Improving the Antioxidant Profile of Yoghurt Using Red Seaweed Gracilaria sp.

Department of Fisheries Product Technology, Faculty of Fisheries and Marine Sciences, Mulawarman University, Samarinda, East Kalimantan, Indonesia, 75123

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Abstract

This study investigated the potential of Gracilaria sp. as a functional ingredient for yoghurt, focusing on its impact on consumer acceptance and its antioxidant capacity. The research employed a Completely Randomized Design (CRD) with three concentrations of added Gracilaria sp. ( 10%, 20%, and 30%). Key parameters analysed included pH, viscosity, total lactic acid, and proximate composition. Crucially, the antioxidant activity was evaluated using the DPPH free radical scavenging assay, and consumer acceptance was assessed through sensory evaluation. The results showed that increasing the concentration of Gracilaria sp. had a significant effect on all observed parameters. As the seaweed concentration increased, there was a notable increase in pH (acidity) and antioxidant activity. Conversely, the viscosity and total lactic acid content tended to decrease. Yoghurt fortified with 20% Gracilaria sp. was identified as the most desirable product, achieving the highest consumer preference score. This specific formulation exhibited an optimal balance of quality attributes, including a pH of 3.76, a viscosity of 270 cP, and a robust antioxidant activity of 42.74%. This research confirms that Gracilaria sp. can be effectively incorporated into yoghurt to create a functional food product with enhanced antioxidant properties. The 20% concentration proved the most effective and demonstrated high consumer acceptance.