Storage of bonito (Sarda sarda, Bloch 1793) fish preped by gravlaks method at + 4±1 oc; physical, chemical and microbiological determination

The interest in seafood processed without heat treatment such as salting, marinating, cold smoking is increasing day by day. These products, also called lightly-processed seafood products, are preferred by consumers because they contain intense flavor and aroma. In this study, it was aimed to obtain a new product from bonito, which is often processed in brine or dry salted (lakerda) in Turkey, by the gravlax process applied to salmon in Scandinavian countries. After the fresh bonito was filleted, it was cured in a mixture of salt, sugar, black pepper, coriander and dill at +4oC for 72 hours. After the curing process, the bonito gravlaxes were packed in stretch (group A) and vacuum (group B) and stored at +4oC for 24 days and analyzes were carried out. Crude protein, crude oil, crude ash, moisture and carbohydrate content of fresh bonito used in the study, It was determined as 23.10, 19.54, 1.19, 55.77 and 0.39 g/100g, respectively. The salt and acid content of gravlax was 2.86% and 0.58. Crude protein and crude fat content of gravlax were found to be similar to fresh bonito (p>0.05). TVB-N content of fresh bonito is 20.66 mg/100g. Although there were fluctuations in TVB-N contents during storage in both groups, the maximum limit value was not exceeded on the 24th day. TBARs changes also fluctuated during storage and the highest was found as 3.50 mgMDA/kg. Total mesophilic aerobic bacteria, total psychrophilic aerobic bacteria, total yeast and mold, total coliform bacteria and S. aureus counts of bonito gravlax before packaging were 3.68, 3.08, 2.21, 2.17 and <0.30 Logkob/g, respectively. During the storage period, the total mesophilic anaerobic bacteria and E. coli counts of both groups were determined as <0.30 Logkob/g. Considering the "general acceptability" sensory score and "microbiological analysis" of the study, the shelf life of the groups; It can be given as the 15th day for the stretch-packed group A, and the 21st day for the vacuum-packed group B.