Study of vitamin C level of soursop leaves (Annona muricata l.) and galactomannan utilization in kombucha during fermentation

The Vitamin C level of Soursop leaves Kombucha using galactomannan as a food source of acidic bacteria in Kombucha was investigated. The aimed of this study was focused on evaluating the vitamin C content in the Kombucha during fermentation for 14 days using indophenol titration method. Soursop Leaves were prepared by drying the fresh leaves in the oven at 70°C for 3 hours and Galactomannan was obtained by centrifugation process of endosperm of Arenga pinnata in neutral condition. Inoculation of the soursop leaves kombucha was performed by 20% (v/v) from previous kombucha broth and the samples with different concentration 0.5%(w/v), 1%(w/v) and 1.5%(w/v) were analyzed after 0, 7 and 14 days with 3 replications respectively. The results showed that there was a significant influence of concentration of soursop leaves and time duration during fermentation. The highest level of Vitamin C present in 1.5% (w/v) soursop leaves when fermented it for 14 days (3.3094 ± 0.439 mg/100 mL) and the lowest level of Vitamin C present in 0.5%(w/v) soursop leaves towards 0 days fermentation (0.3214 ± 0.067 mg/100 mL). Process duration and concentration of the leaves were the main factor influencing the content of Vitamin C of Kombucha.