摘要
超声辅助冷冻是一项崭新的食品冷冻技术.为了理解超声环境下冷冻改善食品品质的机制,作者通过红外光谱对冷冻的面筋蛋白-重水体系中蛋白的二级结构变化进行了研,结果表明典型的蛋白酰胺Ⅰ带和Ⅱ带分别出现在1 640 cm-1(C=O伸缩)和1 550 cm-1(N-H弯曲/C-N伸缩) ;采用曲线拟合的方法研究了不同实验条件下蛋白酰胺Ⅰ带二级结构的变化,结果显示,与传统的实验条件相比面筋蛋白-重水体系经超声辅助冷冻和冷藏后其二级结构没有明显变化,而传统条件下冷冻后的面筋蛋白-重水体系冷藏后其二级结构发生了明显变化:α-螺旋的含量减少、无规卷曲的含量增加.研究结果显示超声辅助冷冻的效果是面筋蛋白网络中形成了小而均匀的冰晶,从而减少了对面筋蛋白网络的破坏.
The ultrasound-assisted freezing processing is a novel technique for food freezing. To understand the better quality mechanism of the food during the ultrasound-assisted food freezing, the changes in protein secondary structure in frozen gluten-heavy water system are studied by Fourier transform infrared spectroscopy （FTIR）, and the effect of ultrasound-assisted freezing on gluten-heavy water system has been studied. The typical protein absorption bands of amide Ⅰ and amide Ⅱ appear at the region （1 640 cm^-1） （C=O stretching） and the region （1 550 cm^-1） （N-H bending/C-N stretching） respectively, while the curve fitting is also used to investigate conformational changes in the secondary structure of protein absorption bands of amide Ⅰ under varying experimental conditions. Compared with the conventional freezing process, protein secondary structure does not change ultimately during the ultrasound-assisted freezing process and the frozen storage period after the gluten-heavy water sample column is frozen by ultrasound-assisted freezing; the frozen storage period after the gluten-heavy water sample column is frozen by conventional freezing results in a decrease of the amount of α-helixes accompanied by an increase of the content of the extended β-sheet conformations. This paper suggests that the ultrasonic effects result in the small ice crystal formation which lowers the deformation and deterioration of gluten network.
出处
《陕西科技大学学报（自然科学版）》
2008年第3期132-137,共6页
Journal of Shaanxi University of Science & Technology
基金
国家自然科学基金(20436020,20506006)
关键词
超声辅助冷冻
红外光谱
面筋蛋白-重水体系
冷冻储藏
ultrasound-assisted freezing
and deterioration of gluten network. FTIR
gluten-heavy water system frozen storage
