An experiment was conducted to investigate the effect of different initial pH on the storage characteristics and shelf life of liquid diet. 45 polypropylene bags were allotted to treatments 1, 2 and 3 on average, 100 ...An experiment was conducted to investigate the effect of different initial pH on the storage characteristics and shelf life of liquid diet. 45 polypropylene bags were allotted to treatments 1, 2 and 3 on average, 100 g diet and 200 g water were placed into each polypropylene bag, food-grade DL-lactic acid was added to each bag at a rate of 0.0 mL in treatment l, 1.2 mL in treatment 2 and 4.7 mL in treatment 3, air was artificially expelled from each bag prior to heat-sealing. All bags were placed into a cage, cooked with steam at 90~C for 30 rain under normal pressure, then taken out and stored from day 0 to 60 at room temperature. Results indicated that liquid diet in treatment 3 achieved the highest total sensory scores, the pH value had a tendency to decrease and the bacteria count had a tendency to increase in the liquid diet with the advancing of storage time with the advancing of storage time, lowering the initial pH of liquid diet decreased the bacteria count, the AFBl and ZEN concentrations and increased the starch gelatinization degree from day 30 to 60, liquid diet in treatment 3 had a lower （P〈0.01） bacteria count and a higher （P〈0.05） starch gelatinization degree at day 30 and 45 than liquid diet in treatment 1. In conclusion, lowering the initial pH of liquid diet with lactic acid to pH 4 could effectively improve the storage characteristics and shelf life of liquid diet.展开更多
Urine is a human biofluid that is widely used for metabolomics research on disease biomarker discovery.Ideally,the metabolome profiles generated from comparative groups of individuals should mainly consist of the endo...Urine is a human biofluid that is widely used for metabolomics research on disease biomarker discovery.Ideally,the metabolome profiles generated from comparative groups of individuals should mainly consist of the endogenous human metabolites that reflect the healthy states of the individuals.However,external factors,such as diet,may alter the urine metabolome profile by either introducing a significant amount or variety of exogenous metabolites to urine or inducing changes of the metabolome profile.Thus,strict control of the external factors during the sample collection process is critical for urine metabolomics aimed at discovery of disease biomarkers.In this work,we describe a study to determine the effect of drinking Goji tea,which is considered a nutritional supplement drink in some regions of the world,on urine metabolome profile.The purpose of this work is not to determine the nutritional values of Goji tea,but to investigate whether drinking a moderate amount of Goji tea 1-3 h(short-term effect)or 12 h(longer-term effect)before urine collection can cause significant variations of urine metabolome profiles.A highly sensitive dansylation isotope labeling liquid chromatography mass spectrometry(LC-MS)method was used to determine the urine metabolomes before and after drinking Goji tea.From the studies of the short term(<3 h)and longer term(12 h)effects of drinking Goji tea,it is clear that the consumption of a moderate amount of Goji tea does not affect the urine metabolome significantly.Fasting for 12 h should be sufficient to remove any potential interference of Goji metabolites from the human urine metabolome profile.展开更多
基金supported by the Jiangxi Key Technology R&D Program,China(2010CCA01300,20121BBF60032)
文摘An experiment was conducted to investigate the effect of different initial pH on the storage characteristics and shelf life of liquid diet. 45 polypropylene bags were allotted to treatments 1, 2 and 3 on average, 100 g diet and 200 g water were placed into each polypropylene bag, food-grade DL-lactic acid was added to each bag at a rate of 0.0 mL in treatment l, 1.2 mL in treatment 2 and 4.7 mL in treatment 3, air was artificially expelled from each bag prior to heat-sealing. All bags were placed into a cage, cooked with steam at 90~C for 30 rain under normal pressure, then taken out and stored from day 0 to 60 at room temperature. Results indicated that liquid diet in treatment 3 achieved the highest total sensory scores, the pH value had a tendency to decrease and the bacteria count had a tendency to increase in the liquid diet with the advancing of storage time with the advancing of storage time, lowering the initial pH of liquid diet decreased the bacteria count, the AFBl and ZEN concentrations and increased the starch gelatinization degree from day 30 to 60, liquid diet in treatment 3 had a lower （P〈0.01） bacteria count and a higher （P〈0.05） starch gelatinization degree at day 30 and 45 than liquid diet in treatment 1. In conclusion, lowering the initial pH of liquid diet with lactic acid to pH 4 could effectively improve the storage characteristics and shelf life of liquid diet.
基金supported by the Natural Sciences and Engineering Research Council of Canadathe Canadian Institutes of Health Research+1 种基金the Canada Research Chairs ProgramGenome Canada
文摘Urine is a human biofluid that is widely used for metabolomics research on disease biomarker discovery.Ideally,the metabolome profiles generated from comparative groups of individuals should mainly consist of the endogenous human metabolites that reflect the healthy states of the individuals.However,external factors,such as diet,may alter the urine metabolome profile by either introducing a significant amount or variety of exogenous metabolites to urine or inducing changes of the metabolome profile.Thus,strict control of the external factors during the sample collection process is critical for urine metabolomics aimed at discovery of disease biomarkers.In this work,we describe a study to determine the effect of drinking Goji tea,which is considered a nutritional supplement drink in some regions of the world,on urine metabolome profile.The purpose of this work is not to determine the nutritional values of Goji tea,but to investigate whether drinking a moderate amount of Goji tea 1-3 h(short-term effect)or 12 h(longer-term effect)before urine collection can cause significant variations of urine metabolome profiles.A highly sensitive dansylation isotope labeling liquid chromatography mass spectrometry(LC-MS)method was used to determine the urine metabolomes before and after drinking Goji tea.From the studies of the short term(<3 h)and longer term(12 h)effects of drinking Goji tea,it is clear that the consumption of a moderate amount of Goji tea does not affect the urine metabolome significantly.Fasting for 12 h should be sufficient to remove any potential interference of Goji metabolites from the human urine metabolome profile.
