Effect of carotenoids from red pepper and marigold flower on pigmentation, sensory properties and fatty acid composition of rainbow trout

Effects of dietary supplementation with krill meal on pigmentation and quality of flesh of rainbow trout (Oncorhynchus mykiss)

“…The protein content was nearly equal to that reported for rainbow trout at market size, whereas the lipid content appeared lower than data reported both by Yanar et al (2007) and by Chaiyapechara et al (2003); the latter ascertained a proportion of 8.8% of lipids in the trout fed on a commercial diet based on a 17% lipid content.…”

“…The fatty acid profile showed a very high proportion of EPA and DHA, and a low rate of linoleic acid with a favourable n-3/n-6 PUFA ratio. These results appeared more satisfactory than those reported by Yanar et al (2007) who, using a basal diet containing 45% crude protein, 10% crude fat, supplemented with commercial astaxanthin and natural pigmenting compounds, obtained EPA levels ranging from 5.73% (red pepper) to 5.95% (commercial astaxanthin). Studies carried out in rainbow trout reared in freshwater and seawater cages (Haliloĝlu et al, 2004) also reported lower EPA contents and PUFA than those obtained in our experiment.…”

“…However, the SalmoFan method proved unsuitable when farmed and wild salmon were compared, as observed by Johnston et al (2006) who did not In relation to carotenoid pigments and astaxanthin content, although in our experiment fish receiving natural pigments exhibited a paler muscle colour than those fed a diet containing synthetic astaxanthin, the amounts of carotenoids and astaxanthin contained in the diet were considered to be adequate for the pigmentation of the rainbow trout. In other studies (Yanar et al, 2007), carried out using natural pigment compounds such as red pepper and marigold flower, the carotenoid contents found in the fish fillet ranged from 1.5 to 5.6 mg/kg depending on the application time, but synthetic astaxanthin provided the highest carotenoid accumulation in the fish followed by red pepper. In the rainbow trout, canthaxanthin was more efficiently absorbed (3.8-7.9 mg/kg) in the flesh than the paprika carotenoids (2.4-3.1 mg/kg) (Akhtar et al, 1999).…”

“…Other papers reported that muscle colour attributes were more affected by the astaxanthin source than by the oil source; this was reported by Choubert et al (2006) who ascertained that trout fed on synthetic astaxanthine showed higher chroma (C*), redness and yellowness than fish fed on feed supplemented with astaxanthin from the green micro-algae Haematococcus pluvialis. Using other natural pigmenting compounds, such as red pepper, in comparison with commercial astaxanthin, Yanar et al (2007) observed that the fillet colour was lighter. Similar results were obtained by Akhtar et al (1999), who observed that paprika, compared with canthaxanthine, produced less pigmentation of the muscle with higher values in lightness and redness.…”

“…In this situation, studies on natural sources of astaxanthin able to favour flesh pigmentation for an alternative pigmentation of salmonids have increased. Pigments such as shrimp waste (Diler and Gökoglu, 2004), red yeast Phaffia rhodozyma (Gentles and Haard, 1990;Bjerkeng et al, 2007), green algae Haematococcus pluvialis (Choubert and Heinrich, 1993) and red pepper and marigold flower (Yanar et al, 2007) have been tested with different results. The use of krill, including around 85 species of pelagic crustaceans belonging to the order Euphausiacea, in feeds to colour different salmon species has also been investigated (Storebakken 1988;Scott et al, 1994), in addition to considering the possibility of using krill meal to replace fish meal (Moren et al, 2006;Yoshitomi et al, 2007).…”