| dc.description.abstract | Kombucha is a healthy fermented drink made from sweetened tea fermented with yeast
and bacteria, known for its health benefits. The project aimed to develop a beverage using
passionfruit and custard apple juice as a substitute substrate. While custard apples offer
sweetness and health benefits, their limited availability and short shelf life pose
challenges. Passion fruit, with its antioxidant properties and appealing aroma, is a valuable
addition to beverage and food formulations. This study assessed the impact of
fermentation duration and varying mixing ratios of custard apple and passion fruit juice
(0:100 (v/v), 25:75 (v/v), 50:50 (v/v), 75:25 (v/v), 100:0(v/v)) on the qualities of
kombucha-derived mixed juice. Evaluation criteria included physiochemical properties,
antioxidant capacity, and sensory profile. The results indicated a consistent pH decrease
(3.19 ± 0.03 to 3.90 ± 0.05) and rising total acidity (860.00 ± 12.55 to 1490.00 ± 17.30
mg/L) across all five samples, suggesting normal fermentation. After fermentation, total
phenolic content rose across all five samples, ranging from 339.62 ± 0.72 mgGAE/L
(SA50:PF500) to 391.4 ± 26.4 mgGAE/L (SA0:PF100), with higher passion fruit juice
percentage yielding higher phenolic levels. Passion fruit juice dominance increased
flavonoid concentration after fermentation, contrasting with decreases in other samples
(570 ± 26.5 to 1110.00 ± 40.7 mgRE/L). At the finish of fermentation, the increase decrease in bioactive chemicals influenced both DPPH radical scavenging activity
(decreasing) and ABTS radical scavenging activity (increasing). Increasing the amount of
passion fruit juice in the mixing ratio resulted in a higher aroma score due to passion fruit
juice ester compounds, as well as a higher appearance score due to passion fruit juice's
color pigment. The results obtained demonstrated that combining custard apple and
passion fruit juices could be a viable option for creating fermented beverages using
kombucha consortium. Besides, 5-day fermentation period sufficed for chemical
evaluation without taste panel barriers, and samples with 100% passion fruit juice provide
a good sensory profile, attractive aroma, contain high content of bioactive compounds,
and still high antioxidant capacity. Furthermore, fermentation was found to impact the
physicochemical and sensory characteristics of the juices. | en_US |
