Optimization of producing functional sponge cake using a combination extract of green tea, white tea, and ginger

Plant extracts play an important role in improving the quality properties and enhancing the shelf life of food prod-ucts. In the present study, different concentrations of green tea (0-2%), white tea (0-2%), and ginger (0 to 1.5%) extracts were used to formulate a sponge cake. Response surface methodology was used to investigate cake quality attributes. For each response, a second-order polynomial model with high coefficient of determination (R2; >0.95) was developed using multiple linear regression analysis. The overall optimum area with high stability was found at a combined level of green tea (1.44%), white tea (1.71%), and ginger (0.75%) extracts.