Bioactive compounds of dragon fruit peel: roles of phenolics, flavonoids, tannins, betalains and vitamin C in modulating fish growth, antioxidant defense, and immunity: a sustainable nutraceutical approach for enhancing aquaculture health and disease resistance

Abstract

Dragon fruit peel, an agro-industrial by-product, has gained considerable attention across various sectors, including aquaculture, due to its rich composition of functional compounds beneficial to aquatic animals. This review focuses on the major bioactive phytochemicals present in dragon fruit peel, namely phenolic compounds, flavonoids, tannins, and betalains, along with the essential nutrient vitamin C. It provides a comprehensive overview of these components, including their chemical characteristics and functional roles in fish nutrition when incorporated into diets. In addition, the effects of dragon fruit peel supplementation in aquaculture are discussed based on findings from various studies to enhance current understanding. Collectively, these bioactive constituents have been reported to improve growth performance, enhance feed utilization, strengthen antioxidant defence systems, and promote intestinal health through modulation of gut microbiota and immune-related pathways.