Physicochemical quality of fermented milk with additional red dragon fruit (Hylocereus polyrhizus) skin

Abstract

Physicochemical qualities and total flavonoids qualities of fermented milk can be enhanced by the utilization of natural ingredients of red dragon fruit skin (Hylocereus polyrhizus). The purpose of this study was to analyze the effect of red dragon fruit skin concentration and length of incubation as well as their interaction toward physicochemical characteristics and total flavonoid qualities of fermented milk with the addition of red dragon fruit skin. The research method used was an experimental method by using a completely randomized design with 2 two factors. Factor A was the dragon fruit skin concentration 0%, 20%, 40%, and 60% and factor B was the incubation period ranging from 12 hours, 14 hours, until 16 hours. The treatments were repeated three times each. The data were processed statistically with analysis of variance followed by the least significant difference test. The result showed that a high concentration of red dragon fruit skin and long incubation could increase the activity of Lactic Acid Bacterial (LAB) during the fermentation process, so it increased the fat content but decreased carbohydrate and protein content of fermented milk. Therefore, it can be suggested that the concentration of dragon fruit skin used in producing fermented milk should be 60% and take 12 hours.