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Astaxanthins

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Mark A Booth – 1st expert on this subject based on the ideXlab platform

  • Effects of dietary astaxanthin concentration and feeding period on the skin pigmentation of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)
    Aquaculture Research, 2008
    Co-Authors: Ben J. Doolan, Mark A Booth, Geoff L. Allan, Paul L. Jones

    Abstract:

    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(-1)) for 63 days. Treatments comprised four replicate cages, each containing five fish. The skin colour of all fish was quantified using the CIE L-*, a(*), b(*) 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(*)) and yellowness (b(*)) values of the skin at all sampling times. After 21 days, the a(*) values increased linearly as the dietary astaxanthin concentration was increased before a plateau was attained between 39 and 78 mg kg(-1). The b(*) values similarly increased above basal levels in all astaxanthin diets. By 42 days, a(*) and b(*) values increased in magnitude while a plateau remained between 39 and 78 mg kg(-1). 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(-1) after 42 days. Similarly, there were no differences in total carotenoid concentrations of the skin of snapper fed diets > 39 mg kg(-1) after 63 days. The plateaus that occurred in a(*) and b(*) 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(-1) is not efficiently utilized. Astaxanthin retention after 63 days was greatest from the 13 mg kg(-1) diet; however, skin pigmentation was not adequate. An astaxanthin concentration of 39 mg kg(-1) 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(-1) at least 42 days before sale

  • Effects of dietary astaxanthin source and light manipulation on the skin colour of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)
    Aquaculture Research, 2004
    Co-Authors: Mark A Booth, Rebecca J. Warner-smith, Geoff L. Allan, Brett D. Glencross

    Abstract:

    Two experiments were conducted with Australian snapper Pagrus auratus (Bloch and Schneider, 1801). The first was aimed at determining the dietary level of astaxanthin that improved skin redness (CIE a*values) of farm-reared snapper. Farmed snapper (ca. 600g) fed a commercial diet without carotenoids were moved to indoor tanks and fed the same diet supplemented with 0, 36 or 72mg astaxanthin kg-1 (unesterified form as Carophyll Pinktm) for nine weeks. Skin redness (CIE a* values) continued to decrease over time in fish fed the diet without astaxanthin. Snapper fed the diet containing 72mg astaxanthin kg-1 were significantly more red than fish fed the diet with 36mg astaxanthin kg-1 three weeks after feeding, but skin redness was similar in both groups of fish after 6 and 9 weeks. The second experiment was designed to investigate the interactive effects of dietary astaxanthin source (unesterified form as Carophyll Pinktm or esterified form as NatuRosetm; 60mg astaxanthin kg-1) and degree of shading (0%, 50% and 95% shading from incident radiation) on skin colour (CIE L*a*b*) and skin and fillet astaxanthin content of farmed snapper (ca. 800g) held in 1m3 floating cages. After 116 days, there were no significant interactions between dietary treatment and degree of shading for L*, a* or b*skin colour values or the concentration of astaxanthin in the skin. Negligible amounts of astaxanthin were recovered from fillet samples. The addition of shade covers significantly increased skin lightness (L*), possibly by reducing the effect of melanism in the skin, but there was no difference between the lightness of fish held under either 50% or 95% shade cover (P>0.05).

Brett D. Glencross – 2nd expert on this subject based on the ideXlab platform

  • Effects of dietary astaxanthin source and light manipulation on the skin colour of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)
    Aquaculture Research, 2004
    Co-Authors: Mark A Booth, Rebecca J. Warner-smith, Geoff L. Allan, Brett D. Glencross

    Abstract:

