Antioxidant and α-amylase inhibitory activities and starch hydrolysis kinetics of kidney bean by simulating digestion in vitro

Abstract

Objective: To evaluate the physiological effects of whole kidney been food and develop functional resources of different color kidney beans. Methods: The contents of total polyphenols, flavonoids and acid polysaccharides, and antioxidant and α-amylase inhibitory activities of digestive solution and starch hydrolysis kinetics and glucose diffusion properties of three kidney bean were investigated through in vitro simulated gastrointestinal digestion. Results: The contents of total polyphenols, flavonoids and acid polysaccharides, and antioxidant and α-amylase inhibitory activities were black kidney bean＞red kidney bean＞white kidney bean （P＜0.05）. The kinetic rate of first order reaction of starch hydrolysis, rapidly digestible starch contents and glucose diffusion rate were black kidney bean＜red kidney bean＜white kidney bean （P＜0.05）. Additionally, the contents of bioactive components of kidney bean digestive juices were positively correlated with the antioxidant activities, but negatively correlated with the rates of glucose diffusion （P＜0.05）. Conclusion: The digestive juices of kidney bean were rich in phenolic compounds and exhibited excellent antioxidant activity and certain α-amylase inhibitory ability.

Keywords

• kidney bean
• simulated digestion in vitro
• antioxidant
• α-amylase
• hydrolysis kinetics
• glucose diffusion