Abstract:

Dense-phase carbon dioxide processing (DPCDP) is proposed as an alternative technique to conventional heat sterilization in food industry, which is carried out at pressure less than 100 MPa and moderate temperature. Microorganisms are inactivated due to cell burst in liquid culture with a sudden release of pressurized CO2, inactivation of enzymes or other sterilization mechanisms. Meanwhile, this technique exhibits no side effects on flavor, taste and nutrients; moreover, it is characterized by lower energy consumption, less cost for processing and industrial equipments, and no toxin production. Although DPCDP can be used for sterilization of vegetable bacteria, it is difficult to sterilize bacillus by DPCDP at the moderate temperature condition. Moreover, previous reports related to DPCDP for vegetable bacteria mainly focused on sterilization experiments on designated medium such as buffer or broth. However, the sterilization effect of DPCDP on vegetable bacteria is affected by medium so that it is still far away from practical applications. The inactivation mechanism of DPCDP for vegetable bacteria is still not clear as yet. Similarly, its sterilization mechanisms for bacillus have rarely been investigated. In order to further develop DPCDP for the sterilization of vegetable bacteria and bacillus, and provide theoretical evidences for industrial applications of DPCDP, mechanisms and synergistic strategies for the enhanced effect of DPCDP on the treatment to heatsensitive apple juice are reviewed in this paper, which also suggests that urgent problems such as sterilization mechanisms of acidification and extraction, sterilization mechanisms for bacillus, and synergistic strategies for DPCDP need resolving as soon as possible.

Key words: dense-phase carbon dioxide (DPCD), sterilization, acidification, extraction, bacillus