Comparing the effects of high hydrostatic pressure and thermal pasteurization combined with nisin on the quality of cucumber juice drinks

The aim of this study was to evaluate the effects of high hydrostatic pressure (HHP) at 400 MPa/4 min and 500 MPa/2 min and thermal pasteurization at 85 °C/15 s with 100 IU/mL nisin on natural microbial flora, chlorophyll a and b, color, lipoxygenase activity and four C9 key odorants of (E,Z)-2,6-nonadienal, (E,Z)-3,6-nonadien-1-ol, (E)-2-nonenal and (Z)-6-nonenal in cucumber juice drinks over 50 days of storage at 4 °C. Yeast and molds (Y&M) were completely inactivated by all treatments, and their levels were below the detection limit during storage. Nisin with HHP or thermal pasteurization had a synergistic effect on the inactivation of total aerobic bacteria (TAB). For all the quality attributes studied in this article, their retention was significantly better in the HHP-treated samples than in the thermally pasteurized samples during storage. The samples treated by 500 MPa/2 min with 100 IU/mL nisin exhibited a longer shelf life as compared with other treated samples.Industrial relevanceThis research paper presents a fair comparison of cucumber juice drinks treated by HHP and thermal pasteurization which is quite scarce. The available data are provided for the evaluation and application of HHP and thermal pasteurization in the beverage industry and could be used to establish safety criteria for the commercial production of high quality cucumber juice beverages.

► Y&M in cucumber juice drinks were completely inactivated by HHP or 85 °C/15 s.
► Y&M were below the detection limit during 50 days of storage at 4 °C.
► Nisin with HHP or 85 °C/15 s had a synergistic effect on the inactivation of TAB.
► Nisin with 500 MPa/2 min could effectively inhibit the growth of TAB during storage.
► A better quality and longer shelf life could be achieved by nisin with 500 MPa/2 min.