Two microalgal species, Isochrysis galbana and Nannochloropsis oculata, were supplemented to the diet of laying hens, in either non-disrupted or disrupted (by high pressure homogenization) form, to examine the effect of the presence of a cell wall on the omega-3 long chain polyunsaturated fatty acid (n − 3 LC-PUFA) enrichment in the egg yolk. Only supplementation of Nannochloropsis led to significant differences in enrichment by supplementation of the two forms, with the highest enrichment obtained with the HPH-disrupted form. This confirms the presence of a rigid cell wall for this species, which reduces the bioaccessibility of the n − 3 PUFA. The needed conversion reaction from EPA to DHA on the other hand did not seem to effect the enrichment, since the same n − 3 LC-PUFA enrichment was obtained with the supplementation of the DHA source Isochrysis and the EPA source Nannochloropsis, the last in HPH-disrupted form.Next to the microalgal species, fish oil was also supplemented to the diet of the laying hens. Fish oil resulted in a higher enrichment in comparison with the microalgal species, either non-disrupted or HPH-disrupted. This might suggest a difference in bioaccessibility of the n − 3 PUFA when added as oil or biomass. |
