Effect of lemon juice on the chemical and microbiological quality of rainbow trout (Oncorhynchus mykiss) under refrigerated storage

Abstract

In recent years, there has been an increasing interest in using food additives from natural sources to improve taste, texture and extend the shelf-life of foodstuffs. The aim of this study was to examine the quality changes in trout treated with lemon juice for 21 days. Fish were divided into T0, T1, T2 and T3 and treated with 0, 1%, 2% and 3% lemon juice respectively. The lowest pH was found in T3 followed by T2, T1 and T0. A significant difference in total volatile base nitrogen (TVBN), peroxide value (PV) and free fatty acid (FFA) was observed between the control and treatments, with the lowest increase in T3 followed by T2. Total plate count (TPC) crossed the limit in T2 and T3 on the 21st day, whereas in control and T1, the permissible limit crossed on the 12th and 18th days respectively. The sensory panel rejected the control on the 12th day and T1 and T3 on the 18th day; however, T2 remained acceptable till the 21st day, thus showing the promising effect of lemon juice on the quality of trout fillet and thereby increasing the shelf-life of the product by nine days.