ABSTRACT:
The fruit of the dragon fruit (Hylocereus undatus) is famous not only for its external appearance but also for its nutritional value. The peel of dragon fruit is approximately 20-40 per cent of the weight and is normally treated as agricultural waste; however, it possesses some hidden nutritional value and is very valuable. The main message of this review is that dragon fruit peel should be used because it is both nutritionally and therapeutically significant, as well as economical. It also aims to identify the major chemical compounds found in the peel and their applications in promoting health. This review also summarizes the data of recent analytical studies where standard tools were used, including solvent extraction and HPLC, followed by chromatographic and spectroscopic methods for the identification and quantification of chemical compounds found in the peel. The analysis established that the peel of dragon fruit majorly harbors three bioactive agents: betalains, phenolic compounds, and dietary fibres. They all contain unique therapeutic properties, such as betalains, which possess strong antioxidant properties and also provide the fruit with colour; phenolic compounds, which possess antimicrobial properties; and dietary fibres, which regulate blood sugar levels and improve gut health. It has been proven that the peel of the dragon fruit is not a waste, but a powerful source of health-promoting compounds that would help to reduce the effects of pollution on the environment and foster the economic and nutritional industries