The Phytochemical and Antioxidant Characteristics of Fermented Jackfruit (Artocarpus heterophyllus L.) Leaves Using Single and Mixed Starter Culture

The phytochemical and antioxidant properties of fermented jackfruit leaves, using yeast and acetic acid bacteria, individually or in combination during 6 days of fermentation were investigated in the present study. Changes in pH, total reducing sugar, ethanol, acetic acid, total phenolics and flavanoids content were examined. A number of antioxidant activities such as ferric reducing antioxidant power (FRAP) and DPPH free radical scavenging activities were comparatively tested to determine the differences in the respective properties during the fermentation process. Results obtained demonstrated that there were differences in the phytochemical and antioxidant properties of fermented jackfruit leaves, depending on the fermentation starters. Fermented leaves using acetic acid bacteria alone, exhibited higher total reducing sugar (6.89 mg glucose/mL) compared to others. The ferric-reducing activities of fermented jackfruit leaves showed an increasing trend in the yeast fermentation process (5.96-10.12 mg ascorbic acid equivalent/mL). Generally, all extracts of fermented jackfruit leaves exhibited stronger DPPH radical scavenging activity except in the total phenolics and flavonoids content, whereby it showed a decrease trend throughout the fermentation process.