EFFECT OF ULTRAHIGH PRESSURE TREATMENT ON VOLATILE COMPOUNDS IN GARLIC

The intact garlic samples were treated, respectively, at ambient temperature under 200, 400 and 600 MPa for 20 min, and then crushed. Their volatile compounds were extracted by solid phase microextraction and were analyzed by GC-MS and GC-olfactometry. 29, 19 and 12 kinds of volatile compounds were identified in the mentioned samples, respectively, in which alkyl sulfides accounted for 61.04%, 41.38% and 22.73% in relative peak area, while 23 kinds of volatiles in the untreated sample, 60.01% of which were alkyl sulfides. The flavor intensity of odor-active compounds decreased with the pressure increasing. The alliinase activity increased by 2.89% after treatment of 200 MPa, but decreased by 37.19% and 59.18% after treatment of 400 and 600 MPa, resulting in different flavor intensities of garlic. Therefore, it is possible to adjust formation and degradation of the volatile compounds in garlic by pressurization in order to produce garlic products with different flavor. PRACTICAL APPLICATIONS The flavor intensity of garlic has a direct correlation with the volatile compounds and alliinase activity. UHP treatment has a great effect on content, category and intensity of the volatile compounds in garlic through adjustment of alliinase activity. With the increase in pressure, the alliinase activity decreased, which greatly influenced the formation of allicin in enzymatic reaction, and then reduced the content and flavor intensity of its degradation products. Our results proved UHP treatments are useful for producing the garlic products with different flavor intensities.