Effect of high hydrostatic pressure (HHP) treatment on flavor, physicochemical properties and biological functionalities of garlic

- The effect of high hydrostatic pressure (HHP) treatment on various properties of garlic.
- Biological activities of HHP treated garlic samples decreased compared with control.
- A profile of garlic flavor can be modified by HHP treatment.
- Color, the cohesiveness and hardness decreased after HHP treatment.
- Alliinase activity is dramatically changed at a higher HHP reaction time.

The characterization of flavor, physicochemical properties and biological activities of garlic extracts prepared by high hydrostatic pressure (HHP) treatment (500 MPa) was conducted at various HHP reaction times and pH conditions. The evaluation of flavor revealed that HHP treated garlic samples in acidic condition (pH 1.8-3) were most effective to reduce the pungent flavor of garlic among all conditions.After HHP treatment, the hardness and color values of L*(lightness), a*(redness), and b*(yellowness) of garlic samples decreased, while the cohesiveness value of garlic samples was increased (P < 0.05). The antioxidative, antimicrobial and antitumor activities of HHP treated garlic samples were decreased compared with control. A rapid decrease in antimicrobial and antioxidative activities was observed over 3 min HHP reaction time. No antitumor activities were observed after 3 min HHP reaction time. Up to 56 s HHP reaction time, the alliinase activity was not changed significantly but it was dramatically decreased at a longer HHP reaction time compared with control (P < 0.05), showing higher stability in acidic condition than alkaline condition. Based on present observations, this study supports high potentials of HHP treatment to produce new value-added garlic products with modified garlic flavor profile, and minimized physicochemical properties and biological activities.