Abstract: In order to explore the effect of ultra high pressure (UHP) treatment on aroma components of strawberry juice, fresh strawberry juice was subjected to UHP treatment under different pressure levels. The volatile aromatic compounds of strawberry juice were isolated by solid-phase microextraction (SPME) and analyzed by capillary gas chromatography-mass spectrometry (GC-MS). The relative contents of aroma components were determined by area normalization method. The results showed that UHP treatment caused great changes to aroma components of strawberry juice. The predominant aroma compounds including butyric acid methyl ester, caproic acid methyl ester, caproic acid ethyl ester and 2,5-2 methyl-4-hydroxyl-3(2H)-furan ketone were increased most obviously. Thus, UHP treatment is effective in enhancing the characteristic aroma of strawberry juice. Collectively, our findings indicate that the kinds and amounts of predominant aromatic components in strawberry juice can be effectively retained or even increased during 25 min of UHP treatment at 300 MPa. In conclusion, UHP treatment holds promise as a cold processing technique for strawberry juice.

Key words: strawberry juice, solid-phase microextraction, ultra high pressure, aroma components, GC-MS