Optimization of a Process for Juice Extraction from Banana Puree Using Freezing Treatment Combined with Pectinase-Based Hydrolysis

The purpose of this study is to optimize technological factors controlling pretreatments of banana puree products derived from Vietnamese banana for extraction of high-quality banana juice. These pretreatments included freezing, followed by pectinase-based hydrolysis with controlling parameters of freezing temperature, hydrolysis temperature, and hydrolysis time. A small central composite design (SCCD) was chosen for investigation and optimization of the effects of freezing temperature (−30°C to −20°C), enzyme hydrolysis temperature (45–55°C), and time (150–210 minutes) on recovery efficiency (%), clarity (%T), and sensory quality (score) of puree banana juice. Data revealed that the three targeted variables displayed significant influences on all responses. Moreover, mathematical quadratic models of juice recovery efficiency, clarity, and sensory quality yielded regression coefficients of 0.9963, 0.9865, and 0.9902, respectively, demonstrating a high fitness of the predicted and experimental data from different combinations of freezing temperature, hydrolysis temperature, and hydrolysis time. The process parameters were numerically optimized using Design-Expert software for maximization of juice recovery efficiency, clarity, and sensory quality. The optimal technological parameters were freezing temperature of −25°C, hydrolysis temperature of 50.21°C, and hydrolysis time of 180.42 minutes, under which juice recovery efficiency, clarity, and sensory quality were predicted of 55.16%, 98.47%T, and 18.9 points (total soluble solids content of 28.9 °Brix). Banana juice recovery efficiency, clarity, and sensory quality measured from confirmatory experiments were 54.78 ± 0.85%, 98.11 ± 0.75%T, and 18.65 ± 0.27 points, which differ from modeled values of −1.32% to −0.37%, demonstrating the reliability and accuracy of the established models. The quality of banana juice obtained in this study is superior to that reported in the literature, particularly sensory quality.