DETERMINATION OF ANTIOXIDANT ACTIVITY AND PHYSICO-CHEMICALS CHARACTERISTICS OF FORTIFIED YOGURT POWDER BY SUPER RED DRAGON (Hylocereus polyrhizus) FRUIT PEEL POWDER Florentina Supriyanti, Zackiyah, Fiona Finandia
Chemistry Study Program
Department of Chemistry Education
UPI
Abstract
The research aims to investigate the antioxidant activity and physico-chemicals characteristics of yogurt powder fortified by peel of super red dragon (Hylocereus costaricensis) fruit. Methods include of making super red dragon fruit peel powder, making yogurt, fortification of yogurt using super red dragon fruit peel powder and freeze drying. The analysis consist of antioxidant activity with the DPPH method and Physico-chemicals characteristics includes water content by gravimetric method, ash content by ashing method and pH by potentiometric method. Produced yogurt without fortification (F0) and three fortified yogurt variants F1, F2 and F3 with 10%; 20%; 30% successive fortification. The super red dragon fruit peels had antioxidant activity 93.08% ± 2.51; powdered yogurt before fortification 15.86% ± 3.39 while F1, F2 and F3 fortified powdered yogurt were 63.69% ± 1.70 ; 76.33% ± 2.79 and 92.67% ± 1.61 respectively. The water content of powdered yogurt before fortification were greater than fortified yogurt. The ash content of yogurt before fortification and fortified powdered yogurt are greater than the value of standard ash content. The pH value of yogurt powder before fortification and fortified yogurt is in the pH range of yogurt.
Keywords: Antioxidant activity, super red dragon fruit peel, yogurt powder
