Effects of preservation on chemical composition and sensory analysis of skipjack tuna (Katsuwonus pelamis) in Tema, Ghana

Abstract

Although fish is an integral part of Ghanaian diets and play important nutritional role, much research has not been conducted with respect to the nutritional composition and sensory analysis of marine fishes in Ghana. This study evaluated chemical composition and sensory analysis of Skipjack tuna (Katsuwonus pelamis) sampled from Tema in the Greater Accra region of Ghana. Four different samples; very dry smoked (Sample A), dry smoked (sample B), moist smoked (sample C) and fresh (sample D) skipjack tuna were used for this study. Chemical composition (moisture, ash and protein) was analysed using standard laboratory methods whilst sensory parameters (colour, odour, flavour, texture and overall acceptance) were assessed using 20 trained panelists. There were significant differences in moisture and crude protein contents (P < 0.05). Ash content was however non-significantly different. Moisture content for very dry smoked skipjack tuna, dry smoked skipjack tuna, moist smoked skipjack tuna and fresh skipjack tuna were 49.79 ± 1.73 %, 60.22 ± 1.80 %, 59.32 ± 0.01 % and 68.65 ± 0.16 %, respectively whilst crude protein content were 90.83 ± 1.09 %, 73.32 ± 1.09 %, 88.15 ± 1.19 % and 91.72 ± 0.19 %, respectively for very dry smoked skipjack tuna, dry smoked skipjack tuna, moist smoked skipjack tuna and fresh skipjack tuna. It can be concluded that different methods of preservation (smoking) have significant influence on proximate composition as well as sensory analysis. It is suggested that further studies be conducted on sensory analysis and proximate composition of fish sold on Ghanaian markets. In addition, we recommend that the Food and Drugs Authority (FDA) conduct regular studies on fish to ascertain the quality.