Effect of storage periods and packaging materials on the proximate and chemical properties of frozen blue whiting (Micromesistius poutassou) at different exposure time

Abstract

This research seeks to determine the effect of storage periods and packaging materials on the proximate and chemical properties of frozen blue whiting (Micromesistius poutassou) at different exposure time – 0 hour, 2 hours and 4 hours, on arrival at the laboratory. Frozen M. poutassou were bought and stored in a commercial cold room for 12 weeks at -10oC and packed in different packaging materials (Ziploc bag, foil paper and carton) with un-wrapped samples for analysis which lasted 90 days and was conducted every 14 days to measure the moisture, protein, fat, ash, fibre and nitrogen free extract (NFA) content of the fish sample as well as iodine value, peroxide value, saponification value, acid value, free fatty acid and hydroxyl value of fish oil. The result clearly reveals that during storage, the different packaging materials showed significantly (p<0.05) decreasing trend in protein, lipid, ash, fibre and NFA content with increasing storage period and time of analysis except for the moisture content that showed opposite trend. For the chemical properties, the saponification value, peroxide value, free fatty acid, acid value and hydroxyl value showed significantly (p<0.05) increasing trend in the different packaging materials with increasing storage period and time of analysis. While the iodine value decreased with increasing period of storage and time of analysis; the iodine, saponification, peroxide and hydroxyl values were not within the acceptable limits.