FROZEN STORAGE QUALITY OF RAINBOW-TROUT (ONCORHYNCHUS-MYKISS) AS AFFECTED BY OXYGEN, ILLUMINATION, AND FILLET PIGMENT

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