Seaweed extracts as potential functional ingredients in yogurt

Yogurt was manufactured containing extracts (0.25% and 0.5% (w/w)) prepared from Ascophyllum nodosum (100% H₂O (AN₁₀₀), 80% ethanol:20% H₂O (AN_80e)) and Fucus vesiculosus (60% ethanol:40% H₂O (FV_60e)). Yogurt composition, shelf-life parameters, stability and bioactivity of seaweed extracts in yogurt was examined over 28 days. Yellowness ‘b*’ was higher (P < 0.05) in yogurts containing FV_60e and AN_80e. Yogurts containing AN_80e (0.5%) and FV_60e (0.5%) had lower (P < 0.05) levels of lipid oxidation. The pH, microbiology and whey separation in yogurt were unaffected by seaweed extract addition. Yogurt modulus was higher in control yogurts. Control and AN₁₀₀ (0.25% and 0.5%) yogurts were most accepted by sensory panellists. Antioxidant activity (DPPH) of seaweed extracts in yogurt was stable as a function of storage time. Yogurt and digestates did not affect the antioxidant status (CAT, SOD and GSH assays) or protect against H₂O₂-induced DNA damage in Caco-2 cells. Industrial relevance The research work and results presented in this manuscript are of high industrial importance. Yogurt and related products are some of the most commonly manufactured and consumed food products worldwide. In recent years yogurt and other dairy products have been used as carriers for functional bioactive food ingredients, or nutraceuticals. Seaweeds contain a range of bioactive compounds with reported health benefits and represent a potentially exploitable source of functional ingredients for the dairy industry. This manuscript demonstrates that extracts from Ascophyllum nodosum can be incorporated successfully into a fermented dairy product such as yogurt.