Effect of Traditional Canning on the Nutritional Composition and Amino Acid Profile of Bonito (Sarda sarda)

This study investigated the effects of the traditional bonito canning process on the nutritional and amino acid composition of the fish muscle. For this purpose, bonito pieces were soaked in a 5% brine solution for two days, then canned and subjected to heat treatment at 100°C for 30 minutes with the addition of sunflower oil, after which they were analysed. The crude protein, crude lipid, moisture, crude ash, and carbohdrate contents of raw bonito were 15.88, 15.25, 65.41, 1.98, and 1.48 g/100 g respectively. After salting, the crude protein and crude lipid contents decreased, whereas the crude ash content increased. The energy content of raw bonito is 206.74 kcal/100g whereas the energy content of canned bonito has been determined to be 231.50 kcal/100g. Among amino acids, glutamic acid, lysine, and aspartic acid were the most abundant in raw bonito. The predominant amino acids in salted bonito were similar to those in raw bonito (p>0.05). Comparing the amino acid compositions of raw and canned bonito, the levels of phenylalanine, leucine, isoleucine, methionine, valine, proline, tyrosine, alanine, serine, aspartic acid, arginine, lysine, cystine, and glutamic acid did not differ significantly (p>0.05). In this study, the ratio of total essential amino acids (EAA) to total non-essential amino acids (NEAA) in raw bonito was 0.82; this ratio decreased after salting (0.69) and subsequently increased to 0.80 after heat treatment. Consequently, the salting and heat treatment processes used in the traditional home-made production of canned bonito affect both the nutritional value and the amino acid composition of the fish.