Color Stability of Rainbow Trout Fillets during Frozen Storage

The effects of frozen storage (3 and 6 months at −20 and −80°C) on stability of carotenoids and color [CIE, (1976) L*a*b* and H(°) ab ] in vacuum‐packed fillets of rainbow trout were studied in a paired‐sample experiment. The trout were fed diets containing astaxanthin or canthaxanthin at different water salinities and temperatures. Carotenoids in the flesh were stable (up to 5% loss) for 6 months at −20 or −80°C, regardless of carotenoid sources and rearing conditions. Frozen storage resulted in increased L* (lightness), a* (redness) and b* (yellowness), and decreased H(°) ab (hue) values. Color characteristics from different parts of the fillet differed significantly.