High pressure processing of milk: Modeling the inactivation of psychrotrophic Bacillus cereus spores at 38–70 °C

Modeling the inactivation of psychrotrophic Bacillus cereus spores in beef slurry by 600 MPa HPP combined with 38–70 °C: Comparing with thermal processing and estimating the energy requirements

“…A c c e p t e d M a n u s c r i p t 13 spores, and in our previous results carried out with the same strain in milk (Evelyn and Silva, 2015b). After 20 min 600 MPa at 70°C 4 log reductions were obtained in milk (Evelyn and Silva, 2015b) which was lower than 4.9 log obtained with beef slurry in our current study.…”

“…HPP relies on the use of high pressures (typically 400-600 MPa) to process liquid and solid foods (with or without heat) between 5 and 10 min, to inactivate spoilage/pathogenic microorganisms and to extend food shelf-life. High pressure treatment at room temperature is not sufficient for reduction of bacteria and mould spores (Evelyn and Silva, 2015b, 2015c, 2016Evelyn et al, 2016;Silva et al, 2012), in which some may resist pressures higher than 1000 MPa. HPP at ambient temperature can also have limited effectiveness for the inactivation of endogenous food spoilage enzymes, namely polyphenoloxidase (Sulaiman and Silva, 2013; Page 5 of 36 A c c e p t e d M a n u s c r i p t 5 2015).…”

“…HPP at ambient temperature can also have limited effectiveness for the inactivation of endogenous food spoilage enzymes, namely polyphenoloxidase (Sulaiman and Silva, 2013; Page 5 of 36 A c c e p t e d M a n u s c r i p t 5 2015). Therefore, combination of HPP with a mild thermal process is required (Evelyn and Silva, 2015b, 2015c, 2016Evelyn et al, 2016;Patterson 2005;Silva et al, 2012). This process is commonly referred as HPP-thermal or high pressure thermal process (HPTP).…”

“…nisin and sucrose laurate), or an additional control hurdle (e.g. olive powder) to inactivate B. cereus spores has been investigated (Aoyama et al, 2005;Arroyo et al, 1997;Evelyn and Silva, 2015b;Fornari et al, 1995;Gola et al, 1996;Ju et al, 2008;Lopez-Pedemonte et al, 2003;Luu-Thi et al, 2014;Marco et al, 2011;McClements et al, 2001;Meyer, 2000;Raso et al, 1998;Robertson et al, 2008;Rovere et al, 1998;Scurrah et al, 2006;Shearer et al, 2000;Shigeta et al, 2007;van Opstal et al, 2004). B. cereus spore log reductions between 1 and ≥ 7 were achieved, depending on the conditions applied and the spore resistance.…”

“…Among these results, and Luu-Thi et al (2014) cereus spores in milk and cheese however the kinetics was not modeled. We have previously modeled the inactivation of psychrotolerant B. cereus spores in milk by HPP-thermal and found that the Weibull model appropriately described survival curves (Evelyn and Silva, 2015b). This bacterium presents high variability in the spore resistance and is able to grow in minced beef stored under refrigeration.…”