Changes of physicochemical properties of rice glutelin fibril aggregates during storage

Abstract

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） at 85 ℃ 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 ℃ for 4 days, the emulsifying properties were significantly improved. The surface hydrophobicity of RGFAs solution formed by heat treatment for 2~10 h decreased 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.

Keywords

• protein fibril aggregates
• particle size
• viscosity
• starch gelatinization
• inhibition