Analysis of structural changes and anti-inflammatory capacity in soybean protein isolates conjugated with anthocyanins

Abstract

This study investigated the covalent cross-link at alkaline (pH 9.0) between different concentrations of anthocyanins and soybean protein isolate (SPI). The structure of the product was analyzed by SDS-PAGE, fluorescence spectrum, and circular dichroism. In order to test the effects of SPI on the anti-inflammatory ability of anthocyanins, in vitro inflammatory cell model was set by RAW264.7 cell line. Results showed that fluorescence quenching of soybean protein isolates was static strengthened. The α-helix content of the secondary structure gradually decreased with the content of the β-sheet and random coil increasing. A super molecular weight subunit was observed, and the complex of soybean protein and anthocyanins can markedly reduce the secretion of TNF-α and NO at the dose of 200 μg/mL when the concentration of anthocyanins is greater than 0.167 mg/mL.

Keywords:
anthocyanins; soybean protein isolate; conjugates; inflammatory