Effect of esterification on the absorption of astaxanthin in rainbow trout, Oncorhynchus mykiss (Walbaum) |
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| Authors: | D A White G I Page J Swaile A J Moody & S J Davies |
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| Institution: | Department of Biological Sciences, University of Plymouth, Plymouth, Devon, UK |
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| Abstract: | Gastrointestinal and serum absorption of astaxanthin was studied in rainbow trout, Oncorhynchus mykiss (Walbaum) (217 ± 2 g) fed diets supplemented with either esterified astaxanthin (from Haematococcus pluvialis) or free astaxanthin (synthetic, as 8% w/w beadlets) at similar levels (50 mg kg?1). After 56 days of feeding, there was a significant difference (P = 0.0582) between steady‐state serum astaxanthin concentrations for fish fed free (2.0 ± 0.3 μg mL?1) or esterified astaxanthin (1.3 ± 0.1 μg mL?1) at the 90% confidence level. However, following ingestion of a single meal supplemented with free or esterified astaxanthin, the rates of astaxanthin absorption into serum were not significantly different (P > 0.1) (0.8 ± 0.2 µg mL?1 h?1 and 1.0 ± 0.4 µg mL?1 h?1 respectively). In fish fed both free or esterified astaxanthin, higher absorption (P < 0.05) of astaxanthin by the ileal (0.8 ± 0.14 μg g?1 and 0.9 ± 0.15 μg g?1 respectively) compared with the posterior (0.2 ± 0.01 μg g?1 and 0.3 ± 0.14 μg g?1 respectively) intestine was recorded. This confirmed the role of the anterior intestine in carotenoid absorption. Non‐detectable levels of esters in digesta taken from the hind intestine suggest the anterior intestine is also the primary region for ester hydrolysis. |
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| Keywords: | astaxanthin esters intestine absorption |
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