Bulgarian Marine and Freshwater Fishes as a Source of Fat-Soluble Vitamins for a Healthy Human Diet

The aim of the present study evaluates the fat-soluble vitamins all-trans retinol (vitamin A), cholecalciferol (vitamin D₃) and α-tocopherol (vitamin E) content in the fresh edible tissue of Bulgarian fish species: marine-grey mullet (Mugil cephalus) and bonito (Sarda sarda), and freshwater-rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio). The sample preparation procedure includes alkaline saponification, followed by liquid-liquid extraction with n-hexane. All-trans retinol, cholecalciferol and α-tocopherol were analyzed simultaneously using RP-HPLC\UV\FL system with analytical column C18 ODS2 Hypersil™. The fat soluble vitamins content (μg per 100 g wet weight) in the fresh edible fish tissue of analyzed fishes are in the ranges: vitamin A from 2.7 ± 0.4 to 37.5 ± 3.4 μg/100 g ww; vitamin D₃ from 1.1 ± 0.1 to 11.4 ± 0.6 μg/100 g ww; vitamin E from 121.4 ± 9.6 to 1274.2 ± 44.1 μg/100 g ww. Three fat-soluble vitamins occur in higher amounts in rainbow trout and grey mullet species. According to recommended daily intake (RDI), they are a good source of cholecalciferol.