effects of stock density on texture-colour quality and chemical composition of rainbow trout (oncorhynchus mykiss)

this study describes the effects of different stocking densities on texture/colour characteristics, protein content /amino acid and lipid content/fatty acid composition of rainbow trout fillet.stocking density was selected 5 (group a), 15 (group b), 25 (group c) kg fish m−3.tukey’s multiple comparison test showed insignificant differences between measured size/weight measurement and condition factors. no significant differences were found between a and c groups for colour analysis (l* and a* value) and texture profile analysis (hardness, adhesiveness, cohesiveness and gumminess values) of rainbow trout fillets.  the proximate composition analysis showed rainbow trout fillets from the a and c groups to exhibit higher values of moisture than the b group. fish from the a and b groups had a lower of ash and protein in comparison to c group samples. the highest fat values of rainbow trout were measured in b group samples. the content essential amino acid and non-essential amino acid was lower in a and b groups than in c groups. fish from the c group had higher content of polyunsaturated fatty acids, especially n-3, docosahexanoic acid (dha) and eicosapentaenoic acid (epa) in comparison to a and c group. as a result, 25 kg fish m−3 is recommended stock density in terms of product texture/color and composition quality.