LAUSR

BACKGROUND Soybean meal, an abundant by-product of oil production industry, has a high content of protein. The compact globular structure of protein from soybean meal limits its wide application in food processing. Allicin has been found to have numerous functional properties. In this study, allicin was used to interact with soy protein isolate (SPI) and the functional properties of adducts were further investigated. RESULTS Binding of allicin significantly quenched the fluorescence intensity of SPI. Static quenching was the main quenching mechanism. The stability of adducts decreased with the increase of temperature. The greatest extent of binding between allicin and sulfhydryl groups (SH) of SPI was obtained at allicin/SH molar ratio of 1:2. The amino groups of SPI didn't bind to allicin covalently. SPI was modified by allicin through covalent and non-covalent interactions. Compared with SPI, the emulsifying activity index and foaming capacity of adducts with ratio 3:1 were improved by 39.91% and 64.29%, respectively. SPI-allicin adducts also exhibited obvious antibacterial effects. The minimum inhibitory concentrations (MICs) of SPI-allicin adducts on Escherichia coli and Staphylococcus aureus were 200 and 160 μg mL-1 , respectively. CONCLUSION The interaction of allicin with SPI is beneficial to perfect the functional properties of SPI. These adducts can be used in different food formulations as emulsifiers, foamers and transport carriers. This article is protected by copyright. All rights reserved.