Continuous Evolved Gas Analysis and Thermal Analysis in Micro-scale Roasting of Foods

Abstract

In roasting processes of foods, non-enzymatic browning reactions lead to the formation of water and carbon dioxide. Continuous monitoring of the evolution of moisture and carbon dioxide would offer an interesting tool for determining reaction kinetics of non-enzymatic browning and optimising roasting processes. Isothermal and dynamic heating of small specimens of hazelnuts in a differential scanning calorimeter which was linked to a non-dispersive IR gas analyser presents a possibility to simulate roasting processes on a micro-scale. Formation of water and carbon dioxide was dependant on the initial moisture content of the hazelnuts, heating rate and composition of gas atmosphere (nitrogen vs. oxygen). Depending on the heating conditions, evolution of carbon dioxide is not only caused by degradation of amino acids and sugars but also by lipid oxidation.