Multi-Objective Optimization of Vacuum Frying Process Conditions for Jackfruit Using the Restricted Area Method (RAM) With Combination Criteria R.

This study reports the development and solution of a multi-objective optimization problem using the restricted area method with Combination Criteria R, aimed at determining the optimal process conditions for vacuum frying for jackfruit. Under the optimal conditions, the obtained product simultaneously achieved the lowest possible energy consumption, while meeting the required moisture content, exhibiting an attractive bright yellow color, a crisp and porous texture, and maintaining acrylamide levels within the permissible limit. Experiments were conducted to establish five objective functions: y1 (kWh/kg) – energy consumption; y2 (%) – product moisture content; y3 – color difference index between the product and the standard sample; y4 – product porosity, y5 (µg/kg) – acrylamide content after frying, all of which depend on three process variables: Z1 (°C) – vacuum frying medium temperature; Z2 (kPa) – vacuum frying chamber pressure; Z3 (min) – vacuum frying time. Based on this, a multi-objective optimization problem (29) was formulated, solved, and experimentally validated. The results identified the optimal process conditions as: Z1 = 96.970C; Z2 = 9.65 kPa; Z3 = 18.77 min, corresponding to y1 = 2.10 kWh/kg; y2 = 2.30%; y3 = 0.88, y4 = 0.24, y5 = 76.68 µg/kg. These findings demonstrate that vacuum frying under the optimal conditions provides products with near-minimal energy consumption, desired moisture content, appealing bright yellow color, crisp and porous structure, and acrylamide levels lower than the permissible limit.