Abstract
The present study aimed to investigate the mass transfer phenomena during vacuum impregnation of Gulabjamun, specifically the migration of moisture into and fat from the product as well as sugar uptake by the product during soaking at varying levels of soaking syrup concentration (40, 50, and 60°Brix) and soaking time (2, 4, and 6 min). To describe these mass transport phenomena, mathematical models were developed using the one-dimensional transient mass diffusion equation and Crank's equation. The moisture transfer coefficient was found to decrease with an increase in syrup concentration, i.e., 1.075 × 10(-04), 8.729 × 10(-05), and 5.097 × 10(-05) m/s at syrup concentrations of 40, 50, and 60°Brix, respectively. Conversely, the fat transfer coefficient was observed to increase linearly with syrup concentration from 1.143 to 1.595 × 10(-04) m/s, and the sugar transfer coefficient increased with an increase in syrup concentration from 3.179 to 5.257 × 10(-05) m/s. The study established that the vacuum process significantly accelerated the mass transport of all evaluated entities. The models were validated at 55°Brix for 5 min at ambient temperature (30 °C) and found to provide an excellent fit to the experimental data.