Effects of different dragon fruit varieties and SCOBY concentration on the physiochemical, antioxidant, and sensory properties of fermented beverage with the Kombucha consortium

Abstract

Dragon fruit (Hylocereus spp.) was a favorite fruit due to its delicious taste and because it contains many nutrients that were good for health. Kombucha was a beverage that is prepared by fermenting sweetened black tea using a tea fungus (SCOBY), which was a symbiotic culture of acetic acid bacteria and yeasts. The research aimed to explore the impact of various dragon fruit varieties and SCOBY concentrations on the physiochemical, antioxidant, and sensory properties of fermented beverages using the Kombucha consortium. Dragon juice was used as a substrate for fermentation, resulting in a new beverage with the best-selected treatment. After fermentation, the best treatment results were shown on day 8 of white dragon fruit juice with scoby 5% (W5%) and red dragon fruit juice with scoby 5% (R1%). The results after fermentation showed a decrease in pH, total soluble solids, total reducing sugar, and total betacyanin, but there was an increase in total phenolic content and DPPH. The results of the best treatment method of white and red dragon fruit juice fermentation were pH (W5% = 2.70, R1% = 2.48), total soluble solids (W5%= 8.35oBrix, R1%= 13.35 oBrix), total reducing sugar (W5%= 6.54mg/ml, R1%= 9.60mg/ml), and total betacyanin (W5%= 0.05mg/100ml, R1%= 0.43mg/100ml). In addition, the results with the best treatment generally increased after 8 days, including phenolic content (W5%= 10.54 mgGAE/100ml, R1% = 12.03 mgGAE/100ml) and DPPH (W5%= 14.94%, R1%= 16.87%). In general, both types of dragon fruit showed a promised antioxidant content that was good for human health.