马铃薯淀粉废水蛋白的功能特性

以碱提酸沉法制备的马铃薯淀粉废水蛋白为原料,分别考察了pH值、NaCl浓度和温度对蛋白功能特性(溶解性、持水能力、乳化性及乳化稳定性、起泡性及泡沫稳定性)的影响。结果表明,pH值、NaCl浓度和温度对蛋白的功能特性产生不同程度的影响。在等电点(pH 4.0)时,马铃薯蛋白表现出最低的溶解性、持水性、乳化性、乳化稳定性及起泡性,而泡沫稳定性最好。在较低NaCl浓度(0.2 mol/L)时,蛋白溶解性、持水能力、乳化性和乳化稳定性随NaCl浓度的增加而提高,而高浓度的NaCl(0.2 mol/L)对上述性质具有抑制作用;蛋白的起泡性和泡沫稳定性在NaCl浓度为0.4 mol/L时具有最大值。在4~80℃范围内,蛋白质的各项功能性质随温度的升高均呈现先增加后降低的趋势,且溶解性、持水性、乳化稳定性、起泡性及泡沫稳定性在40℃时最佳,乳化性在60℃最佳。

Functional Properties of Protein Extracted from Potato Starch Wastewater

The effects of pH, NaCl concentration and temperature on functional properties (solubility, water-holding
capacity (WHC), emulsifying activity (EA), emulsifying stability (ES), foaming capacity (FC) and foam stability (FS)) of
protein extracted by alkali from potato starch wastewater and precipitated by acid were investigated. The results showed
that functional properties of potato protein were affected by pH, NaCl concentration and temperature to different extents.
Solubility, WHC, EA, ES and FC were the lowest at its isoelectric point (pH 4.0), while FS exhibited the best properties.
Solubility, WHC, EA and ES were improved by increasing NaCl concentration (0–0.2 mol/L), but inhibited by higher NaCl
concentration (> 0.2 mol/L). On the other hand, FC and FS reached their maximum values at NaCl concentration of 0.4 mol/L.
As temperature increased from 4 to 80 ℃, all functional properties increased at first and decreased later. Potato protein
exhibited the highest solubility, WHC, ES, FC and FS at 40 ℃ and best EA at 60 ℃.