Effects Of Germination On Physicochemical Properties Of Brown Glutinous Rice Flour And Its Starch

Due to the unique structural and digestive properties of glutinous brown rice,it has limited market value.At present,the research on rice mainly focuses on non-glutinous rice,and the research on germinated glutinous rice,especially the brown rice flour and its starch at different germination stages is less.So,this study use traditional germination process preparation of germinated 0,12,24,36,48,72 h glutinous brown rice,in order to reveal the effect of different germination time on the structure and physicochemical properties of glutinous brown rice flour and its starch,as well as to improve the structure and physicochemical properties of glutinous brown rice,on the basis of the guarantee its rich nutrition,aiming to provide the theoretical basis for the future development and the effective utilization of glutinous brown rice.The main research results are as follows:1.After 72 h of germination,the total starch content decreased from 84.27% to79.56%,the cellulose content increased from 1.15% to 3.63%,the total protein content increased from 10.45% to 12.49%,and the fat and ash content did not change significantly.2.After germination,the proportion of A chain in the starch of glutinous brown rice increased from 33.76% to 36.64%,The proportion of B1 chain gradually decreased from44.95% to 42.79%,while the total ratio of chain B2 and chain B3 decreased by 0.73%;More and larger holes appeared on the surface of starch granules;Starch granules at different germination stages had obvious polarization cross,and all of them were type A diffraction patterns.Before germinated 24 h,the hydrolysis of starch mainly occurred in the amorphous region,with no significant difference in relative crystallinity.However,when the germination time reached 36 h,relative crystallinity decreased by 0.4% compared with that before germination,and 1047 cm-1/1022 cm-1 decreased by 0.0073 compared with that before germination,and the structure of the crystalline region of starch was destroyed.3.With the extension of germination time,the gelatinization temperature of glutinous brown rice starch decreased by 3.92 °C after 72 h of germination.The enthalpy of gelatinization decreased from 12.72 J/g before germination to 11.95 J/g,the peak viscosity decreased from 1810 c P before germination to 1560 c P,the breakdown value increased by294 c P after germination,the final viscosity decreased by 620 c P after germination,and the setback value also decreased from 396 c P before germination to 320 c P.Glutinous brown rice starch paste germinated for 12 h had the weakest thermal stability and shear resistance,and the most difficult to retrogradation.Glutinous brown rice starch paste germinated for36 h was prone to retrogradation.4.About the glutinous brown rice flour,the gelatinization temperature decreased first and then rose;In this study,the maximum enthalpy of gelatinization of GB0 was 8.5988 J/g.After germination,the enthalpy of gelatinization of glutinous brown rice flour gradually decreased to 7.0036 J/g with the extension of germination time.Peak viscosity of glutinous brown rice flour had a sharp decline in 12 h after germination,by 814 c P to 230 c P,and with the extension of germination time gradually reduced to 30 c P,and breakdown and setback value also significantly lower,the thermal stability and shear resistance of the rice paste were significantly enhanced after the rice was germinated,while the gelatinicity was obviously weakened.Tend to be more elastic,germination of glutinous brown rice paste showed a typical dynamic rheological properties of weak gel,and the G ? and G " of glutinous brown rice paste with the increase of the germination time coming down.5.From this study,we can find that the gelatinization temperature of germinated glutinous brown rice flour generally higher than that of corresponding starches,the gelatinization enthalpy of germinated glutinous brown rice flour were significantly lower than the starches;RVA value showed that the peak viscosity(30~814 c P)of glutinous borwn rice flour was far lower than that of its corresponding starch(1560~1860 c P),and the effect of glutinous brown rice flour was more obvious than that of its starch.