title: Effect of heating rate on highly heat-resistant spore-forming microorganisms.
abstract: Highly heat-resistant spore-forming Bacillus cause nonsterility problems in canned food and reduce the shelf life of many processed foods. The aim of this research was to evaluate the thermal inactivation of Bacillus sporothermodurans IIC65, Bacillus subtilis IC9, and Geobacillus stearothermophilus T26 under isothermal and nonisothermal conditions. The data obtained showed that B. sporothermodurans and B. subtilis were more heat resistant than G. stearothermophilus. The survival curves of B. sporothermodurans and B. subtilis showed shoulders, while the survival curves of G. stearothermophilus showed tails. Under nonisothermal treatment, at heating rates of 1 and 20 ℃/min, time needed to completely inactivate G. stearothermophilus was shorter than that required for B. sporothermodurans and B. subtilis. In complex heat treatments (heating-holding-cooling), the survival curves of B. sporothermodurans and B. subtilis showed the same activation shoulders than those obtained under isothermal treatments and the activation shoulders were again absent in the case of G. stearothermophilus. Predictions fitted quite well the data obtained for B. sporothermodurans. In contrast, the data for B. subtilis showed half a log cycle more survival than expected and in the case of G. stearothermophilus, the survival curve obtained showed much higher inactivation than expected.
authors: Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain.
authors: Isabel
authors: I
authors: Gómez-Jódar
authors: Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain.
authors: María
authors: M
authors: Ros-Chumillas
authors: Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain alfredo.palop@upct.es.
authors: Alfredo
authors: A
authors: Palop
mesh_terms: D001407:Bacillus / Q000145:classification / Q000254:growth & development; D001412:Bacillus subtilis / Q000254:growth & development; D005506:Food Contamination; D005516:Food Microbiology; D057141:Food, Preserved / Q000382:microbiology*; D001411:Geobacillus stearothermophilus / Q000254:growth & development; D006358:Hot Temperature; D050296:Microbial Viability; D013171:Spores, Bacterial / Q000502:physiology*
keywords: Bacillus sporothermodurans; Bacillus subtilis; Geobacillus stearothermophilus; heat resistance; inactivation kinetics; spores