Effects of Processing on Tomato Bioactive Volatile Compounds

This study utilized a dynamic headspace sampling with thermal desorption protocol to study the effects of processing on volatile flavor components of tomato juices, and confirmed the presence of numerous previously reported tomato flavor compounds. Aldehydes, alcohols, esters and hydrocarbons were more characteristic of fresh tomato products and decreased in concentration in the heat-treated juice, while the concentrations of sulfur-containing and heterocyclic compounds increased with heat-processing. Results also indicated that volatile substances characterizing fresh tomato juice flavor derive mainly from the metabolism of fatty acids and amino acids, and breakdown of carotenoids. Heat-generated aroma and flavor constituents, on the other hand, arise predominantly from Maillard reactions, caramelization, and from the degradation of lipids, vitamins, pigments and other tomato constituents. The mechanisms of formation of some of these compounds are discussed.