Non‐gelatinized starch influences the deposition of n‐3 fatty acids in the muscle of a tropical freshwater fish, Labeo rohita

Abstract

A 60-day feeding trial was conducted to study the influence of gelatinized (G) to non-gelatinized (NG) starch ratio in the diet on fatty acids profiles and oxidative status in Labeo rohita fingerlings. Two hundred and thirty-four fingerlings (average weight: 2.53 g) were distributed in six treatment groups with each of three replicates. Six semi-purified diets either containing NG and/or G corn starch (42.43%) viz., T(1) (100% NG and 0% G starch), T(2) (80% NG and 20% G starch), T(3) (60% NG and 40% G starch), T(4) (40% NG and 60% G starch), T(5) (20% NG and 80% G starch) and T(6) (0% NG and 100% G starch) was fed to respective groups. Catalase, superoxide dismutase and malic enzyme activities decreased linearly with the increasing level of G starch, whereas reverse trend was found for glucose-6-phosphate dehydrogenase. Total saturated fatty acids in muscle increased with the increasing level of G starch in the diet. Total n-3 fatty acids decreased linearly with the increasing level of G starch in the diet. Among the n-3 fatty acids, linolenic acids content was more in NG starch fed group. Similarly, eicosapentaenoic acid contents gradually decreased with increasing level of G starch content. The n-6/n-3 ratio was higher in G starch fed group. This suggests that dietary starch type may be manipulated for quality improvement of fish flesh.