Effect Of Rice Protein On Starch Retrogradation And Its Application Research

Rice serves as the basic food staple for over 50%of the world’s population,and ricebased products are widely available in the market.However,these products possess high levels of starch and moisture content,leading to food quality degradation during storage,sales,and circulation,which ultimately results in economic losses and resource wastage.This study focuses on examining the dose-response relationship and impact of rice protein on the gelatinization and retrogradation properties of rice starch.The Osborne method is employed to separate and extract major protein components of rice protein,and then high antiretrogradation protein components are introduced to investigate their mechanism of action on starch retrogradation.By comparing two distinct protein components,we aim to explore the effects of different proportions on the retrogradation properties of rice gel.The study will provide a theoretical basis and technical reference for the regeneration control of rice products.Firstly,a mixture of rice protein and rice starch was created by combining them in varying ratios(0%-16%).This was done to explore the impact of increased levels of rice protein on the retrogradation properties of rice starch.The results demonstrated that higher levels of rice protein work to decrease the enthalpy of rice starch retrogradation,gel hardness,crystallinity,semi-crystalline layered structure thickness,and starch gel fragmentation.Additionally,the mobility of water molecules is improved,and the retrogradation of starch is significantly inhibited with a nonlinear concentration effect.It is worth noting that when the protein content of rice increased from 0%to 12%,the inhibition effect of retrogradation was directly proportional to the quantity of rice protein.However,once the protein content surpassed 16%,the capacity of the proteins to bind together into aggregates weakened the probability of forming interactions with the starch molecules.Therefore,its ability to inhibit the recrystallization of starch molecular chains diminished.Secondly,the traditional Osborne approach was utilized to isolate and purify rice protein,resulting in four distinct protein fractions as glutelin,globulin,albumin,prolamin.To investigate potential mechanisms,the two protein components,glutelin and globulin,exhibited a significant ability to mitigate the enthalpy of starch retrogradation.These findings indicate that both protein components exhibited notable suppressive effects on the regeneration of rice starch,with suppression efficacy gradually increasing from 0%to 12%.Results from retrogradation enthalpy,crystallinity,short-range order,and semi-crystalline analyses demonstrate that glutelin wielded a stronger anti-retrogradation impact compared to globulin.Glutelin’s relatively low solubility is attributed to steric hindrance and interaction with starch molecules to limit regeneration which can be seen from scanning electron microscope and confocal laser scanning microscopy.In contrast,globulin demonstrated greater solubility and water retention capacity than glutelin,effectively binding with water molecules to decrease the required availability of water for starch chain recrystallization,ultimately influencing the retrogradation process of starch.Finally,glutelin and globulin components were blended in varying proportions and combined with rice starch at a ratio of 12:88 to create rice gel samples.An investigation on effect of the protein components in the rice gels was conducted.The findings revealed that as the globulin component concentration increased,the moisture content of the rice gels increased.Additionally,a gradual decrease in hardness,viscosity and chewiness was observed.Upon examination of data relating to enthalpy of retrogradation,crystallinity,short-range order,and semi-crystalline sheet thickness,it was evident that those incorporating compound protein components exhibited a reduced rate of retrogradation.Of these samples,the lowest degree of retrogradation was observed in the sample containing only the glutelin component.Upon further increase of the globulin component,a weakened anti-retrogradation effect was observed.