干热处理对油菜籽蛋白功能特性的影响

Effects of dry heating treatment on the functional properties of rapeseed protein

实验研究了菜籽蛋白在热处理过程中的功能特性的变化，为菜籽粕的科学加工提供理论依据。实验首先采用差示扫描量热法（DSC）获得菜籽蛋白中两种主要成分12S球蛋白和2S清蛋白的变性温度分别为81℃和60℃。然后通过80℃和100℃对菜籽蛋白进行不同时间（15、30、60、90、120min）的千热处理，分别测定了菜籽蛋白热处理过程中吸油性、乳化性、溶解性及消化率的变化情况。结果发现：随着热处理时间的延长，菜籽蛋白的吸油性在加热60min时降到最低，然后又升高；80℃热处理15-60min，100℃热处理15-30min，乳化性均比对照组高，但随后都迅速降低。蛋白溶解性均随着时间的延长呈下降趋势，100℃热处理90、120min蛋白极度变性，随着pH值的变化溶解度几乎不再变化。80℃热处理15。60min能明显提高蛋白的消化率，而100℃热处理组则使得蛋白的消化率普遍下降。实验结果表明，通过适度的加热能够改善菜籽蛋白的吸油性、乳化性及消化率，但对溶解性却没有明显的改善作用。

Abstract： The object of this research is to study the change of functional properties of rapeseed protein during heat treatment process, to provide theoretical basis for the scientific process of rapeseed meal. The experiment firstly studied the denaturation temperature of 12S globulin and 2S albumin in rapeseed protein by differential scanning calorimetry （DSC）.The denaturation tem- perature was 81 ℃ and 60 ℃ respectively. Then rapeseed proteins were treated by dry heating within different time（ 15, 30, 60, 90, 120 min）.The oil absorbency, emulsibility, protein solubili- ty and protein digestibility of rapeseed protein were determined. The study show that：the oil ab- sorbency decreased to the minimum at 60 min and then increased within heating time. After heated 15-60 rain by 80 ℃ or 15-30 rain by 100 ℃, the emulsibility was higher than the con- trol group, but it decreased quickly with the time gonging on. The protein solubility showed a decreasing trend. After heating 90 rain and 120 rain, The protein solubility almost did not changed with the pH. After heated 15-60 rain by 80 ℃, the protein digestibility obviously im- proved, however the protein digestibility of groups heated by 100 ℃ were generally lower than the control group＇s. The results show that moderate heating treatment can improve the oil absor- bency, emulsibility and protein digestibility of rapeseed protein, but have no obvious improve- ment on protein solubility.