Northwest A&F University, College of Mechanical and Electronic Engineering, Yangling, Shaanxi 712100, China.
Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi 712100, China.
Food Chem. 2019 Aug 15;289:537-544. doi: 10.1016/j.foodchem.2019.03.072. Epub 2019 Mar 16.
To investigate the influence of radio frequency (RF) stabilization treatment on rice bran protein isolate (RBPI) properties, functional, structural and thermal behaviors of RBPI obtained from RF treated RB were evaluated under various temperatures between 80 and 120 °C holding for 5 min. The results showed that RF heating had negative impact on the yield, purity, foaming properties and solubility of RBPI when the treatment temperature was higher than 100 °C, while the absorption and emulsifying properties were improved. No significant changes were observed in primary structure of RF treated samples, but the second structure changed with an increase in random coil and a decrease in β-sheet, α-helix and β-turn. The decreased tryptophan fluorescence and increased surface hydrophobicity suggested alterations in tertiary structure. RF treatment also caused noticeable decrease in denaturation temperature and enthalpy of RBPI. The results would provide basic information for food applications of proteins isolated from RF stabilized RB.
为了研究射频（RF）稳定处理对米糠蛋白分离物（RBPI）性质的影响，评估了在 80 至 120°C 之间不同温度下，经过 RF 处理的米糠得到的 RBPI 的功能、结构和热行为，保持 5 分钟。结果表明，当处理温度高于 100°C 时，RF 加热对 RBPI 的产率、纯度、起泡性能和溶解度有负面影响，而吸收和乳化性能则得到改善。RF 处理样品的一级结构没有明显变化，但二级结构发生变化，无规卷曲增加，β-折叠、α-螺旋和β-转角减少。色氨酸荧光的减弱和表面疏水性的增加表明三级结构发生了变化。RF 处理还导致 RBPI 的变性温度和焓明显下降。该结果将为 RF 稳定米糠中分离得到的蛋白质在食品中的应用提供基础信息。
