Growth of psychrophilic microorganisms in chilled seafoods is important but they have limited use in shelf‐life studies because there is not an acceptability limit. In this study, pH, total volatile bases nitrogen (TVB‐N), trimethylamine nitrogen (TMA‐N), total mesophilic and psychrophilic aerobic bacteria analyses were used to estimate the shelf life of cold stored (+4 ± 1C) fish. Shelf life of horse mackerel was determined as 1 day, while cod and anchovy spoiled on the second day, and rainbow trout spoiled on the third day of storage. Total mesophilic aerobic bacteria counts did not indicate the spoilage remaining lower than the acceptability limit; but psychrophilic aerobic bacteria counts were around 6 log cfu/g, when the samples spoiled. It was determined that, estimation of the psychrophilic microorganisms gives better results to the shelf‐life estimation of chilled fish than mesophilic bacteria and 6 log cfu/g could be accepted as the acceptability limit. PRACTICAL APPLICATIONS Seafood is mostly stored and transported under chilled conditions. However, there is not a limit of acceptability for the psychrophilic microorganisms which are important to estimate spoilage of chilled foods. Thanks to this study, a limit of acceptability (6 log cfu/g) was determined for these microorganisms in cold storage conditions. This limit will be helpful in further studies to estimate the shelf life of chilled seafoods definitively.

Proximate compositions, amino acid compositions and fatty acid compositions of fish roe have been measured and compared. Glutamic acid, aspartic acid, lysine, and serine have been the major amino acids. However, Imperial-type caviar has also included higher amounts of tryptophan (p < 0.05). Essential /Nonessential (E/NE) ratio has been found to be between 0.93-1.23, and n3/n6 ratio has been found to be 2.56-8.06. Major fatty acids were C16:0, C18:1 n9c, C16:1 n7, C20:5n3, and C22:6 n3. Fish roes contain high amount of lipids and energy, however, they are also rich sources of unsaturated fatty acids, proteins and amino acids.

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This study examined the effect of lemon juice on sensory, biochemical and microbiological quality of sous vide (SV)-packaged bonito. Bonitos were salted (0.2%) and divided into two groups. The first group (SV) was vacuum-packaged in a gas barrier plastic pouch, pasteurised (70°C, 10 min) and stored at 4 ± 1°C. The second group [(lemon juice-treated sous vide (LSV)] was treated with lemon juice, vacuum-packaged, pasteurised and stored similarly. LSV samples had lower pH, mesophilic and psychrophilic aerobic counts than SV samples (P < 0.05), and they had better sensory quality. SV samples spoiled on the 35th day, while the LSV samples were acceptable until 49th day of storage. This result shows that treatment with lemon juice increased the acceptability and shelf life of SV packaged bonito for 2 weeks (40%). When compared to several other mild preservation procedures, addition of lemon juice to SV fish is inexpensive and uncomplicated method.