Effects of acidification and sterilisation on the quality of channel catfish (Ietalurus punctatus) fillets

Summary This study aims to investigate the effects of acidification and sterilisation on the quality of channel catfish, based on the texture, colour, physical and chemical properties, protein composition and water migration of channel catfish fillets. The results showed that the hardness, chewiness and colour of acidified and sterilised (AS) groups were significantly better than unacidified and sterilised (NAS) groups. The content of TCA soluble peptide in NAS was significantly higher than AS groups, indicating that high‐temperature sterilisation induced more protein degradation. Electrophoresis analysis also showed that the protein bands in the unacidified and sterilised (NAS) groups weakened or disappeared. There was no significant difference in the fat oxidation index of peroxide value and thiobarbituric acid value indicating that little effect on oxidation was induced by acidification and sterilisation. After sterilisation, the water transferred from immobilised water to free water, and the weight loss rate of acidified non‐sterilised (ANS) groups was significantly higher than AS. On the whole, acidified channel catfish could be sterilised at a lower temperature, thus having better texture, colour and lower weight loss rate. The sterilisation temperature of 91–95 °C was recommended to maintain a better quality of ready‐to‐eat acidified fish fillets.