The Effect of Lemon Juice on Shelf Life of Sous Vide Packaged Whiting (Merlangius merlangus euxinus, Nordmann, 1840)

Abstract

Sous vide technology provides ready-to-eat seafoods having an extended shelf life. The aim of this study was to evaluate the effect of lemon juice, citric acid, on the quality of sous vide whiting (Merlangius merlangus euxinus, Nordmann, 1840). Whiting fish were salted (0.2%) and divided into two groups. First group was vacuum packaged, pasteurized, and stored at 4 +/- 1 A degrees C (SV). The second group was treated with lemon juice for 30 min, then packaged, pasteurized, and stored similarly (LSV). The shelf life of SV samples was considered as 35 days since their mesophilic (6.79 +/- 0.07 log cfu/g) and psychrophilic (7.28 +/- 0.04 log cfu/g) aerobic bacteria counts and TBARS values (9.04 +/- 0.03 mg MDA/kg) were above the limits at that day, and samples were not accepted by the panelists in sensory test (3.9 +/- 0.2). LSV samples rejected on the 56th day (2.9 +/- 1.3), however, gave better sensory scores than SV samples. On the 42nd day of storage, the contents of TVB-N (32.46 +/- 8.69 mg/100 g) and TMA-N (14.24 +/- 4.17 mg/100 g) of LSV samples exceeded the limits, but the mesophilic (6.23 +/- 0.10 log cfu/g) and psychrophilic (6.01 +/- 0.11 log cfu/g) aerobic bacteria counts were acceptable until the 56th and 63rd days, respectively. Treating sous vide packaged whiting with lemon juice reduced bacterial load and extended shelf life and acceptability by at least 7 days compared with untreated samples.