Assessment of the bioactive and nutritional potential of novel food products enriched in Cystoseira abies-marina and Skeletonema sp. biomass

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaMicro and macroalgae are photosynthetic organisms of large abundance and diversity that contain a variety of compounds with high bioactivity and nutritional value. These compounds have been receiving an increasing interest of researchers due to their potentially positive effect on human health. This has also led to the development of applications for algal biomass, ranging from animal feed to cosmetics, pharmaceuticals, and functional foods. The use of algae biomass in the food industry is still a new concept with the potential to produce healthy foods with added nutritional and bioactive compounds. Although there are many countless studies that support the health benefits of algae, few studies quantify the bioavailability of those nutritional compounds. In vitro digestion methods currently being used for studying the bioaccessibility of said nutrients and bioactive compounds, allowing a better understanding of how those compounds can be used. In this work two algae species, microalgae Skeletonema sp. and macroalgae Cystoseira abies-marina, that are not thoroughly studied were analysed regarding their proximal composition, lipid composition, element composition, phenolic content and relevant bioactivities, as well as their bioaccessibility, in order to understand their potential to be incorporated in food products. Two food products enriched in algae, sauce and cookies, were prepared and analysed, displaying a higher content in polyphenols and higher antioxidant activity than the control in the bioaccessible fraction. The high arsenic concentration found in the macroalgae is also observed in food products prepared with this species requiring a speciation study to assess the risk to human health. The mixture of the food ingredients with Skeletonema sp. was beneficial for the bioaccessibility of monounsaturated fats in sauces, which increased with the incorporation of the microalgae. This work reinforced that incorporating algae in food products can be advantageous, thereby paving the way for effective and marketable functional foodsN/