Abstract
Cellulose is a carbohydrate polymer that is readily available from plant and produced by variety of bacteria such as Komagataeibacter xylinus through fermentation. However, bacterial cellulose has higher purity and water holding capacity than plant-based cellulose and can potentially be used as an active gel in food applications such as anti-browning gel. Expired cordial drinks could be an excellent fermentation medium for bacterial cellulose production due to its high sugar content and simultaneously mitigate wastewater issues. Therefore, the objective of this research was to produce bacterial cellulose as anti-browning gels from expired cordial drinks in fresh apple juice model system. The first stage of the study was to compare the production of bacterial cellulose from expired cordial drinks without and with the addition of yeast extract. Results of cordial with the addition of yeast extract showed the highest wet weight of cellulose with 140 g/L, decreased in pH value by 1.72, and decreased of sugar and protein concentrations by 12.44 mg/ mL and 0.93 mg/mL, respectively, after 14 days. The produced cellulose pellicle was then used as anti-browning gel (addition of 0.1 % ascorbic acid) in the second stage of this study. Results showed that the browning index in apple juice containing the anti-browning cellulose gel has successfully prevented browning in apple juice (15.01) compared to the browning index in a control apple juice (25.58). In conclusion, bacterial cellulose can be produced from expired cordial drinks and has potential as an anti-browning gel to reduce enzymatic browning in fresh apple juice.