Effect of chitosan treatments on quality parameters of fresh refrigerated swordfish (Xiphias gladius) steaks stored in air and under vacuum conditions

Abstract

The present study examined the effect of chitosan (1.0% w/v) in combination with packaging on the shelf-life of fresh swordfish steaks. Treatments included the following: A (untreated, control samples stored in air), A-CH (treated with chitosan 1.0% w/v, stored in air), VP (untreated, stored under vacuum packaging) and VP-CH (treated with chitosan, stored under vacuum packaging). VP-CH significantly affected Total Viable Counts (TVC), Pseudomonas spp., H(2)S-producing bacteria (including Shewanella putrefaciens), lactic acid bacteria and Enterobacteriaceae. Production of TMA-N and TVB-N for A-CH, VP and VP-CH swordfish samples was significantly lower than for control (A) samples at day 8 of storage. Histamine formation for all treatments was low. A-CH and VP-CH resulted in significantly lower levels of putrescine, cadaverine and tyramine (day 8) as compared to A and VP swordfish samples. Results of this study indicate that the shelf-life of swordfish steaks can be extended using, either aerobic or vacuum packaging and in combination with chitosan, by approximately 4 (A-CH), 8 (VP) and 12 (VP-CH) days. Swordfish steaks treated with chitosan and stored under VP were sensorially acceptable up to 17days. The presence of chitosan (A-CH and VP-CH) did not negatively influence the taste of cooked swordfish.