Abstract:

The free terpenoids in four Vitis vinifera varieties were studied by solvent assisted flavour evaporation (SAFE) and gas chromatography-tadem mass spectrometry (GC-MS/MS). The compounds of the grapes were extracted with vibrating extraction at constant temperature, and then the non-volatiles were removed by SAFE. The volatile compounds were concentrated with a stream of nitrogen and analyzed by GC-MS/MS. The temperature of cycle water and flow rate of the sample were optimized in SAFE procedure. In the four varieties of grapes, a total of 30 terpenoids were identified by mass spectral data from NIST05a and Kovats retention indices of the standards （RIS）or from the literature （RIL）, including 10 monoterpenoids, 18 sesquiterpenoids, 1 diterpenoid, and 1 triterpenoid. Twenty-eight terpenoids were detected in Cabernet Gernischt, and 16, 17, and 16 in Merlot, Cabernet Sauvignon, and Cabernet Fanc, respectively. A total of 17 sesquiterpenoids were identified in Cabernet Gernischt, and it was the richest among the four grapes. According to semi-quantitative method, the concentration of monoterpenoids in Cabernet Sauvignon was the highest among the four grapes, whereas the concentration of sesquiterpenoids in Cabernet Gernischt was the highest. The results showed that this method can be used to identify and quantify the free terpenoids in grapes.

Key words: free terpenoids, solvent assisted flavour evaporation, Vitis vinifera , gas chromatography-tadem mass spectrometry (GC-MS/MS)