Effect Of Gallic Acid On Physicochemical And Digestive Properties Of Rice

In this paper,study the influences and effects of japonica rice and glutinous rice on physicochemical properties and in vitro digestion characteristics treated with different concentrations gallic acid(GA)(0%,1%,3%,5%).Through comparison and analysis on different characteristics of rheological qualities,thermodynamic properties,microstructure and multi-dimensional structure,it is contributed to preliminary study on the effects of physicochemical properties of japonica rice and glutinous rice on in vitro digestion characteristics.At the same time,the effects of gallic acid with different concentrations on the digestion and rheological properties of glutinous rice and glutinous rice were studied under autoclaving condition(121℃,30 min).The main findings are as follows:(1)The effects and influences on the digestion and physicochemical properties of japonica rice treated with of gallic acid.Compared with the control group,the digestibility of japonica rice treated with different concentrations’(1%,3%,5%)GA decreased by 10.34%,19.61%,and 23.59%,respectively,which can speculate that enzyme activity was inhibited by gallic acid and the change of starch structure were caused.The gallic acid treatment significantly reduced the peak viscosity,bottom viscosity and the final viscosity of japonica rice starch,which demonstrated that the complexation between gallic acid and starch affects the hydration of japonica rice starch,and the inhibition of the rebound indicates that the interaction between them affects the structure of the starch molecule;the rheological properties indicates that the japonica rice starch paste remains non-Newtonian fluids with pseudoplasticity after treatment,gallic acid increases the shear recovery of japonica rice starch and is positively correlated with the concentration;the thermodynamic correlation index decreases to varying degrees,which is related to the increase of the spatial structure of gallic acid into the starch molecule.The multi-scale structural analysis by scanning electron microscopy,Fourier infrared spectroscopy and X-ray diffraction showed that GA had little effect on the microstructure,crystal form and relative crystallinity of japonica rice starch,but increased its short-range order.(2)The effect on the digestion and physicochemical properties of glutinous rice treated with gallic acid.Compared with the control group,the digestibility of glutinous rice decreased by 2.44%,5.59%and 9.36%,respectively,indicating that the effect of gallic acid on the digestion characteristics of glutinous rice starch was related to the molecular structure of starch;the peak viscosity of glutinous rice starch after gallic acid immersion was higher than the control group.The blank group indicated that gallic acid treatment improved the hydration of glutinous rice starch,which proved that the ratio of linear to amylopectin affected the interaction between starch and GA;the consistency coefficient of rheological properties increased first and then decreased.In terms of multi-size structure:GA has little effect on the microstructure and crystal form of glutinous rice starch,but the relative crystallinity decreases remarkably with the increase of GA concentration,and the short-range ordered structure increases without significant japonica rice.(3)The effect on the digestion and rheological properties of japonica rice and glutinous rice treated with gallic acid-autoclaving.The japonica rice and glutinous rice were subjected to gallic acid-pressure heat treatment,and the rheological properties showed that the proper amount of gallic acid combined with autoclaving improved the structural stability of japonica rice and glutinous rice,indicating that the effect of gallic acid on rice was related to not only the concentration of gallic acid,but also pressure heat treatment process.By studying the effects on the digestion and physicochemical properties of japonica rice and glutinous rice treated with gallic acid in different concentrations.It is preliminarily concluded that the enhancement of starch anti-digestion characteristics in rice is mainly affected by the change of starch physicochemical properties after gallic acid treatment.The effect of gallic acid-pressure heat treatment on rice digestion and rheology was studied,and the pressure heat treatment increased the interaction between starch and acid,which caused the effect on starch to be more significant.It provides a reference for the effect study on starch qualities treated with phenolic acids.