Quality and storage-stability of high-pressure preseved green beans

The effects of high-pressure technology on naturally present microbial flora, texture, color, ascorbic acid content and peroxidase activity of whole green beans were evaluated and compared to conventional preservation techniques. High-pressure processing (HPP) and two-pulse pressure treatment (pHPP) for achieving, respectively, pasteurization and sterilization on the product quality of intact green beans were under investigation. After 1-month storage there was no significant outgrowth of microorganisms for both HPP and pHPP. Both HPP and pHPP treatment showed a large retention of firmness and ascorbic acid for green beans compared to conventional preservation methods. pHPP resulted in marked changes in greenness. During storage after pressurization or conventional processing significant changes in ascorbic acid and color occurred. pHPP resulted in more than 99 nactivation of peroxidase, whereas after HPP 76 f the initial peroxidase activity remained and further decreased during storage