Response Surface Methodology for Optimization of Glucuronic Acid Production Using Kombucha Layer on Sour Cherry Juice

The optimum conditions for the glucuronic acid production (the important key component for its detoxifying action through conjugation to the xenobiotic metabolism of the substances in liver) using kombucha layer on sweetened sour cherry juice were determined using response surface methodology. Kombucha layer involving a symbiosis of osmophilic yeast species and acetic acid bacteria that convert a very simple substrate to a slightly carbonated, acidic, refreshing beverage with high pharmaceutical and nutritional value. A central composite rotatable design, consisting of seventeen experiments was used to investigate the effects of three independent variables, namely sucrose content, temperature and the cultivation time on five responses: glucuronic acid (g/L), pH value, remained sucrose (g/L), reducing sugar (g/L), and total acidity (g/L). Statistical analysis of the obtained results, depicted that all the factors had a significant effect which leads to glucuronic acid concentration upto maximum 132.5 g/L at 37 °C within two weeks of fermentation process on 8% sucrose-sweetened sour cherry juice.