An Osmanthus and Black Tea-containing Ice Jelly Formulation Optimized by Response Surface Method

Objective Bingfen (ice jelly), a popular dessert native to Southwest China, was formulated with osmanthus and black tea to create a new leisure food product.

Method Using black tea, dried osmanthus, ice jelly powder, and brown sugars syrup, an ice jelly was optimally formulated with single factor test and Box-Behnken response surface design. Sensory evaluation on texture, flavor, aroma, and taste was conducted on the prototypes. A quadratic multiple regression model was established to correlate the formulation and eating quality of the product using Design-Expert 8.0.6 followed by an analysis of variance.

Result The optimized dessert item was formulated with 1.91% ice jelly powder, 2.22% dried osmanthus, 0.09% black tea, and 0.77% brown sugar syrup to mix in with 500 g water. The bright golden colored ice jelly had a smooth appearance, delicate taste, elastic texture, moderate sweetness, and delightful osmanthus and black tea aroma that received an overall quality score of 86.7 by the sensory panel.

Conclusion The sensory rating of the ice jelly product was slightly deviated from the predicted score by the quadratic multiple regression model. Otherwise, the experimental data fitted well with the mathematic equation.