An investigation of rancidity inhibition during frozen storage of Wels catfish (Silurus glanis) fillets by previous ascorbic and citric acid treatment

Summary The effect of preliminary ascorbic and citric acid (AA and CA, respectively) soaking treatments on the rancidity development in Wels catfish (Silurus glanis) fillets during further frozen storage (−18 °C; up to 6 months) was studied. Rancidity development was measured by biochemical quality indices (formation of free fatty acids, peroxides and secondary oxidation products) and compared with sensory analysis (appearance, rancid odour and consistency) and general chemical analyses (pH, expressible moisture and heme iron contents). When compared with control samples, AA‐ and CA‐treated samples showed a lower (P < 0.05) formation of primary and secondary lipid oxidation compounds that was corroborated by a longer (P < 0.05) shelf‐life time as a result of a lower rancid odour formation. According to these results, control samples showed a higher (P < 0.05) heme iron breakdown (months 3–6) and a lower (P < 0.05) water‐holding capacity (higher expressible moisture value) (month 6).