Effects of frozen storage on the proximate composition and formaldehyde content in some selected fish from three different sources of southern Bangladesh

Abstract

The study was conducted in aims to investigate the effects of frozen storage and cooking conditionson proximate compositions and formaldehyde content (FA) in some selected fish from three different sourcesin Bangladesh. Proximate composition in fresh and final frozen samples was determined by standard AOACmethod and FA content in fresh, frozen stored, and cooked samples was determined by spectrophotometricmethod. Among the studied fishes, marine fish contained higher protein (except Rita), lipid, and ash followedby estuarine and culture fish samples. Protein, moisture and ash content decreased and lipid content increasedsignificantly (p<0.05) during frozen storage for all samples and sources. The FA was lower in cultured fishsamples compared to that of the river and marine fish samples, both at fresh and end of frozen storage. Atfresh condition, FA content in all samples ranged from 0.41 to 0.71µg/g, 0.51 to 0.89µg/g, and 0.73 to1.69µg/g which increased to 0.95 to 2.11µg/g, 1.74 to 1.95µg/g, and 3.22 to 5.20µg/g at end of the storageperiod, respectively (p<0.05). Further, FA content significantly decreased after cooking in all the fishsamples (p<0.05). However, irrespective of fish species and sources, the FA content was higher than WHOrecommended value (0.2 µg/g). The study findings revealed that longer frozen storage of fish could be apublic health concern to the consumers.