Microbial modeling of thermal resistance of Alicyclobacillus acidoterrestris CRA7152 spores in concentrated orange juice with nisin addition

Abstract

The nisin effect on thermal death of Alicyclobacillus acidoterrestris CRA 7152 spores in concentrated orange juice (64°Brix) was studied. Concentrations of 0, 50, 75 and 100 IU of nisin/ml juice, at

Modeling the effects of temperature and pH on the resistance of Alicyclobacillus acidoterrestris in conventional heat-treated fruit beverages through a meta-analysis approach

“…Yet, our model still confirmed that the bacteriocins, nisin and bovicin, were bactericidal against Alicyclobacillus, as the D-values e hence, the viable cell numbers e decreased in their presence. Although there is evidence that higher doses of bacteriocins have greater effect on increasing the lethality of Alicyclobacillus spores (Peña et al, 2009;Komitopoulou et al, 1999), this was not assessed in this meta-analysis study.…”

“…However, as the main objective of such a study was to assess the effect of bovicin on the resistance of Alicyclobacilus in mango pulp, a logical conclusion was that the mango pulp, which was two-fold diluted for their experiments (i.e., concentrate), was not clarified. The fourth study characteristic was "presence of bacteriocins", which was conceived because two of the primary studies investigated the effect of nisin (Komitopoulou et al, 1999;Peña et al, 2009) on the thermal resistance of Alicyclobacillus; and one study the effect of bovicin HC5 e a bacteriocin from Streptococcus bovis (de Carvalho et al, 2008). Thus, this categorical variable was coded to take up the value of 0 for absence of bacteriocins and the value of 1 for added bacteriocins.…”

“…Thus, this categorical variable was coded to take up the value of 0 for absence of bacteriocins and the value of 1 for added bacteriocins. While de Carvalho et al (2008) employed a concentration of bovicin HC5 of 80 IU/ml in mango concentrate, Komitopoulou et al (1999) and Peña et al (2009) assessed both a concentration of 50 IU/ml in apple and orange juice, respectively.…”

“…Also, as a major target for fruit juice pasteurization (Tribst et al, 2009), numerous studies are found that report thermal inactivation parameters of Alicyclobacillus, i.e., the D value (time at a determined temperature required to cause one-log cycle decrease in the population of a target bacterium) and the z value (temperature increase required to result in one-log cycle decrease of Dvalue) (Splittstoesser et al, 1994;Komitopoulou et al, 1999;Bahçeci and Acar, 2007;Walls, 1997;Silva et al, 1999;Maldonado et al, 2008;de Carvalho et al, 2008;L opez et al, 2011;Alberice et al, 2012, Peña et al, 2009McKnight et al, 2010). As known, D-and z-values of Alicyclobacillus are affected by the particular conditions or study characteristics (protocols, fruit and variety, Brix, pH, temperature, heating medium, culture medium, inactivation method, strains, etc.)…”

Influence of Different Filling, Cooling, and Storage Conditions on the Growth of Alicyclobacillus acidoterrestris CRA7152 in Orange Juice

“…This is due to the extended time that the product is maintained at temperature conditions adequate for the germination and outgrowth of acidothermophilic spore-forming microbes. Despite several studies regarding the factors that affect A. acidoterrestris growth and heat resistance (12,18,2,29), there is a lack of research on the effects of hot-filled fruit juice storage conditions on A. acidoterrestris growth during juice storage. Thus, this study aimed at estimating and comparing the growth parameters (maximum population ratio, ; lag time, ; and maximum growth rate, ) of A. acidoterrestris survival in hot-filled orange juice that was cooled and stored under several conditions that simulate industrial and commercial practices.…”