Thermal inactivation of Bacillus cereus spores affected by the solutes used to control water activity of the heating medium

Mazas, M.; Varela, Silvia; López, Mercedes; Álvarez, Ana Bernardo; Martin, Roberto

doi:10.1016/s0168-1605(99)00145-2

Cited by 46 publications

(29 citation statements)

References 26 publications

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“…The D-values recorded in the present study for three cultures of B. cereus were almost closer to those values reported earlier for the strain of B. cereus ATCC 4342 and 7004 when subjected to heat treatment in buffers of pH 7.0 and milk medium at 90°C (Montville et al 2005;Moussa-Boudjemma et al 2006) and 95°C (Mazas et al 1999a). In a study with spores of B. cereus ATCC 7004 (Mazas et al 1999b), the D-values recorded at 92 and 96°C in saline and milk medium were quite lower to those observed in this study. As B. anthracis was in the same cluster as that of B. cereus, a similarity was observed in an earlier study with spores of B. anthracis Sterne (Novak et al 2005), wherein the D-values recorded at 100°C in skim milk was almost near to those recorded in the present study.…”

Section: Resultssupporting

confidence: 90%

“…The wide variations observed in the thermal inactivation pattern of spores of B. cereus could be attributed to one or more of the following (1) characteristics of strains of B. cereus with environmentally induced resistance due to dipicolinic acid content, degree of hydration and mineral content (Marquis and Shin 1994;Palop et al 1996;Mazas et al 1999b;Melly et al 2002;Baweja et al 2008), (2) temperatures which have induced spore formation as well as other conditions prevailing during sporulation (Condon et al 1992;Baweja et al 2008) and (3) heterogeneity in the cluster of spores with respect to germination and/or survival (Byrne et al 2006).…”

Section: Resultsmentioning

confidence: 99%

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Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods

Desai

Varadaraj

2010

J Food Sci Technol

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This study was undertaken to evaluate the behaviour of vegetative cells and spores of four potent native toxigenic food isolates of Bacillus cereus as affected by selected time-temperature combinations used in processing of Indian traditional foods. The vegetative cells of B. cereus when subjected to sublethal heat treatments, individually, in different heating menstra showed a sigmoidal inactivation pattern, with D-values in the range of 3.45 min at 60°C to 10.6 min at 56°C in saline. Accordingly, the zvalues recorded across the heating menstra ranged from 9.3°C in culture broth to 24°C in whole milk. Similarly, the inactivation pattern for spores for the same isolates was curvilinear with D-values ranging from 4.4 min at 95°C in whole milk to 19.45 min at 85°C in saline. The z-values for spores ranged from 16.6°C in saline to 38.4°C in whole milk. The thermal inactivation pattern observed for vegetative cells and spores indicate that the death rate was not constant during the process of heat treatment.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods

Desai

Varadaraj

2010

J Food Sci Technol

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“…When NaCl was used as the solute, L. innocua was more heat resistant. Mazas et al (1999) and Stewart et al (2002) arrived at similar conclusions. Listeria spp.…”

Section: Physicochemical Stressessupporting

confidence: 60%

“…Data available in literature revealed that when a w decreases, a marked increase in microbial thermal resistance is often observed. Results also suggested that the heat resistance of bacteria depends both on strain and type of solute chosen (Mazas, Martinez, Lopez, Alvarez, & Martin, 1999;Coroller, Leguerinel, & Mafart, 2001). The pH of the heating media is also an important factor that influences the thermal microbial inactivation.…”

Section: Introductionmentioning

confidence: 96%

nfluences of physicochemical stresses on injury and inactivation behaviour of Listeria innocua

