贮藏过程中米谷蛋白纤维聚集体理化性质变化规律

Changes of physicochemical properties of rice glutelin fibril aggregates during storage

目的:探究贮藏时间与不同加热时间下米谷蛋白纤维聚集体(Rice glutelin fibril aggregates,RGFAs)溶液功能特性之间的关系。方法:以米谷蛋白(Rice glutelin,RG)为原料,在85℃、pH 2.0的条件下加热2~15h制备得到RGFAs,在4℃下分别贮藏1d和4d,测定不同RGFAs样品的表面疏水性、乳化性、剪切黏度、RGFAs-淀粉混合物糊化特性及水解率。结果:在低温贮藏4d后,乳化性得到明显改善;热处理2~10h形成的RGFAs溶液的表面疏水性显著降低(P<0.05),而15h热处理后形成的RGFAs溶液表面疏水性无显著变化(P>0.05),同时15h-RGFAs溶液体系的剪切黏度降低。贮藏1d的2h-RGFAs与淀粉混合物的糊化温度最低(83.98±0.08)℃,且贮藏1d的RGFAs样品与小麦淀粉混合物的水解率更低。结论:贮藏1d的RGFAs样品对小麦淀粉的水解抑制作用优于贮藏4d的RGFAs样品。

Objective:To explore the relationship between functional properties of rice glutelin fibril aggregates(RGFAs)solution formed by different storage and heating time.Methods:The RGFAs samples were prepared by heating rice glutelin(RG)at85℃and pH 2.0 for 2~15 h,and stored at 4℃for 1 day and 4 days,respectively.The surface hydrophobicity,emulsifying property,shear viscosity of RGFAs samples as well as the gelatinization characteristics and hydrolysis rate of the mixture of RGFAs and starch were measured.Results:After storage at 4℃for4 days,the emulsifying properties were significantly improved.The surface hydrophobicity of RGFAs solution formed by heat treatment for 2~10 hdecreased significantly(P<0.05),while the surface hydrophobicity of RGFAs solution formed after 15 h of heat treatment did not change significantly(P>0.05),and the shear viscosity of 15 h-RGFAs solution decreased.The gelatinization temperature of the mixture of starch and 2 h-RGFAs stored for 1 day was the lowest(83.98±0.08)℃,and the hydrolysis rate of the mixture of starch and RGFAs samples stored for 1 day was lower than that of other samples.Conclusion:The inhibition of wheat starch hydrolysis by RGFAs samples stored for 1 day was better than that by RGFAs samples stored for 4 days.