Potential of microalgae as source of health-beneficial bioactive components in produced eggs

In line with the growing interest in humans' nutrition, production of microalgae-based functional foods characterized by an increased content of bioactive substances is attractive. The aim of this study was to investigate the potential of microalgae as additives to feed for laying hens, to enrich the eggs with polyunsaturated fatty acids (PUFA) and selenium/carotenoid antioxidants. Our results showed that supplementation of hens by feed containing 1% of Trachydiscus minutus or 1% of Japonochytrium marinum leads to increase of long-chain PUFA in eggs by 26-66%. Addition of 1% of Scenedesmus obliquus to feed causes the increase of lutein and cantaxanthin in eggs by 48% and 18%, respectively, and addition of 0.5% selenium enriched Chlorella vulgaris increases the final content of organic selenium in eggs by 100-152%. As concerns selenium, it is important to notice that its bioavailability has to be considered. Despite the higher concentration of total selenium in Vischeria helvetica than in C. vulgaris, its bioaccessibility in Vischeria was limited, thus out of usage for feeding purposes. Administration of combinations of selenium enriched Chlorella  +  Japonochytrium and Chlorella  +  Schizochitrium verified the increased concentrations of organic selenium, PUFA, as well as carotenoids, with no adverse effect on quality and productivity of eggs. The study confirmed the potential of both traditional as well as new microalgae to be used as feed supplements for functional eggs production. The supplementation of hens by specific microalgae combinations could be advantageous in terms of spectrum of bioactive compounds present.