Glycation from α-dicarbonyl compounds has different effects on the heat-induced aggregation of bovine serum albumin and β-casein

摘要

alpha-Dicarbonyl compounds are generated in large amounts during heat treatment in food production. This work compared the influence of glycation by alpha-dicarbonyl on the hydrothermal aggregation of bovine serum albumin (BSA) and of beta-casein (beta-CN). Glycation by alpha-dicarbonyl compounds was found to be more efficient than glycation by glucose in reducing the free amino groups, surface hydrophobicity and isoelectric point of BSA, thus greatly inhibited the hydrothermal aggregation of BSA. In addition, glycation by alpha-dicarbonyl greatly transformed the rigid BSA aggregates into flexible structures, based on analysis by fluorescence spectrum, transmission electron microscope and small-angle X-ray scattering. In contrast, both the aggregation process and aggregates conformation of beta-CN were found to be minimally affected by glycation, possibly due to the intrinsic disorder of beta-CN. This work highlights the substantial influences of alpha-dicarbonyl on dietary proteins during heat treatment depending on the protein structural characteristics.

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