Physicochemical and sensory quality of high antioxidant fruit leather of red dragon fruit and watermelon rind enriched with seaweed

Abstract Fruit, as a source of antioxidants and phenolic compounds, is perishable. It also has an underutilized component. Fruit leather has a long shelf life in the form of thin sheets with a distinctive texture. This study aimed to investigate the effect of seaweed ( Eucheuma cottonii ) addition on the physicochemical and sensory quality of fruit leather made from the combination of red dragon fruit and watermelon rind. The physicochemical quality was characterized by measuring the critical quality parameters of fruit leathers, including proximate analysis, water activity, total phenol, antioxidant activity, texture, and organoleptic analysis. The statistical analysis of phenolic compound activity, antioxidant activity, vitamin C, moisture content, carbohydrates, and water activity (a w ) was conducted using a one-way ANOVA test, while the analysis of ash content, protein, fat, tensile strength, elongation, and organoleptic properties was performed using the Kruskal–Wallis test. Increasing seaweed concentration significantly increased moisture, ash, protein, vitamin C, total phenol, water activity, and elongation but decreased fat content. Furthermore, the increase in seaweed concentration reduced liking toward taste and color significantly but increased texture liking. The best product was the F2 product with 10% seaweed. F2 has the following attributes: 11.07% of moisture content, 2.34% of ash, 1.53% of protein, 0.19% of fat, 84.86% of carbohydrate, 8.17 mg/100 g of vitamin C, 0.41 of water activity, 0.54 N/m2 of tensile strength, 22.22% of elongation, 107.39 ppm of IC50, 1.66 mg/GAE g of total phenolics.