Impact of ice structuring protein on myofibrillar protein aggregation behaviour and structural property of quick-frozen patty during frozen storage.

The goal of this study was to explore the cryoprotective effect of ice structuring protein (ISP) on the aggregation behaviour and structural changes of myofibrillar protein (MP) from quick-frozen pork patties during frozen storage. Frozen storage causes the formation of large protein aggregates and weakens MP structures. After adding ISP into patties, MP had a more stable aggregation system, which was manifested by a uniform particle size distribution and significantly higher absolute zeta potential (11.71 mV) than the control (9.56 mV) (P < 0.05). Atomic force microscopy results showed that the surface roughness of MP aggregation decreased by 9.78% with ISP after freezing for 180 d. Additionally, compared to patties without ISP, the MP carbonyl content from the ISP-treated patty decreased by 32%, and the free amino content increased by 14.99% during frozen storage. Results from circular dichroism spectroscopy and fluorescence spectroscopy showed that MP secondary and tertiary structure stability in patties improved with ISP. Overall, ISP has the potential to improve MP aggregation and structural stability during frozen storage.