Watermelon rind powder: Composition, functional properties, and applications in aquaculture

Mendes J.A.C.; Silva T.E.F.D.; Rocha P.L.O.; Morey G.A.M.; Anable R.N.F.; Viana D.C. · Food and Humanity (2026) · DOI: 10.1016/j.foohum.2026.101312

Resumen

Agro-industrial residues from fruits and vegetables are sustainable sources of bioactive compounds with antioxidant and antimicrobial properties, supporting circular economy strategies in animal production systems. In aquaculture, these by-products are investigated as functional feed ingredients capable of partially replacing conventional protein sources while enhancing fish health and performance. Watermelon (Citrullus lanatus) rind, accounting for 30–40% of fruit mass, is rich in phenolics, polysaccharides, vitamins, minerals, and amino acids. Processed into watermelon rind powder (WRP), these compounds have been linked to improved growth, feed efficiency, immune modulation, and oxidative balance in fish such as Oreochromis niloticus, Cyprinus carpio , and Labeo rohita . Evidence indicates that WRP inclusion does not induce oxidative stress and enhances antioxidant defense systems, including superoxide dismutase, catalase, and glutathione peroxidase, thereby reducing lipid peroxidation and maintaining physiological stability. In Labeo rohita , high dietary inclusion confirmed the absence of oxidative stress, supporting its physiological safety. Functional outcomes also include improved immunity and survival. Supplementation with watermelon-derived ingredients increased survival in Nile tilapia challenged with Streptococcus agalactiae from 30% in controls to 83.3% in treated groups, indicating strong immunoprotective effects. This review synthesizes current knowledge on composition, processing, mechanisms, and aquaculture applications of WRP. However, variability in species, experimental design, and inclusion levels limits comparability across studies. Regulatory agencies (EFSA, FDA, Codex Alimentarius) have not yet specifically approved WRP as a feed ingredient, reflecting a lack of harmonized guidelines. Economic assessments suggest solar drying is more cost-effective than oven drying despite longer processing time. Overall, WRP is a promising aquafeed ingredient requiring standardized protocols, species-specific validation, and further economic and regulatory evaluation.

Instituciones: Universidad Nacional de la Amazonía Peruana