Abstract:

Youdoujiao (Phaseolus vulgaris L. var. chinensis Hort) is an excellent cultivar group of snap bean which grows
in the special natural geographical environment in northeast China. In this study, headspace solid phase microextraction
(HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) technique was applied to analyze the
volatile compounds of unprocessed and cooked Youdoujiao pods. The results indicated that the main volatile compounds
of Youdoujiao were aldehydes, alcohols, ketones, acids, esters, hydrocarbons, furans and ethers. Forty-eight volatile
compounds were identified in the unprocessed pods, mainly including 2-hexenal (40.01%) 1-hexanol (12.64%) and hexanal
(11.40%). These three compounds contributed to the odor of green pods together with 3-hexen-1-ol, (E)-2-hexenal, (E,Z)-
2,6-nonadienal, 3-methyl-1-butanol, 2-ethyl-1-hexanol, (E,E)-2,4-hexadienal, (E)-2-nonenal, 2,6,6-trimethyl-1-cyclohexene-
1-carboxaldehyde, and tetradecanal. Twenty-six volatile compounds were identified in the cooked pods. The major
compound was 1-octen-3-ol, accounting for 48.77% of the total volatile components, which contributed to the aroma of
cooked Youdoujiao pods in combination with (Z)-4-heptenal, 3-(methylthio)-propanal, (E)-2-heptenal, (E)-6,10-dimethyl-
5,9-U-ecadien-2-one, octanal, and nonanal.

Key words: Youdoujiao (Phaseolus vulgaris L. var. chinensis Hort.), headspace solid phase microextraction (HS-SPME);gas chromatography-mass spectrometry (GC-MS), volatile compounds