Emulsifying properties and antioxidant activity of soy protein isolate conjugated with tea polyphenol extracts
Emulsifying properties and antioxidant activity of soy protein isolate conjugated with tea polyphenol extracts
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DOI：
10.1007/s13197-020-04391-9
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发表时间：
2020-04-24
影响因子：
3.1
通讯作者：
Suhartono, Maggy Thenawidjaja
中科院分区：
文献类型：
--
作者：
Djuardi, Anwika Utami Putri;Yuliana, Nancy Dewi;Suhartono, Maggy Thenawidjaja
通过将蛋白质与酚类物质偶联，可以改善蛋白质的功能性质，如乳化、泡沫形成和抗氧化活性。本文报道了大豆分离蛋白(SPI)与绿茶和红茶提取物中的酚类物质偶联后，其结构、理化和功能性质的变化。SPI与茶叶提取物的偶联是在碱性处理(pH 9.0)后暴露于空气中进行的。结果表明，SPI偶联增加了蛋白质的分子尺寸，降低了蛋白质的疏水性。红茶提取物的疏水性降低效果大于绿茶提取物。茶多酚结合物显著提高了大豆分离蛋白的乳化能力(P&t；0.05)，乳化稳定性提高了59%。用0.75%(w/w)的绿茶多酚提取物制备的SPI-茶多酚结合物具有较强的液滴间排斥力、较小的乳液液滴尺寸和较低的液滴尺寸分布多分散性指数，具有最佳的乳化性能。虽然偶联产物的乳状液稳定性仍不如卵磷脂，但SPI的抗氧化活性显著提高(p<；0.05)，且呈浓度依赖关系。SPI-红茶多酚结合物比SPI-绿茶多酚结合物具有更强的抗氧化活性。本研究显示了SPI-茶多酚结合物用作食品乳化剂的可行性和益处。
Functional properties of proteins, such as emulsification, foam formation and antioxidant activity, can be improved by conjugating the proteins with phenolic substances. We reported here changes in the structural, physicochemical and functional properties of Soy Protein Isolate (SPI) after conjugation with phenolic substances in the green tea and black tea extracts. Conjugation of SPI with tea extracts were conducted using alkaline treatment (pH 9.0) followed by air exposure. The results showed that conjugation of SPI increased the protein molecular size and decreased the protein hydrophobicity. The hydrophobic decreasing effect by the treatment was larger with the black tea extract than by green tea extract. SPI-tea polyphenol conjugates significantly (p < 0.05) increased the emulsifying ability of SPI up to 43% and the emulsifying stability of SPI up to 59%. SPI-tea polyphenol conjugates which was prepared using 0.75% (w/w SPI) green tea polyphenol extract showed the best emulsifying properties with strong repulsion forces between the droplets, smaller emulsion droplet size and lower polydispersity index of droplets size distribution. Although the conjugation product is still inferior to egg lecithin in emulsion stability, antioxidant activity of SPI was significantly (p < 0.05) improved in a concentration dependant manner. SPI-black tea polyphenol conjugates showed greater antioxidant activity than SPI-green tea polyphenol conjugate. The present study shows the feasibility and benefits of the use of SPI-tea polyphenol conjugates as a food emulsifier.