Tushar Gulati

Modeling moisture migration in a multi-domain food system: Application to storage of a sandwich system

Moisture transport in a food system involving two different materials of unequal moisture content was modeled with water activity as the driving force using a porous media framework. This model was applied to a bread-barbecue chicken pocket sandwich stored in isothermal conditions. The model successfully predicted the equilibrium condition, where the two materials, bread and chicken, reached the same water activity, but not the same water content. The transient changes in the moisture content in the bread and chicken were predicted and shown to be significantly affected by air gap between the bread and chicken. The prediction process was also sensitive to the Darcy permeability values for the materials. The modeling framework presented for a sandwich system is very general and can easily be extended to other multicomponent food systems.

Bivariate characterization and measurement for effective permittivity of esterification reactions at 2450 MHz for multiphysics simulation

The aim of the present work is to obtain effective permittivity of the reaction mixture during esterification reac- tions that can be used in a dynamic simulation environment and analysis the dielectric properties during the reaction process. Microwave heating serves as an excellent tool for carrying out such reactions and the multiphysics simulations need effective permittivity as one of the most important inputs. In this work, we perform the esterification reaction between ethanol, acetic acid and butyric acid using a temperature cycle in order to measure the effective permittivity of the reaction mixture. The ob- tained result is fitted using a bivariate function of the concentration of one of the products of the reaction and temperature of the mixture. The computed results show good agreement with measured values with maximum errors for the synthesis reactions of ethyl butyrate and ethyl acetate being 4.94% and 3.68%, respectively.

Engineering puffed rice

Sophisticated materials science lies behind the fabrication of the crunchy, low-fat food enjoyed in cereals and snacks worldwide.