fruit samples was found to be mostly under the allowable threshold as prescribed by the Ministry of Health. The monitoring of pesticide residues on agricultural products is a necessary activity to improve the quality of agricultural products and the safety of the community's health.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91212821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-01DOI: 10.47866/2615-9252/vjfc.3881
Nuong Nguyen Kim, Ngoc Mai Dinh Thi, Hieu Vo Hoai, Huong Le Thi, Hue Pham Thi, Hanh Ninh Thi, Hoa Le Vinh, Q. Pham Van, H. Nguyen
Strawberries are economically important owing to their unique flavour, health benefits, and nutritional aspects. Decay after harvest is a major issue in the development of strawberry industry. Currently, the most effective method for controlling decay after harvest is storage of strawberries at low temperature combined with usage of chemical fungicides. However, long-term usage of chemical fungicides not only causes pathogen resistance but also is harmful for human health and environment. Biocontrol method for the management of disease after strawberry harvest has great practical significance. In this study, totally 200 bacterial strains isolated from the surface of healthy strawberry fruit were tested for antagonistic activity against five fungal pathogens. Among them, VK199 strain was potent against all five postharvest spoilage fungi on strawberry fruit and then utilized for further study. This strain was identified as Bacillus siamensis based on sequence analysis of 16S rDNA. The extracellular lytic enzymes, including cellulase, amylase, protease and chitinase released by B. siamensis VK199 were detected. Furthemore, in vivo, the results of biological control efficacy test showed that B. siamensis VK199 suppressed the occurrence of diseases caused by Botrytis cinerea, Colletotrichum gloeosporioides, Mucor nidicola and Rhizopus delemar of strawberry during storage.
{"title":"Selection and identification of potential bacteria against postharvest fungal pathogens on strawberry fruit","authors":"Nuong Nguyen Kim, Ngoc Mai Dinh Thi, Hieu Vo Hoai, Huong Le Thi, Hue Pham Thi, Hanh Ninh Thi, Hoa Le Vinh, Q. Pham Van, H. Nguyen","doi":"10.47866/2615-9252/vjfc.3881","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3881","url":null,"abstract":"Strawberries are economically important owing to their unique flavour, health benefits, and nutritional aspects. Decay after harvest is a major issue in the development of strawberry industry. Currently, the most effective method for controlling decay after harvest is storage of strawberries at low temperature combined with usage of chemical fungicides. However, long-term usage of chemical fungicides not only causes pathogen resistance but also is harmful for human health and environment. Biocontrol method for the management of disease after strawberry harvest has great practical significance. In this study, totally 200 bacterial strains isolated from the surface of healthy strawberry fruit were tested for antagonistic activity against five fungal pathogens. Among them, VK199 strain was potent against all five postharvest spoilage fungi on strawberry fruit and then utilized for further study. This strain was identified as Bacillus siamensis based on sequence analysis of 16S rDNA. The extracellular lytic enzymes, including cellulase, amylase, protease and chitinase released by B. siamensis VK199 were detected. Furthemore, in vivo, the results of biological control efficacy test showed that B. siamensis VK199 suppressed the occurrence of diseases caused by Botrytis cinerea, Colletotrichum gloeosporioides, Mucor nidicola and Rhizopus delemar of strawberry during storage.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72795471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-25DOI: 10.47866/2615-9252/vjfc.3880
Mai Huong Pham Thi, My Hanh Truong Thi, Huyen My Dang Thi, Trang Vu Thi, Khanh Cao Cong, Anh Hoang Quoc, Ngoc Anh Mai Thi, Minh Thu Nguyen Thi, Quang Huy Nguyen, Anh Huong Nguyen Thi
A simple, rapid and specific method using high performance liquid chromatography with fluorescence detector (HPLC-FLD) was developed for quantification of glucosamine in supplements after derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). The chromatographic separation was achieved on a C18 column (150 mm × 4.6 mm × 5 µm) using a gradient mobile phase containing acetonitrile and water at a flow rate of 1.0 mL/min. The FLD detector was operated at excitation and emission wavelengths of 265 and 315 nm, respectively. The analytical method was validated for specificity, linearity, accuracy, and precision. The detector response for glucosamine was linear over the selected concentration range from 6.7 to 135 ppm with a correlation coefficient of 0.9988. The repeatability (RSD, n = 6) and reproducibility (RSD, n = 4) were from 2.54 to 3.23 % and from 2.24 to 3.07 %, respectively. The recovery was between 98.0 and 101.5 %. In addition, we also joined the interlaboratory proficiency testing program (code: H21.11) organized by the National Institute of Food Control with good result (z-score value was - 0.89 < 2). The method was successfully applied for the analysis of glucosamine in 15 supplement samples.
