The effect of microwave on the interaction of flavour compounds with G‐actin from grass carp (Catenopharyngodon idella)

BACKGROUND In order to investigate the influence of non‐thermal effects of microwaves on the flavour of fish and meat products, the G‐actin of grass carp in ice baths was exposed to different microwave powers (0, 100, 300 or 500 W); the surface hydrophobicity, sulfhydryl contents, secondary structures and adsorption capacity of G‐actin to ketones were determined. RESULTS As microwave power increased from 0 to 300 W, the surface hydrophobicity, total and reactive sulfhydryls increased; α‐helix, β‐sheet and random coil fractions turned into β‐turn fractions. As microwave power increased from 300 to 500 W, however, hydrophobicity and sulfhydryl contents decreased; β‐turn and random coil fractions turned into α‐helix and β‐sheet fractions. The tendencies of adsorbed capacity of ketones were similar to hydrophobicity and sulfhydryl contents. CONCLUSION The increased adsorbing of ketones could be attributed to the unfolding of secondary structures by revealing new binding sites, including thiol groups and hydrophobic binding sites. The decreased binding capacity was related to the refolding and aggregation of protein. The results suggested that microwave powers had obvious effects on the flavour retention and proteins structures in muscle foods. © 2017 Society of Chemical Industry