Development of experimental devices in order to study the interactions between heat and mass transfer phenomena and thermal degradation reactions of lipids during domestic reheating of pre-fried food products

摘要

The present paper deals with the development and thermal characterization of two original experimentallaboratory devices developed in order to study thermal degradation of lipids during domestic reheating ofindustrial pre-fried products. These devices are hot-air cooking and contact heating devices (called pan-fryingif oil is added between the product and the heating surface) since these two modes of reheating are commonlyused by consumers for these types of products. When defining the specifications of these devices, it wasdecided to develop prototype devices allowing to work in perfectly controlled environmental conditions interms of heat transfer phenomena. This specification is required for experiments leading to the production offood samples to be analyzed in order to study the nature and extent of chemical reactions involved in lipidsthermal degradation reactions. It was also listed as a specification to be able to reproduce in the laboratorythe variability inherent to domestic operations, this variability being mainly due to the nature andsophistication of apparatus used in domestic conditions and the goodwill of consumer to follow reheatingconditions proposed by food product manufacturers. Results about this variability will be given in this paperconcerning both hot-air cooking and contact heating in “classical” domestic operations. The technicalities(design factors, control mode) and performances (in terms of heat transfer phenomena) of the twoexperimental laboratory devices will also be detailed in this paper.