Analysis of Aroma Compounds in Red Fragrant Pear by Headspace Solid Phase Micro-extraction and Gas Chromatography-Olfactometry-Mass Spectrometry.

The aroma compounds in red fragrant pear were analyzed by headspace solid phase micro-extraction (HS-SPME)and gas chromatography-olfactometry-mass spectrometry (GC-O-MS). The extraction conditions of aroma components in red fragrant pear were systematically optimized by response surface method. The aroma components were identified based on chromatographic retention index and mass spectrometry analysis and olfactometry and the contribution of aroma substances to the relative odor activity values was evaluated. The optimal extraction efficiency was achieved under the following conditions: 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) SPME fiber, 2.9 g of sample, extraction time 46 min, temperature 64 °C, equilibrium time 30 min and desorption time 4 min. The results showed that a total of 127 compounds were detected, 76 compounds of which were structurally identified, accounting for 97.36 % of the total volatile substance. These compounds included 18 esters, 9 aldehydes, 13 alcohols, 12 alkenes, 4 ketones, 11 hydrocarbons, 9 other compounds. According to the result of olfactometry and relative odor activity value (ROAV), the main flavor volatile components were identified: ethyl acetate; hexanal; ethyl hexanoate; hexyl acetate; ethyl -2 -trans -4 -cis -decadienoate; nonanal; trans -2 -hexenal; ethyl caprylate; ethyl caprate; alpha-farnesene; phthalic acid diisobutyl ester. [ABSTRACT FROM AUTHOR]