喷雾干燥温度对生物解离浓缩蛋白粉微观结构的影响

研究大豆生物解离水解液,经喷雾干燥进口温度为140、150、160、170、180、190和200 ℃时,获得生物解离浓缩蛋白粉,进一步分析观察浓缩蛋白粉的粒径分布、微观形态、蛋白质二结构的含量以及微环境的变化。结果表明:经生物解离获得的浓缩蛋白粉,随着喷雾干燥进口温度的升高,平均粒径呈不断增大趋势,当进口温度为200 ℃时,平均粒径最大为3.94 μm;浓缩蛋白粉在扫描电镜下,呈球状、表层有凹陷及褶皱,且颗粒越大,其表面越光滑,喷雾干燥进口温度越高,颗粒越大;浓缩蛋白粉中蛋白质的二级结构以β-折叠结构和无规则卷曲为主,当进口温度为150 ℃时,β折叠含量最高,当进口温度为180 ℃时,无规则卷曲含量最高;荧光光谱分析喷雾干燥进口温度对浓缩蛋白粉的色氨酸周围空间结构无明显影响。

Effect of Spray Drying Temperature on Microstructure of Enzyme-assisted Aqueous Extraction Soybean Concentrated Protein Powder

The soybean biological dissociation hydrolysate was studied,and the biological dissociation concentrated protein powder was obtained at the spray-drying inlet temperature 140,150,160,170,180,190 and 200 ℃. Changes of particle size distribution,microscopic morphology,contents of protein secondary structure,and microenvironment of concentrated protein powder were analyzed. The results showed that the particle size and average particle size of the concentrated protein powder obtained by biological dissociation increased with the increasing of the spray drying inlet temperature. When the inlet temperature was 200 ℃,the average particle size was 3.94 μm at the maximum. Under the scanning electron microscope,the concentrated protein powder was spherical,the surface layer had dents and wrinkles,and the larger of the particle,the smoother of the surface. The higher the spray drying inlet temperature,the larger the particles were. The secondary structure of the protein in the concentrated protein powder mainly contained β-sheet structure and irregular curl. When the inlet temperature was 150 ℃,the β-fold content was the highest. And when the inlet temperature was 180 ℃,the irregular curl content was the highest. Fluorescence spectrum analysis showed that the temperature of spray-drying inlet had no significant effect on the spatial structure of tryptophan around concentrated protein powder.