School of Food and Biological Engineering, Hefei University of Technology, Hefei, China.
Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, China.
J Sci Food Agric. 2021 Sep;101(12):4959-4968. doi: 10.1002/jsfa.11139. Epub 2021 Mar 1.
Protein can be used as an emulsifier to improve emulsion stability at the interface of water-in-oil emulsion. However, natural soybean protein isolate (SPI) does not meet the high demands as an emulsifier in the food industry. The effect of acylation modification by ethylenediaminetetraacetic dianhydride (EDTAD; 0-300 g kg ) on the physicochemical properties of SPI was studied.
The results of the Fourier transform infrared spectra analyses showed that carboxyl groups were introduced into the SPI structure by the EDTAD treatment. The carboxyl concentration of SPI was increased by 30-74.07% with an increase in EDTAD addition from 50 to 300 g kg . When 150 g kg EDTAD was added, the surface hydrophobicity, the emulsifying activity, and the absolute value of the zeta potential were increased by 213%, 120%, and 68% respectively, and the particle size decreased to 247 nm. The droplet size of emulsion decreased to 10 μm when pH was 6. At the same concentration of SPI and pH, the absolute value of zeta potential of the emulsion was biggest. A comparison of the emulsions during storage showed the improvement of emulsion stability was related to the increase in the zeta potential and the decrease in the average particle size. The experimental group showed no destabilization on day 21, and no obvious aggregation phenomenon was observed.
Acylation modification by EDTAD changed the emulsifying properties of SPI and enhanced the stability of the SPI emulsion. © 2021 Society of Chemical Industry.
蛋白质可用作乳化剂，以改善水包油乳液界面处的乳液稳定性。然而，天然大豆分离蛋白（SPI）作为食品工业中的乳化剂，其性能并不能满足高要求。本文研究了乙二胺四乙酸二酐（EDTAD；0-300 g kg）酰化改性对 SPI 理化性质的影响。
傅里叶变换红外光谱分析结果表明，SPI 结构中通过 EDTAD 处理引入了羧基。随着 EDTAD 添加量从 50 增加到 300 g kg，SPI 的羧基浓度增加了 30-74.07%。当添加 150 g kg EDTAD 时，表面疏水性、乳化活性和zeta 电位绝对值分别增加了 213%、120%和 68%，粒径减小至 247 nm。乳液的粒径在 pH 值为 6 时降至 10 μm。在相同 SPI 浓度和 pH 值下，乳液的 zeta 电位绝对值最大。对储存期间乳液的比较表明，乳液稳定性的提高与 zeta 电位的增加和平均粒径的减小有关。实验组在第 21 天没有失稳，也没有观察到明显的聚集现象。
EDTAD 的酰化改性改变了 SPI 的乳化性能，提高了 SPI 乳液的稳定性。 © 2021 化学工业协会。
