The Effect Of Gluten,Different Particle Size And Tea Polyphenols On The Digestion Of Starch

The rapid rate of starch digestion can cause the body to have an increased risk of metabolic diseases.Slowing down the rate in food,as well as controling postprandial blood glucose and keeping energy balance is one of the effective ways to alleviate the rapid increase in the number of people suffering from the diseases.The digestion rate is affected by the size of the material and finished product,the presence of proteins and polyphenols,etc.This study provided a better understanding for starchy food and materials granules particle size and gluten influence on noodles morphology,structural characteristics,physicochemical properties and starch digestion rate and extent though using electron scanning microscopy,confocal laser scanning microscopy,differential scanning calorimetry,X-ray diffraction and the digestion logarithm of the slope(LOS)model.The interactions between starch,protein and tea polyphenols affected the digestion rate and degree and physicochemical properties of starch in binary system,starch+protein/starch+tea polyphenols,and ternary system,starch+protein+tea polyphenol.The adsorption characteristics of tea polyphenols was valued in different systems.The research results have important theoretical guiding significance for the development of low-glycemic index foods.The main findings are as follows:Different particle sizes medium-gluten wheat flour was added in 0%,5% and 10%(w/w)gluten to prepared for Chinese noodles.The noodles were gound and separated in large and small size.The objectives of the study were to understand the content of gluten and granules size(flour size/ noodle size)effect on the noodles structure,physicochemical and the digestion rate and extent of starch.The results showed that the more gluten samples had,the smoother the particle surface was,and the larger the area of the gluten network.The water solution index was higher with flour particle size decreasing,the faster the rate of interaction with the enzyme,due to the small particles granules having larger specific surface area than the large one.The digestibility slowed down with the flour size being smaller and the content of gluten increasing.However,the size of noodle granules had no significant effect on the digestive rate.Binary and ternary blends were prepared using wheat starch mixed with gluten or/ and EGCG/EGC.The changes of starch digestion rate and digestion degree in different systems and the mechanism were explored.Studies have found that gluten protein had an adsorption effect on ?-amylase,which could slow the digestion rate of starch,but had no significant influence on the final degree of starch digestion.The addition of tea polyphenols had a significant effect on the digestibility of starch,especially epigallocatechin gallate(EGCG)that interacted with starch and ?-amylase,which reduced the rate by 15.8%-30.4%.In ternary blends,because of the interaction between gluten and tea polyphenols,tea polyphenols slowing down the digestion rate of starch was inhibited.