建立了一种高效液相色谱-荧光检测器(HPLC-FLD)定量9-氟酰氯甲酸甲酯(FMOC-Cl)衍生后营养补充品中氨基葡萄糖的方法。色谱分离采用C18色谱柱(150 mm × 4.6 mm × 5µm)，梯度流动相含乙腈和水，流速为1.0 mL/min。FLD检测器的激发波长为265 nm，发射波长为315 nm。验证了分析方法的专属性、线性度、准确度和精密度。在6.7 ~ 135 ppm范围内，葡萄糖胺的检测响应呈线性关系，相关系数为0.9988。重复性(RSD, n = 6)和重现性(RSD, n = 4)分别为2.54 ~ 3.23%和2.24 ~ 3.07%。回收率在98.0% ~ 101.5%之间。此外，我们还参加了国家食品控制研究所组织的实验室间能力测试项目(代码:H21.11)，结果良好(z-score值为- 0.89 < 2)。该方法成功应用于15份补充剂样品的葡萄糖胺分析。
{"title":"Determination of glucosamine in functional food samples by high performance liquid chromatography (HPLC-FLD)","authors":"Mai Huong Pham Thi, My Hanh Truong Thi, Huyen My Dang Thi, Trang Vu Thi, Khanh Cao Cong, Anh Hoang Quoc, Ngoc Anh Mai Thi, Minh Thu Nguyen Thi, Quang Huy Nguyen, Anh Huong Nguyen Thi","doi":"10.47866/2615-9252/vjfc.3880","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3880","url":null,"abstract":"A simple, rapid and specific method using high performance liquid chromatography with fluorescence detector (HPLC-FLD) was developed for quantification of glucosamine in supplements after derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). The chromatographic separation was achieved on a C18 column (150 mm × 4.6 mm × 5 µm) using a gradient mobile phase containing acetonitrile and water at a flow rate of 1.0 mL/min. The FLD detector was operated at excitation and emission wavelengths of 265 and 315 nm, respectively. The analytical method was validated for specificity, linearity, accuracy, and precision. The detector response for glucosamine was linear over the selected concentration range from 6.7 to 135 ppm with a correlation coefficient of 0.9988. The repeatability (RSD, n = 6) and reproducibility (RSD, n = 4) were from 2.54 to 3.23 % and from 2.24 to 3.07 %, respectively. The recovery was between 98.0 and 101.5 %. In addition, we also joined the interlaboratory proficiency testing program (code: H21.11) organized by the National Institute of Food Control with good result (z-score value was - 0.89 < 2). The method was successfully applied for the analysis of glucosamine in 15 supplement samples.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79337503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-23DOI: 10.47866/2615-9252/vjfc.3849
D. Pham, Hang Nguyen Thi, Ly Nguyễn Thị, Minh Huyen Nguyen Thi
Phellinus linteus strain GC was cultured for harvesting biomass by submerged fermentation method in 100 L fermenter which produced in Vietnam. The process of cultivation of this fungus was performed in aerobic conditions with aeration at 1 vvm, stirred at 150 rpm, temperature from 27oC to 29oC. The observation of cultivation was performed to evaluate the optimum time of growth which produce highest biomass of the mycelium for application purpose of using as functional food. The pH of medium was slightly changed with decrease then increase again, and reached about 6.0 when cultivation process ends. The biomass of mycelium was gradually increased until about 11 days of cultivation with about 30 g/L of dried biomass and the content of of sugar reduced in medium decreased from 40 g/L to 6 g/L.
{"title":"A report on characterization of submerged fermentation of Phellinus linteus in Vietnam","authors":"D. Pham, Hang Nguyen Thi, Ly Nguyễn Thị, Minh Huyen Nguyen Thi","doi":"10.47866/2615-9252/vjfc.3849","DOIUrl":"https://doi.org/10.47866/2615-9252/vjfc.3849","url":null,"abstract":"Phellinus linteus strain GC was cultured for harvesting biomass by submerged fermentation method in 100 L fermenter which produced in Vietnam. The process of cultivation of this fungus was performed in aerobic conditions with aeration at 1 vvm, stirred at 150 rpm, temperature from 27oC to 29oC. The observation of cultivation was performed to evaluate the optimum time of growth which produce highest biomass of the mycelium for application purpose of using as functional food. The pH of medium was slightly changed with decrease then increase again, and reached about 6.0 when cultivation process ends. The biomass of mycelium was gradually increased until about 11 days of cultivation with about 30 g/L of dried biomass and the content of of sugar reduced in medium decreased from 40 g/L to 6 g/L.","PeriodicalId":12896,"journal":{"name":"Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78079966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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