Analysis of flavor volatiles of glutinous rice during cooking by combined gas chromatography–mass spectrometry with modified headspace solid-phase microextraction method

A combined gas chromatography–mass spectrometry (GC–MS) with modified headspace solid-phase microextraction (SPME) method, with the headspace inside a designed sampling apparatus instead of in a vial, has been employed for the analysis of the flavor volatiles of glutinous rice during cooking. All of the free flavor volatiles, the bound flavor components and the compounds formed by the thermal decomposition of the non-volatile constituents existing in rice could be liberated during the cooking process. Therefore, a broad range of the flavor volatiles of glutinous rice during cooking could be extracted, concentrated and identified in a single headspace SPME/GC–MS run. Altogether, 96 volatile compounds were identified, of which 27 components have not been previously reported in rice. A total of 86, 90 and 94 peaks, respectively, were assigned to Tatsukomochi, Kinunohada and Miyakoganemochi during cooking. The volatile components identified in the three glutinous rice cultivars during cooking belong to the chemical classes of aldehydes, ketones, alcohols and heterocyclic compounds, as well as fatty acids and esters, phenolic compounds, hydrocarbons, etc.