Proposta de utilização de módulo termoelétrico para avaliação térmica

Abstract

Thermal analytical methods has been studied since the early twentieth century and with technological advancement of instrumentation and discovery of the applications of the applications in various sectors of scientific and industrial production make this branch gained prominence. From the existing thermal methods of analysis the measurement and study of transition phases in foods Differential Scanning Calorimetry method (DSC). The glass transition is a phase transition to second order characterized by the passage of a crystalline compound of the organized state to an amorphous state, which molecules lose their organizational arrangement and pass to a random structure. A thermoelectric module may be characterized by the joining of two ceramic plates which cover the electrical conductors of an electric current through conductive heat exchange occurs between the plate surface generating a heat pump by the Peltier effect. This work aimed to evaluate the glass transition lyophilized guava pulp using the thermoelectric module replacement methodology to DSC. Four samples were prepared containing different sucrose additions (0%, 5%, 10% and 20%). The samples were lyophilized and subsequently held in thermoelectric module analyzes to determine the glass transition thereof. The thermograms obtained by the thermoelectric module showed noise along the analyzes that hampered the analysis of the glass transition range of samples. The noises presented arose module operating behavior and pass the limits of current and DC voltage accepted by the module. It was proposed a study to detect specific regions module for identifying points capable of fixing the sensors to more homogeneous temperature measurements.