Amino acid, vitamin and mineral profiles of smoked fish as affected by smoking methods and fish types

Abstract

This study was carried out to evaluate the amino acid, vitamin and mineral profile of smoked fish as affected by smoking methods and fish types. Forty samples of five types of fresh fish (Guinean barracuda, Spotted tilapia, Bonga shad, Nigerian tongue sole and Silver catfish) were purposively collected from 20 processing centres in Lagos State. The samples were divided into two batches, with each batch smoked using traditional drum and modern kiln methods. The contents of the smoked fish products (amino acids, vitamins and minerals) were determined. Results showed that the amino acid concentrations in g/100 g crude protein (cp) of lysine, arginine and leucine were in the ranged 7.47–7.83, 6.27–6.54 and 7.32–7.68, respectively, for drum-smoked fish, while those of the non-essential amino acids, glutamic acid, aspartic acid, and glycine were in the range 14.19– 14.52, 9.62–9.81 and 7.01–7.42, respectively. Similar results were obtained from kiln-smoked fish samples although with slightly higher values than in drum-smoked fish samples. In conclusion, it was found from this study that smoking method has no significant effect on the amino acid composition of smoked fish samples, but fish types had. Moreover, smoking method had a significant effect on vitamin contents; this might be due to the temperature of smoking as some of the vitamins investigated are heat labile. Thus, the high amino acid contents in smoked fish could supplement the corresponding deficiency in plant protein diets, especially in developing countries. Therefore, the proteins in a mixed diet could be utilized optimally for a healthy body constitution, especially among children and other vulnerable groups.