热处理温度和离子强度对汉麻蛋白热聚集行为的影响

Effects of heat treatment temperature and ionic strength on thermal aggregation behavior of hemp protein

中文关键词:  汉麻蛋白  聚集体  离子强度  热处理

英文关键词:hemp protein  aggregation  ionic strength  heat treatment

中文摘要:

      目的 研究热处理和不同离子强度条件下汉麻蛋白的热聚集行为。方法 以汉麻籽为原料, 考察在80、90、100℃热处理下, 以及不同离子强度(0、0.2、0.4、0.6、0.8 mol/L NaCl溶液)下汉麻蛋白的ζ-电位、粒径、浊度、二级结构、凝胶电泳、巯基及二硫键等指标。结果 汉麻蛋白随着热处理温度的升高和离子强度的增大, ζ-电位绝对值降低、粒径增大、浊度增加; 电泳图中在70 kDa处有聚集条带显示; 傅里叶变换红外光谱显示随着热处理温度升高, α-螺旋结构显著降低, β-折叠和无规则卷曲结构显著增大; 随着离子强度增大, α-螺旋和β-转角结构显著降低, β-折叠结构增加, 无规则卷曲结构先增大后减小; 90℃热处理时游离巯基含量低于80℃和100℃, 二硫键含量在80℃处理下最少; 离子强度对汉麻蛋白总巯基影响不显著。结论 热处理温度的升高及离子强度增大对汉麻蛋白聚集行为具有促进作用, 为汉麻蛋白热加工工艺优化和品质调控提供了理论基础。

英文摘要:

      Objective To study the thermal aggregation behavior of hemp protein under heat treatment and different ionic strength. Methods Hemp seeds were used as materials, the ζ-potential, particle size, turbidity, secondary structure, gel electrophoresis, sulfhydryl and disulfide bond of hemp protein were investigated under heat treatment at 80, 90 and 100 ℃ and different ionic strength (0, 0.2, 0.4, 0.6 and 0.8 mol/L NaCl solution). Results The ζ-potential absolute value decreased, the particle size and the turbidity increased with the increase of heat treatment temperature and ionic strength of hemp protein. There were aggregation bands at 70 kDa in the electropherogram. FTIR showed that the α-helix structure decreased significantly, the β-sheet and random coil structure increased significantly with the increase of temperature. And the α-helix and β-turn structure decreased significantly, the β-sheet structure and the random coil increased first and then decreased with the increase of ionic strength. The content of free sulfhydryl group in 90℃ heat treatment was lower than 80℃ and 100℃. The disulfide bond content was the lowest at 80℃ heat treatment. The change of ionic strength had no significant effect on the sulfhydryl group of hemp protein. Conclusion The thermal aggregation behavior of hemp protein is promoted with the increase of heat treatment temperature and ionic strength, which provides a theoretical basis for the optimization of hot processing technology and quality control of hemp protein.