Increasing the quality of cold-stored Atlantic Salmon (Salmo salar Linnaeus, 1758) via single and combined use of natural preservatives: chitosan, nisin and garlic essential oil

It was aimed to reduce the economic and commercial damages caused by the loss of quality during marketing of salmon, a commercially popular fish around the world. Considering the trend of the consumer towards natural preservatives, the effects of low molecular weight chitosan (Ch, 2%), nisin (N, 0.5%), garlic essential oil (G, 1: 100 v:w) and their combinations (ChN, ChG, NG and ChNG) on the quality of cold-stored (2 +/- 1 degrees C) salmon were investigated. The treatments containing chitosan gave successful results. When combined with nisin and garlic oil; chitosan was very effective to retard microbiological and physicochemical spoilage during storage. Chitosan-added samples also resulted in better sensory scores. The ChN samples had the lowest microbiological counts and pH, TVB-N and TMA-N values of this group remained below the acceptability limit during storage. Unlike other quality parameters, TBAR(S) values were found to increase more rapidly in chitosan-treated groups during storage period, but none of these groups reached the limit of acceptability during the study. The results indicated that chitosan significantly increases the shelf life and microbial quality of salmon, especially when combined with nisin. Increasing quality by using natural preservatives is important in terms of reducing economic losses, as well as delivering perishable foods such as salmon to consumers in remote areas and sustaining limited resources.