乙酰化改性对米渣蛋白功能性质的影响

Effect of acetylated modification on the functional properties of rice residue proteins

摘要: 采用乙酰化对米渣蛋白进行改性,研究了米渣蛋白在乙酰化改性过程中巯基和二硫键含量、表面疏水性、溶解性以及乳化性的变化。结果表明,随改性程度的增加,米渣蛋白中暴露巯基含量逐渐增加,总游离巯基含量逐渐下降,二硫键含量逐渐增加,表面疏水性先下降后升高。乙酰化改性后的米渣蛋白在p H5~10范围内的溶解性、乳化活性和乳化稳定性明显增加,但是p H2~4范围内的溶解性和乳化活性却有所降低。可见,乙酰化改性能改善米渣蛋白的部分功能性质。

Abstract: Acetylation was applied to modify rice residue proteins. Sulfhydryl( SH) and disulfide bond( SS)contents,surface hydrophobicity(H0),protein solubility(PS) and emulsifying activities were evaluated. With increasing of the extent of acetylation,exposed SH content was increased,total free SH content was decreased,SS content was increased,H0 was decreased first,and then increased. PS emulsifying activity index(EAI) and emulsion stability index(ESI) of rice residue proteins were improved at p H5¹0 by acetylation,but PS and EAI was decreased at p H2⁴. The data suggested that some functional properties of rice residue proteins could be improved by acetylation.