Valorisation of dragon fruit peel in functional squash

Dragon fruit (Hylocereus spp.) peel is a waste product rich in bioactive components. This study developed and evaluated three experimental formulations of functional dragon peel squash with different acidulants, nutritional values, and sensory profiles. The acidulants were amla juice, citric acid, and lemon juice. The experimental samples were compared with the control sample and analyzed using standard methods, which included the proximate analysis, the Folin-Ciocalteu assay for phenolics, the DPPH assay for antioxidant activity, and a nine-point hedonic scale for sensory evaluation. The color degradation was evaluated over three successive one-week storage intervals. The proximate composition (wet basis) showed that the peel consisted of 92.81% moisture, 1.49% ash, 0.528% protein, 0.20% fat, and 4.9% carbohydrates. The squash showed 40–47°Brix of total soluble solids, pH 2.32–4.83, 0.18–1.5% titratable acidity, and ≤ 108 mg/100 mL ascorbic acid. The sample with amla juice possessed the highest phenolic content (5.20 mg GAE/100 g) and the control has highest antioxidant level (IC50 = 0.725 mg/mL), as well as the lowest microbial load (1.3×10³ CFU/mL) after three weeks of storage. As for the sensory assessment, the amla juice sample was preferred for color and aroma, while the sample with lemon juice received a higher score for taste. The ANOVA test (df = 2.4) showed a stable L* over 21 days, whereas the b* values tended to increase in all four formulations, and the a* value increased in the sample with lemon juice (p < 0.05). The significant change in b* indicated poor storage stability, which is to be improved by reformulation with color stabilizers. In this research, dragon fruit peel was converted into a nutritious and organoleptically attractive squash. This functional beverage offers a sustainable strategy for valorizing agricultural waste.