Changes in the quality indicators of extruded starter compound food for fish during storage

Abstract

The dynamics of changes in the quality indicators of the starting compound feeds produced by extrusion for zander, clary catfish and tilapia during their storage for 10 months has been studied. Warehousing was carried out in the spring-summer period, the air temperature in the warehouse ranged from +5 to +25 °C; relative humidity - from 60 to 75 %. Sampling for analysis was carried out during storage, after 2, 4 and 10 months of storage. It was found that, during storage, the content of crude protein and fat does not undergo significant changes, an increase in the acid and peroxide numbers of fat is observed in all samples, the acid number of fat increased to 29,5 mg KOH/g in the feed for zander, to 28,3 mg KOH/g in the feed for clary catfish, and in the feed for tilapia to 26,84 mg KOH/g. The peroxide number of fat increased from 0,1 % iodine to 0,22 % iodine in the feed for zander, from 0,1 % iodine to 0,19 % iodine in the feed for clary catfish and in the feed for tilapia 0,1 % iodine to 0,18 % iodine. It is noted that in pike perch feeds for 10 months of storage, the peroxide number reached 0,22 % iodine with an acceptable deviation in parallel determination of 0,05 %, the remaining indicators for feed safety were at the limit level in terms of the content of peroxide and acid numbers of fat, it follows that the feed should not be stored for more than 10 months.