Production of Stevia-Based Persimmon Fruit Leather by Microwave Oven and Its Optimization With Response Surface Methodolog

The consumer preference for low-calorie and nutritious foods has urged the attention of researchers and food designers to develop food products with alternative organic ingredients. For the first time, persimmon is successfully developed into fruit leather (pestil) using a non-caloric stevia sweetener. The study started with the production of persimmon (Diospyros kaki) leather, initially evaluating the compatibility of non-caloric stevia (S_T) sweetener with hydrocolloids (corn starch, pectin, and guar gum) by the hot air oven method, in which guar gum exhibited superior flexibility. After setting the leather recipe, the trials were performed in a microwave oven by employing a Box–Behnken experimental design to optimize the drying process. Independent variables including microwave power (MP), microwave time (MT), and leather thickness (LT) have shown their optimum values at 210 W, 30 min, and 3.5 mm, respectively, based on physicochemical analyses focusing on moisture content, texture, color, total phenolic content (TPC), and antioxidant capacity (AC). MP had the most substantial impact on the variables, followed by MT, while LT showed the least influence. Optimized development of microwave products emphasized better physicochemical attributes, highlighting the energy-efficient nature of the resulting product in comparison to hot air-dried product. Sensory evaluation favored the optimized microwave-dried product over the hot air oven leather products. Therefore, utilizing novel processing technologies like microwave drying is recommended for producing functional (S_T) based persimmon leather to uphold superior product quality.