Microbiological and Physicochemical Quality of Salted Bluespot Mullet (Valamugil seheli) Stored at Different Temperature

Abstract

Changes in the microbiological and physicochemical quality of salted wild mullet (Valamugil seheli) stored at ambient temperature (22 ± 1°C) and refrigerator (4 ± 1°C) for 180 days were investigated. The total mesophilic viable counts in salted fish stored at ambient temperature and at refrigerator ranged from 2.04 ± 0.08 to 4.15 ± 0.06 log cfu/g−1 and from 3.62 ± 0.39 to 4.52 ± 0.50 log cfu/g−1, respectively. Populations of psychrotrophic viable bacteria in salted fish stored at ambient temperature and at refrigerator ranged from 2.51 ± 0.13 to 4.08 ± 0.04 log cfu/g−1, and from 3.43 ± 0.34 to 4.49 ± 0.52 log cfu/g−1, respectively. The total mesophilic and psychrotrophic viable counts in salted fish stored at ambient temperature and at refrigerator were significantly decreased (P < 0.05) gradually throughout the storage period. Moreover, none of the salted mullet samples harbored coliform including Escherichia coli.The salt, pH, water activity (Aw) moisture, protein, lipid and ash values of salted fish stored at ambient temperature ranged from 20.3 to 23.2%, 5.6 to 6.2, 0.283 to 0.755, 10.3 to 44.5, 23.1 to 56.1, 4.5 to 17.0 and 19.0 to 23.9, respectively, whereas the corresponding values of salted fish stored at refrigerator ranged from 18.0 to 23.2%, 5.1 to 6.5, 0.730 to 0.755, 33.0 to 44.5, 23.1 to 40.1, 4.5 to 5.8 and 19.0 to 21.9, respectively.The total volatile basic nitrogen value of salted fish stored at ambient temperature and at refrigerator ranged from 34.5 to 57.4 and 34.5 to 51.8 mg/100 g, respectively.The histamine value of salted fish stored at ambient temperature and at refrigerator ranged from 16.0 to 18.0 and from 16.0 to 18.6 mg/100 g, respectively. Practical Applications: Salting is one of the oldest and most common methods that have been used worldwide for fish preservation. This study aimed to determine the microbiological and physicochemical quality of salted bluespot mullet (Valamugil seheli) during refrigerated storage (4 ± 1°C) and at ambient temperature (22 ± 1°C). The results obtained from this study demonstrated that the salted mullet had high levels of total volatile basic nitrogen and histamine. Therefore, the results of this study would be useful for the scientific community and can be utilized by researches in future studies as well as by manufacturers to develop better processing and preservation strategy for salted fish.