Carboxymethyl cellulose-mediated crust restructuring regulates quality attributes and hazardous intermediate...

Fried battered oysters are widely appreciated for their crispy crust and tender interior. However, the intense heat-mass transfer that occurs during high-temperature frying can induce quality deterioration and promote the formation of hazardous intermediates. In this study, the effects of carboxymethyl cellulose (CMC) on batter properties, quality attributes, and hazardous intermediate accumulation were investigated. Rheological, Fourier transform infrared spectroscopy and microstructural analyses indicated that CMC restructured the batter network and promoted the formation of a gel barrier, thereby reducing moisture loss and oil uptake during frying and improving colour and texture attributes. Among the tested treatments, 0.5% CMC showed the greatest overall efficacy. The relatively intact gel network restricted oil transfer into the core oyster meat, thereby slowing lipid oxidation and oxidative damage to myofibrillar proteins, which was beneficial for maintaining the quality of the core meat. Meanwhile, this barrier effect attenuated the oxidative-Maillard coupled reaction environment and inhibited the accumulation of reactive α-dicarbonyl intermediates. Specifically, 0.5% CMC reduced 5-hydroxymethylfurfural in the fried crust by 33.42% and methylglyoxal in the crust and core meat by 35.04% and 47.53%, respectively. These findings suggest that CMC can be used as an effective batter improver to enhance the quality and reduce the accumulation of selected hazardous intermediates of fried battered oysters.