Miller

Ramos

Gil

et al. 2017

IJFS

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Many minimally processed foods depend on a combination of inhibitory factors to reduce the hazard of foodborne illness. Therefore, inactivation of Listeria innocua was studied according to a 2 4 factorial experiment designed to draw conclusions about temperature (52.5°C and 65.0°C), pH (4.5 and 7.5), water activity (aw=0.95 and 0.99) and solute type (NaCl and glycerol) effects. Three different recovery media were used to assess injured cells. Survival data were fitted with a Gompertz-based model and kinetic parameters (shoulder, maximum inactivation rate -kmax, and tail) were estimated. Results showed that shoulder was affected by temperature, pH and combined effects; kmax was influenced by all factors and their combinations; and tail was affected by aw, temperature and aw/pH combination. Results demonstrated the potential occurrence of microbial cross-protection survival techniques between the various stresses, e.g. heat and osmolarity. Indeed, this work clearly established that, to avoid hazards, Listeria inactivation must be evaluated with a maximum of environmental factors that undergo alterations. Only thus, appropriate food preservation treatments can be developed and consequently, the safety of food products can be assured.

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“…It is generally recognized that sucrose is the most protective depressor, while glucose, sodium chloride, and lithium chloride show a clearly lower influence or even an opposite effect. Glycerol shows an intermediate behavior (13,19,20,26,37). Interactions between the influences of water activity and heating temperature were often observed.…”

mentioning

confidence: 99%

Effect of Water Activities of Heating and Recovery Media on Apparent Heat Resistance of Bacillus cereus Spores

Coroller¹,

Leguérinel²,

Mafart³

2001

Appl Environ Microbiol

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Spores of Bacillus cereus were heated and recovered in order to investigate the effect of water activity of media on the estimated heat resistance (i.e., the D value) of spores. The water activity (ranging from 0.9 to 1) of the heating medium was first successively controlled with three solutes (glycerol, glucose, and sucrose), while the water activity of the recovery medium was kept near 1. Reciprocally, the water activity of the heating medium was then kept at 1, while the water activity of the recovery medium was controlled from 0.9 to 1 with the same depressors. Lastly, in a third set of experiments, the heating medium and the recovery medium were adjusted to the same activity. As expected, added depressors caused an increase of the heat resistance of spores with a greater efficiency of sucrose with respect to glycerol and glucose. In contrast, when solutes were added to the recovery medium, under an optimal water activity close to 0.98, a decrease of water activity caused a decrease in the estimated D values. This effect was more pronounced when sucrose was used as a depressor instead of glycerol or glucose. When the heating and the recovery media were adjusted to the same water activity, a balancing effect was observed between the protective influence of the solutes during heat treatment and their negative effect during the recovery of injured cells, so that the overall effect of water activity was reduced, with an optimal value near 0.96. The difference between the efficiency of depressors was also less pronounced. It may then be concluded that the overall protective effect of a decrease in water activity is generally overestimated.It has been recognized that the heat resistance of bacterial spores depends on the medium in which the spores are heated. The maximum thermostability of most microorganisms was found in the range of between 0.2 and 0.4 water activity (1,3,27,28,29). In typical ranges of water activities which are found in foodstuffs (a w Ͼ 0.8), the heat resistance of microorganisms generally increases at decreasing water activities. However, the apparent effect of the water activity of the medium on spores or vegetative cells is complicated by the specific effect of solutes which are used as depressors. It is generally agreed that the occurrence of such solutes in the medium reduces the heat resistance of microorganisms. This antagonism between the protective effect of an increase in water activity and the opposite specific effect of depressors can explain conflicting data from various authors.The influence of salt on the thermostability of microorganisms is disputed and depends on the heated type of microorganism. Some authors found no effect of the sodium chloride concentration on the heat resistance of bacteria (9,29,32,42). Others observed a reduced heat resistance of microorganisms at increasing salt concentrations (7,12,22,23). On the contrary, a protective effect of salt was found in several studies (6,14,26,35,38,39,40). Corry (14) deduced from his data that sodium chloride had a therm...

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Thermal inactivation of Bacillus cereus spores affected by the solutes used to control water activity of the heating medium

Cited by 46 publications

References 26 publications

Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods

Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods

nfluences of physicochemical stresses on injury and inactivation behaviour of Listeria innocua

Effect of Water Activities of Heating and Recovery Media on Apparent Heat Resistance of Bacillus cereus Spores

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