Frozen Storage Quality of Rainbow Trout (Oncorhynchus mykiss) as Affected by Oxygen, Illumination, and Fillet Pigment

Abstract

We investigated the influence of packaging materials with high, medium and low oxygen transmission rates (OTR) on the development of 2-thiobarbituric acid-reactive substances (TBARS) and astaxanthin retention in rainbow trout fillets. Three different levels of astaxanthin, during dark or illuminated frozen storage were studied. Samples were analyzed after 17,29 and 36 wk frozen storage. Rancidity developed more rapidly in packages with high OTR. This effect was more pronounced in illuminated samples, also verified by sensory evaluation. Fillets with highest astaxanthin content reached maximum TBARS after 29 wk. The two less pigmented sample groups reached maximum after 17 wk frozen storage, indicating antioxidative effects of astaxanthin.

Flesh quality of raw and smoked fillets of Atlantic salmon as influenced by dietary oil sources and frozen storage

“…Nevertheless, on smoked fillets, a slight decrease of astaxanthin was observed after freezing. The reduction of carotenoid content during frozen storage was already reported for rainbow trout (Ingemansson, Pettersson, & Kaufmann, 1993;Jensen et al, 1998) and salmon (Bjerkeng & Johnsen, 1995;Scaife, Onibi, Murray, Fletcher, & Houlihan, 2000) while No & Storebakken (1991) found stable concentration of astaxanthin and canthaxanthin during frozen storage. This contradiction could be explained by the difference of storage time, temperature and also the concentration of carotenoids included in the diets.…”

“…In recent years, farmed salmonid production has increased substantially and to regulate the market supply, fish may be frozen (Sheehan, OÕConnor, Sheehy, Buckley, & FitzGerald, 1998). Frozen storage influences colour stability of Atlantic salmon and rainbow trout (Bjerkeng & Johnsen, 1995;Jensen, Birk, Jokumsen, Skibsted, & Bertelsen, 1998;No & Storebakken, 1991), decreases liquid holding capacity and also influences the texture of the fillets (Mørkøre, Hansen, Unander, & Einen, 2002;Solberg, Hegli, & Solberg, 2000). However, to our knowledge, no study has been performed on the effects of frozen storage on quality of salmon grown with the utilisation of vegetable oils as the principle lipid in the diets.…”

Effect of light on colour stability of sliced smoked rainbow trout Oncorhynchus mykiss fed astaxanthin

“…Astaxanthin was determined in homogenized muscle and not in the surface layer. After 15 days of chilled storage, the level of astaxanthin was little affected by either light or storage conditions in accordance with Bjerkeng and Johnsen (1995). But this is in contradiction with the work reported by Christophersen, Bertelsen, Andersen, Knuthsen, and Skibsted (1992).…”

Singlet versus Triplet Reactivity in Photodegradation of C40 Carotenoids

“…In relation to food systems, it seems to be important to realize (i) that the scavenging of lipid radicals most effectively results in chain breaking under conditions of low oxygen pressure (Burton and Ingold, 1984;Jørgensen and Skibsted, 1993) and (ii) that oxygenated carotenoids such as astaxanthin and canthaxanthin are more effective free-radical scavengers than -carotene (Terao, 1989;Miki, 1991). In agreement herewith, more recent stability studies of sensitive foods like liquid eggs and salmon fillets seem to confirm that oxygenated carotenoids yield protection against oxidation during processing and especially during subsequent storage where oxygen may be depleted in the product (Lai and Gray, 1995;Clark et al, 1995;Bjerkend and Johnsen, 1995). Future use of carotenoids as additives to animal feed in order to increase the carotenoid level in foods of animal origin or as added antioxidants to processed foods will, however, clearly benefit from a deeper insight into the mechanisms by which carotenoids are interferring with lipid oxidation in foods.…”