High hydrostatic pressure inactivation and recovery study of Listeria innocua and Saccharomyces cerevisiae in pitaya (Stenocereus pruinosus) juice uri icon

Abstract

  • © 2018 Elsevier LtdThe high hydrostatic pressure (HHP) inactivation of Listeria innocua and Saccharomyces cerevisiae was investigated in pitaya juice subsequently stored 15 d under refrigeration to assess recovery. Juice inoculated to 7.6 ± 0.4 or 7.3 ± 0.3 log10 (CFU mL¿1) of L. innocua or S. cerevisiae, respectively, was treated at 400 to 600 MPa for 7.6 to 15 min (Tinitial = 19.5 ± 2.8 °C and Tmax = 34.6 ± 2.0 °C) following a Response Surface Design. Come-up time (CUT), defined as pressure release 1 s after reaching pressure set-point, was also evaluated. After a 400 MPa CUT treatment, no viable S. cerevisiae survivors were observed. Treatments at 550 and 600 MPa for 16 and 12 min, respectively, achieved L. innocua reductions exceeding 5-log10. No viable S. cerevisiae were observed when treated juice was stored at 4 ± 1 °C for up to 15 d. HHP appears a viable nonthermal alternative to produce a microbiologically safe and stable pitaya juice.

Publication date

  • December 1, 2018