Quality changes of European catfish (Silurus glanis) from warm‐water aquaculture during storage on ice

Abstract
Summary: Gutted European catfish (Silurus glanis) from warm‐water aquaculture was stored in ice for 30 days. The limit of saleability was reached after approximately 20 days, and cooked fillets became inedible after about 27 days. Quality changes were investigated using established analytical methods; pH, total volatile bases (TVB), thiobarbituric acid number and texture measurements by Instron were not usefully predictive of shelf‐life or possible storage time. The Fish Tester and Torrymeter values decreased from 848 to 376 and 111 to 61, respectively. On day 27 the total aerobic bacterial counts had reached some 108/cm2 skin surface but only 105/g muscle. Hypoxanthine concentrations increased steadily to 17.2 mg/100 g, and ammonia levels increased from 11.5 to 18.7 mg/100 g muscle. There were no differences in the patterns obtained by isoelectric focusing of sarcoplasmic proteins from fresh and spoiled European catfish.