Effect of coating time by sodium alginate edible film on quality and shelf life of frozen Kilka (Clupidaes delicatula)

This project was carried out in order to increase the shelf life of Kilka Fish and prevent color changes during cold storage. Edible film made of sodium alginate (1% concentration) was used for fish packaging. This project was carried out in four treatment and in triplicates. Treatments were coated samples at intervales times of 0, 2 and 4 hours shelf life in sodium alginate solution and uncoated Kilka (control samples). The coated and control samples were kept at -18 oC. Examination were carried out for a period of six months. Examination was conducted on 21 packs from each treatment on day 1 after processing and from first month untill sixth month after processing.Total bacterial counts and Staphylococcus bacteria count were lower in the coated samples compared to the control samples. Coliform, Escherichia coli and Pseudomonas bacteria contamination were not observed until the end of storage period in the coated samples. Moisture was less in the coated samples at time = 0 and was highest in the coated samples at time = 4 hour. Peroxide value, free fatty acids, thiobarbitoric acid, TVN and pH were higher in coated samples at time = 0 compared with other samples and in coated samples at time = 4 were lower compared with other samples. Statistically significant (p<0.05) decreases were observed in the coated and control samples during cold – storage. Sensory analysis carried out based on ranking method. Over all there was a significant difference (p<0.05) between the coated samples and control ones. The coated samples at time = 0 had the best quality. The coated samples at time= 4 hour had lower quality. According to the results, the coated samples had good quality until the end of storage period. Based on the results of sensory analysis the coated samples maintained quality for a period of three months.