Atlantic salmon (Salmo salar, L.) as raw material for the smoking industry. I: effect of different salting methods on the oxidation of lipids

The changes in total fat content, fatty acid composition, tocopherol, ascor bic acid, pH and oxidation were analysed in response to different salting m ethods, either dry or brine, in cold-smoked (20 or 30 degreesC) Atlantic sa lmon (Salmo salar, L.). The fish were lean ocean-ranched salmon caught at I celand in June 1998 and farmed Norwegian salmon slaughtered in November 199 8 and April 1999, differing in fresh fillet fat content from 84 to 169 g kg (-1) wet weight. The total fat content decreased in all groups during proce ssing, whereas the relative fatty acid composition of the fillets was not s everely affected during salting and cold-smoking. The most conspicuous proc ess consumption of antioxidants in all the groups was the relative ascorbic acid loss (58-82%). Generally, no clear effect of different salting method s was observed on the tocopherol loss during processing, but brine salting had a stronger effect on both fat and ascorbic acid loss than dry salting. The fattiest fish showed the highest oxidation during processing and they l ost more tocopherol, but the final oxidation levels were generally low (thi obarbituric acid reactive substances, TBARS: 6.0-14.7 mu mol kg(-1)), refle cting the antioxidative protection offered by the vitamins during processin g. (C) 2001 Elsevier Science Ltd. All rights reserved.