Kinetics of moisture loss applied to the baking of snacks with pregelatinized cassava starch.

Abstract

Moisture loss kinetics is a complex process defined as the liquid removal from a solid by thermal application. The purposes of the study were to obtain kinetic curves of moisture loss during the baking of cassava snacks and establish which processes govern the moisture loss, recognize which mathematical models describe the moisture loss curves more precisely, and determine activation energy (Ea) and effective diffusivity (Deff ). Experimental data were obtained through baking at four temperatures formulations for snacks with different dehydrated cassava puree (DCP) proportions. Page's and Chávez Méndez's models showed the best fits. We calculated Deff and Ea employing the analytical solution of Fick's Second Law for the geometry of plane plates. Deff values increase with DCP but did not show a trend. The range found was from 5.22E-06 to 2.93E-05 m2 /s. The results of Ea showed that the mixture of flours produced an increase in the energy necessary to initiate the effective diffusion (24.84kJ/mol)comparedtothe samples without mixing (15.54kJ/mol). Moisture loss curves show that the diffusion process governs a large part of the process. PRACTICAL APPLICATION: Given the need to increase research for the development of the cassava industry, which currently has low competitiveness compared to less expensive products such as corn, various efforts are being made to generate new products that can replace wheat flour, at least in part. However, it is necessary to research how this substitution affects the various steps of the production system, including baking. During baking, one of the most significant processes is moisture loss. In this sense, the kinetic modeling of the moisture loss process parameters is mainly helpful in the food industry. The mathematical models of moisture loss processes are used to design new or improved baking systems or even control the process.