Finite Element Modeling for Bi‐Directional Transport Phenomena During Vacuum Frying of Gulab Jamun: Simulations and Experimental Validations

ABSTRACT The growing consumer demand for healthier deep‐fried foods has intensified research into innovative frying technologies that can increase product quality while mitigating health risks. Conventional atmospheric deep fat frying often leads to excessive oil uptake, degradation of heat‐sensitive nutrients, and formation of underivable compounds. In this context, vacuum frying (VF) has emerged as promising alternative to obtain safe and nutritious deep‐fried foods. Therefore, this study has explored the impact of VF conditions (25 kPa, 138°C, 10 min) on bidirectional transport mechanisms, including moisture migration, oil absorption, and temperature distribution in Gulab jamun ball. A finite element method (FEM) based coupled 2D‐axisymmetric heat and mass transfer (HMT) model, developed in COMSOL Multiphysics, was employed to simulate these processes. The simulated results showed rapid surface heating to near oil temperature, while center remained slightly below 100°C. Dry basis moisture content decreased significantly, with surface moisture reducing from 0.42 to 0.05 g/g, while center declined to 0.38 g/g. Oil absorption (d.b.) progressively increased, with surface oil content increasing from 0.245 to 0.384 g/g and center achieved 0.315 g/g. Model validation showed strong agreement with experimental data (0.942 ≤ R 2 ≤ 0.994, MRE: 0.003–0.910, RMSE: 6.55 × 10 −4 −2.843, and χ 2 : 1.15 × 10 −4 −2.929). These results confirm the accuracy of the model in successfully predicting bidirectional transport dynamics. These findings provide deeper mechanistic insight into transport phenomena occurring under VF conditions and support the optimization of processing parameters for traditional dairy based confectioneries. Through reduced oil uptake and improved nutrient retention, VF contributes significant societal potential in promoting healthier fried food options, improving public health outcomes, and advancing sustainable food processing technologies.