Kinetics of “Laba” garlic greening and its physiochemical properties treated by Dense Phase Carbon Dioxide

- DPCD accelerated garlic greening and reduced the processing time of “Laba” garlic.
- Changes of absorbance were well fitted to a zero-order kinetic model.
- Vinegar-pickling treatment was important to get necessary sensory qualities.

The production of Chinese traditional and popular “Laba” garlic is limited to its homemade method. In this investigation, the technology of Dense Phase Carbon Dioxide (DPCD) was employed to produce this product for the first time. The greening, physiochemical properties and sensory quality of “Laba” garlic processed by this method were analyzed, respectively. Absorbance changes at 590 nm and color indices including L*, a*, b* and H° consistently showed that DPCD had significant effect on garlic greening. Changes of absorbance at 7, 10, 13 MPa (55 °C) and at 45, 55 °C (10 MPa) were well fitted to a zero-order kinetic model. Analysis of physiochemical and sensory properties comparing “Laba” garlic processed by the traditional method and DPCD treatment were performed. Results showed that vinegar pickling for 24 h after DPCD treatment significantly increased the consumers' acceptance of color, flavor and taste. This investigation illustrated that DPCD treatment greatly accelerated the greening reaction of “Laba” garlic and shortened its processing time. This treatment could become an alternative to the longer traditional method.