Tea polyphenols is a natural antioxidant with a variety of biological activity.However,the weak liposolubility and low bioavailability limit their application.As a result,structural modification of tea polyphenols com...Tea polyphenols is a natural antioxidant with a variety of biological activity.However,the weak liposolubility and low bioavailability limit their application.As a result,structural modification of tea polyphenols comes into being.The prepared liposoluble tea polyphenols was suggested as a good candidate antioxidant for edible-oil and fats products.But,safety studies on liposoluble tea polyphenols are limited.The objective of the present study was conducted to synthesize liposoluble tea polyphenols and evaluate its toxicity in Sprague-Dawley rats on oral administration at dietary levels of 1,2 and 4% for 30 days.There were no adverse effects on general condition,growth,food intake,feed conversion efficiency,haematology parameters,clinical chemistry values and organ weights.High-dose males exhibited a higher haemoglobin concentration and a lower alanine aminotransferase levels,and high-dose females showed a lower albumin and globulin levels.These slight changes were considered of no toxicological significance.Necropsy and histopathology findings revealed no treatment-related changes in any of the organs.Thus,the results allowed us to conclude that the liposoluble tea polyphenols properly utilized in the oral administration could be devoid of any toxic risk.展开更多
Tea Polysaccharides(TPS) has been acknowledged of one of the most important components with various bioactivities in tea.The extraction of TPS from wide tea sources was the previous and determinant work before further...Tea Polysaccharides(TPS) has been acknowledged of one of the most important components with various bioactivities in tea.The extraction of TPS from wide tea sources was the previous and determinant work before further studies done.While the extraction procedures of TPS would be different due to the later utilization.In this work,the extraction conditions of TPS were previously optimized by respond surface methodology.A quadric model was obtained as Y = 3.16 + 0.31X1- 0.55X2- 0.47X3- 0.034X1X2+ 0.022X1X3- 0.041X2X3- 0.90X12-0.40X22- 0.73X32.The model was tested and proved through the ANOVA with F-value and p-value.Furthermore,the optimal condition was achieved as extraction temperature of 82℃,extraction time of 106 min and ratio of water to material of 33∶ 1(mL/g),meanwhile the highest yield of TPS showed 3.39% ± 0.08%.The crude TPS was later refined to be of purity of 81.3%.The refined TPS was incorporated with starch as to state the role of TPS in the starch retrogradation of starch-based food.The results showed that TPS-wheat starch mixture has a relatively low degree of retrogradation,which indicated that TPS has a delayed or resistant effect on wheat starch retrogradation.This work may provide a practical evidence for the promising starch-based food incorporated tea.展开更多
基金Project of the National Twelfth-Five Year Research Program of China(2012BAD36B06)
文摘Tea polyphenols is a natural antioxidant with a variety of biological activity.However,the weak liposolubility and low bioavailability limit their application.As a result,structural modification of tea polyphenols comes into being.The prepared liposoluble tea polyphenols was suggested as a good candidate antioxidant for edible-oil and fats products.But,safety studies on liposoluble tea polyphenols are limited.The objective of the present study was conducted to synthesize liposoluble tea polyphenols and evaluate its toxicity in Sprague-Dawley rats on oral administration at dietary levels of 1,2 and 4% for 30 days.There were no adverse effects on general condition,growth,food intake,feed conversion efficiency,haematology parameters,clinical chemistry values and organ weights.High-dose males exhibited a higher haemoglobin concentration and a lower alanine aminotransferase levels,and high-dose females showed a lower albumin and globulin levels.These slight changes were considered of no toxicological significance.Necropsy and histopathology findings revealed no treatment-related changes in any of the organs.Thus,the results allowed us to conclude that the liposoluble tea polyphenols properly utilized in the oral administration could be devoid of any toxic risk.
基金supported by the National Key Technology R&D Program (2012BAD36B06)
文摘Tea Polysaccharides(TPS) has been acknowledged of one of the most important components with various bioactivities in tea.The extraction of TPS from wide tea sources was the previous and determinant work before further studies done.While the extraction procedures of TPS would be different due to the later utilization.In this work,the extraction conditions of TPS were previously optimized by respond surface methodology.A quadric model was obtained as Y = 3.16 + 0.31X1- 0.55X2- 0.47X3- 0.034X1X2+ 0.022X1X3- 0.041X2X3- 0.90X12-0.40X22- 0.73X32.The model was tested and proved through the ANOVA with F-value and p-value.Furthermore,the optimal condition was achieved as extraction temperature of 82℃,extraction time of 106 min and ratio of water to material of 33∶ 1(mL/g),meanwhile the highest yield of TPS showed 3.39% ± 0.08%.The crude TPS was later refined to be of purity of 81.3%.The refined TPS was incorporated with starch as to state the role of TPS in the starch retrogradation of starch-based food.The results showed that TPS-wheat starch mixture has a relatively low degree of retrogradation,which indicated that TPS has a delayed or resistant effect on wheat starch retrogradation.This work may provide a practical evidence for the promising starch-based food incorporated tea.
