Utilization of Red Dragon Fruit (Hylocereus polyrhizus) Peel Extract as an Antioxidant in Cow’s Milk Kefir

Pemanfaatan Ekstrak Kulit Buah Naga Merah (Hylocererus polyrhizus) sebagai Antioksidan pada Kefir Susu Sapi

Abstract

Kefir, a fermented beverage rich in probiotics, exhibits antioxidant properties capable of neutralizing free radicals. To enhance its antioxidant activity, this study utilized extract from red dragon fruit peel (Hylocereus polyrhizus), which is abundant in polyphenols, as a natural antioxidant source. This extract is expected to improve the antioxidant efficacy of cow milk-based kefir. The research aimed to evaluate the impact of adding red dragon fruit peel extract on the antioxidant activity and chemical parameters of cow milk kefir. The methodology involved producing kefir with varying extract concentrations (0.002%, 0.1%, 0.2%), assessing antioxidant activity via the DPPH (free radical scavenging) method, and conducting chemical analyses including pH, protein content, fat content, and lactic acid levels. Results revealed that control kefir (no extract) had an IC₅₀ of 93.96 µg/mL, pure peel extract 19.96 µg/mL, kefir with 0.2% extract 29.61 µg/mL, 0.1% extract 37.28 µg/mL, and 0.002% extract 75.47 µg/mL. Extract supplementation also yielded pH 4.51, protein 3.84%, fat 5.67%, and lactic acid 1.24%. Overall, incorporating red dragon fruit peel extract successfully boosted the antioxidant potential of cow milk kefir while producing a product with chemical profiles meeting quality standards, positioning it as a promising functional food candidate