Effects of dietary astaxanthin concentration and feeding period on the skin pigmentation of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)
Data(s) |
01/12/2008
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Resumo |
A single-factor experiment was conducted to investigate the effects of dietary astaxanthin concentration on the skin colour of snapper. Snapper (mean weight=129 g) were held in white cages and fed one of seven dietary levels of unesterified astaxanthin (0, 13, 26, 39, 52, 65 or 78 mg astaxanthin kg<sup>−1</sup>) for 63 days. Treatments comprised four replicate cages, each containing five fish. The skin colour of all fish was quantified using the CIE L<sup>*</sup>, a<sup>*</sup>, b<sup>*</sup> colour scale after 21, 42 and 63 days. In addition, total carotenoid concentrations of the skin of two fish cage−1 were determined after 63 days. Supplementing diets with astaxanthin strongly affected redness (a<sup>*)</sup> and yellowness (b<sup>*</sup>) values of the skin at all sampling times. After 21 days, the a<sup>*</sup> values increased linearly as the dietary astaxanthin concentration was increased before a plateau was attained between 39 and 78 mg kg<sup>−1</sup>. The b<sup>* </sup>values similarly increased above basal levels in all astaxanthin diets. By 42 days, a<sup>*</sup> and b<sup>*</sup> values increased in magnitude while a plateau remained between 39 and 78 mg kg<sup>−1</sup>. After 63 days, there were no further increases in measured colour values, suggesting that maximum pigmentation was imparted in the skin of snapper fed diets >39 mg kg<sup>−1</sup> after 42 days. Similarly, there were no differences in total carotenoid concentrations of the skin of snapper fed diets >39 mg kg<sup>−1</sup> after 63 days. The plateaus that occurred in a<sup>*</sup> and b<sup>* </sup>values, while still increasing in magnitude between 21 and 42 days, indicate that the rate of astaxanthin deposition in snapper is limited and astaxanthin in diets containing >39 mg astaxanthin kg<sup>−1</sup> is not efficiently utilized. Astaxanthin retention after 63 days was greatest from the 13 mg kg<sup>−1</sup> diet; however, skin pigmentation was not adequate. An astaxanthin concentration of 39 mg kg<sup>−1</sup> provided the second greatest retention in the skin while obtaining maximum pigmentation. To efficiently maximize skin pigmentation, snapper growers should commence feeding diets containing a minimum of 39 mg unesterified astaxanthin kg<sup>−1</sup> at least 42 days before sale.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Wiley-Blackwell Publishing Ltd |
Relação |
http://dro.deakin.edu.au/eserv/DU:30022576/Jones-effectsofdietary-2009.pdf http://dx.doi.org/10.1111/j.1365-2109.2008.02063.x |
Direitos |
2009, Wiley |
Palavras-Chave | #astaxanthin #dose response #Pagrus auratus #skin colour #snapper |
Tipo |
Journal Article |