Nutritional value of fish soup from cultured brook trout (Salvelinus fontinalis, Mitchill, 1814)

Abstract

Introduction. The aim of this study is to estimate the nutritional value of fish soup from cultured brook trout in terms of a healthy diet for human consumption. Materials and methods. Fish soup was prepared from 23.65% previously cooked trout mince and 18.76% vegetables, and cooked for 35 mins. The final product was analyzed for the proximate composition, fatty acids and, mineral contents as well as carotenoids and vitamins B1, B2 and B6. Inductively coupled plasma Mass Spectrometer (ICPMS) was used for mineral content after decomposition of lyophilized samples. Fatty acids methyl esters were separated by gas chromatography by flame ionization detector (FID). High performance liquid chromatography (HPLC) was used for the estimation the contents of vitamins and carotenoids. Results and discussion. The proximate contents of soup were represented by 87.79% moisture, 8.18% protein, 2.89% crude fat, 1.17% dietary fibre, 0.62% ash and 0.03% carbohydrate. The energy value was calculated as 58.82 kcal/100g. The value of total polyunsaturated fatty acids (σPUFA) was higher than the values of total monounsaturated (σMUFA) and saturated fatty acids (σSFA) and accounted as 43.89, 34.93 and 19.83%, respectively. The main PUFA corresponded to linoleic acid as 27.14% followed by docosahexaenoic acid (DHA) as 7.92%. Total eicosapentaenoic acid+docosahexaenoic acid (σEPA+DHA) was observed as 9.21% which was accounted as 239.04 mg/100g soup. The results of this study demonstrated that a portion of trout soup (about 200g) would well cover daily recommended n-3 PUFA intake while slightly higher amount is required for daily EPA+DHA intake. Mineral contents were varied in the range of 1.77 31.52 mg/g (dwb), while the results obtained for vitamin B1, B2 and B6 and for carotenoids were comparable with the data given for different types of soups in literature. Conclusion. This study indicates that a nutritious fish soup can be produced from brook trout for human consumption suitable for a healthy diet.