Effect of staged thawing assisted antifreeze protein on quality of repeatedly freeze-thawed minced pork

Abstract

The effects of thawing at 4 °C, 25 °C, 25/-1 °C (staged thawing) on the quality of minced pork added with 0.2% antifreeze protein (AFP) and without AFP were respectively assessed by investigating the total thawing time, material loss, water distribution and Magnetic Resonance Imaging (MRI), color, microstructure, bacterial count, and lipid and protein oxidation of minced pork in the study. The results showed that the total thawing time of minced pork thawed at 25/-1 °C was significantly lower than that of thawed at 4 °C (P < 0.05). The material loss of the AFP sample thawed at 25/-1 °C was reduced. Meanwhile, the AFP samples thawed at 25/-1 °C appeared the shortest T22 relaxation time at the same F-T cycles, and inhibited the oxidation of lipid and protein, presenting the lowest malondialdehyde content and the highest the total sulfhydryl content, and restrained destruction of minced pork microstructure and slowed down the growth of microorganism during freeze-thaw cycles. Summarily, thawed at 25/-1 °C combined with 0.2% AFP addition emerged a tremendous potential to improve the quality of the repeatedly frozen-thawed pork.