Optimization of Drying Parameters for Pretreated Green Banana Slices Using Response Surface Methodology

In this study, the influence of drying temperature and pretreatment on the drying kinetics and quality metrics of green banana slices was investigated. The present investigation included the drying of 4 ± 1 mm green banana slices with potassium metabisulfite (KMS) at levels of 0 (control), 0.5%, 1%, and 1.5% in a tray dryer. A numerical optimization method was utilized to optimize the drying rate, color, water activity, rehydration ratio, and attractiveness of the banana slices, using a variety of input factors such as drying temperature and pretreatment. The results revealed that the untreated samples and those treated with 1.0% and 1.5% KMS required a longer drying time than the samples treated with 0.5% KMS. The process parameters were optimized using response surface methodology, adopting an I-optimal design for this investigation. The best solution yielded a drying air temperature of 60.62°C and a pretreatment level of 0.786% KMS, resulting in a drying time of 346.28 min, a color (L^∗) value of 76.23, a water activity (a_w) of 0.299, and a rehydration ratio of 2.81. Similar outcomes were obtained when the optimized conditions were tested and compared with experimental data using an experimental validation process.