    Two experiments were conducted with Australian snapper Pagrus auratus (Bloch and Schneider, 1801). The first was aimed at determining the dietary level of astaxanthin that improved skin redness (CIE a*values) of farm-reared snapper. Farmed snapper (ca. 600g) fed a commercial diet without carotenoids were moved to indoor tanks and fed the same diet supplemented with 0, 36 or 72mg astaxanthin kg-1 (unesterified form as Carophyll Pinktm) for nine weeks. Skin redness (CIE a* values) continued to decrease over time in fish fed the diet without astaxanthin. Snapper fed the diet containing 72mg astaxanthin kg-1 were significantly more red than fish fed the diet with 36mg astaxanthin kg-1 three weeks after feeding, but skin redness was similar in both groups of fish after 6 and 9 weeks. The second experiment was designed to investigate the interactive effects of dietary astaxanthin source (unesterified form as Carophyll Pinktm or esterified form as NatuRosetm; 60mg astaxanthin kg-1) and degree of shading (0%, 50% and 95% shading from incident radiation) on skin colour (CIE L*a*b*) and skin and fillet astaxanthin content of farmed snapper (ca. 800g) held in 1m3 floating cages. After 116 days, there were no significant interactions between dietary treatment and degree of shading for L*, a* or b*skin colour values or the concentration of astaxanthin in the skin. Negligible amounts of astaxanthin were recovered from fillet samples. The addition of shade covers significantly increased skin lightness (L*), possibly by reducing the effect of melanism in the skin, but there was no difference between the lightness of fish held under either 50% or 95% shade cover (P>0.05).

Geoff L. Allan – 3rd expert on this subject based on the ideXlab platform

  • Effects of dietary astaxanthin concentration and feeding period on the skin pigmentation of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)
    Aquaculture Research, 2008
    Co-Authors: Ben J. Doolan, Mark A Booth, Geoff L. Allan, Paul L. Jones

    Abstract:

    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(-1)) for 63 days. Treatments comprised four replicate cages, each containing five fish. The skin colour of all fish was quantified using the CIE L-*, a(*), b(*) 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(*)) and yellowness (b(*)) values of the skin at all sampling times. After 21 days, the a(*) values increased linearly as the dietary astaxanthin concentration was increased before a plateau was attained between 39 and 78 mg kg(-1). The b(*) values similarly increased above basal levels in all astaxanthin diets. By 42 days, a(*) and b(*) values increased in magnitude while a plateau remained between 39 and 78 mg kg(-1). 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(-1) after 42 days. Similarly, there were no differences in total carotenoid concentrations of the skin of snapper fed diets > 39 mg kg(-1) after 63 days. The plateaus that occurred in a(*) and b(*) 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(-1) is not efficiently utilized. Astaxanthin retention after 63 days was greatest from the 13 mg kg(-1) diet; however, skin pigmentation was not adequate. An astaxanthin concentration of 39 mg kg(-1) 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(-1) at least 42 days before sale

  • Effects of dietary astaxanthin source and light manipulation on the skin colour of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)
    Aquaculture Research, 2004
    Co-Authors: Mark A Booth, Rebecca J. Warner-smith, Geoff L. Allan, Brett D. Glencross

    Abstract:

    Two experiments were conducted with Australian snapper Pagrus auratus (Bloch and Schneider, 1801). The first was aimed at determining the dietary level of astaxanthin that improved skin redness (CIE a*values) of farm-reared snapper. Farmed snapper (ca. 600g) fed a commercial diet without carotenoids were moved to indoor tanks and fed the same diet supplemented with 0, 36 or 72mg astaxanthin kg-1 (unesterified form as Carophyll Pinktm) for nine weeks. Skin redness (CIE a* values) continued to decrease over time in fish fed the diet without astaxanthin. Snapper fed the diet containing 72mg astaxanthin kg-1 were significantly more red than fish fed the diet with 36mg astaxanthin kg-1 three weeks after feeding, but skin redness was similar in both groups of fish after 6 and 9 weeks. The second experiment was designed to investigate the interactive effects of dietary astaxanthin source (unesterified form as Carophyll Pinktm or esterified form as NatuRosetm; 60mg astaxanthin kg-1) and degree of shading (0%, 50% and 95% shading from incident radiation) on skin colour (CIE L*a*b*) and skin and fillet astaxanthin content of farmed snapper (ca. 800g) held in 1m3 floating cages. After 116 days, there were no significant interactions between dietary treatment and degree of shading for L*, a* or b*skin colour values or the concentration of astaxanthin in the skin. Negligible amounts of astaxanthin were recovered from fillet samples. The addition of shade covers significantly increased skin lightness (L*), possibly by reducing the effect of melanism in the skin, but there was no difference between the lightness of fish held under either 50% or 95% shade cover (P>0.05).