The impacts of peel inclusion and fermentation temperature on the bioactive compounds, antioxidant activity, and sensory properties of dragon fruit wines.

Background: Even though dragon fruit peel has more health benefits than its pulp, it is considered to be waste after fruit processing. In this study, dragon fruit peel was explored as an additional ingredient in winemaking.

Methods: The contents of total phenolic compounds, betacyanins and ascorbic acid, the antioxidant capacity by DPPHž method, and the level of consumer acceptability of the wines prepared from two species with and without peel were compared.

Results: The wines of the H. polyrhizus species contained much higher total phenolics (1.4-1.6 times), betacyanins (75-81 times), and vitamin C (2.8-3.8 times), as well as higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (1.2 times) than the wines of H. undatus. Although the fermentation process led to the degradation of betacyanins, it increased the total phenolics (up to 17%), vitamin C (up to 24%), and DPPHž scavenging activity (up to 19%) as compared with the control when fermentation was conducted at 25°C, which was found as the most suitable fermentation temperature to produce wines with the highest quality in terms of antioxidant content and activity. At this temperature, peel inclusion also increased these values in the wine. In addition, the sensory properties in terms of appearance and aroma could be improved in the final fermented product.

Conclusions: H. polyrhizus wine might have higher antioxidant properties than H. undatus wine. With a suitable fermentation temperature, peel inclusion as an ingredient could enhance these characteristics of the wine without compromising its sensory quality. This study may provide insights into fruit winemaking with higher health benefits.