Comparative study on the impact of equally stressful environmental sporulation conditions on thermal inactivation kinetics of B. subtilis spores

Freire, Víctor (Universidad de Zaragoza) ; Del Río, Javier ; Gómara, Paula (Universidad de Zaragoza) ; Salvador, Maika (Universidad de Zaragoza) ; Condón, Santiago (Universidad de Zaragoza) ; Gayán, Elisa (Universidad de Zaragoza)

Resumen: Control of bacterial spores continues to be one of the main challenges for the food industry due to their wide dissemination and extremely high resistance to processing methods. Furthermore, the large variability in heat resistance in spores that contaminate foods makes it difficult to establish general processing conditions. Such heterogeneity not only derives from inherent differences among species and strains, but also from differences in sporulation environments that are generally ignored in spores encountered in foods. We evaluated heat inactivation kinetics and the thermodependency of resistance parameters in B. subtilis 168 spores sporulated at adverse temperatures, water activity (aw), and pH, applying an experimental approach that allowed us to quantitatively compare the impact of each condition. Reduction of incubation temperature from the optimal temperature dramatically reduced thermal resistance, and it was the most influential factor, especially at the highest treatment temperatures. These spores were also more sensitive to chemicals presumably acting in the inner membrane. Reducing sporulation aw increased heat resistance, although the magnitude of that effect depended on the solute and the treatment temperature. Thus, changes in sporulation environments varied 3D100°C values up to 10.4-fold and z values up to 1.7-fold, highlighting the relevance of taking such a source of variability into account when setting heat processing conditions. UV-C treatment and sodium hypochlorite efficiently inactivated all spore populations, including heat-resistant ones produced at low aw.

Idioma: Inglés

DOI: 10.1016/j.ijfoodmicro.2023.110349

Año: 2023

Publicado en: INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY 405 (2023), 110349 [11 pp.]
ISSN: 0168-1605

Factor impacto JCR: 5.0 (2023)

Categ. JCR: MICROBIOLOGY rank: 29 / 161 = 0.18 (2023) - Q1 - T1
Categ. JCR: FOOD SCIENCE & TECHNOLOGY rank: 34 / 173 = 0.197 (2023) - Q1 - T1

Factor impacto SCIMAGO: 1.026 - Food Science (Q1) - Safety, Risk, Reliability and Quality (Q1) - Medicine (miscellaneous) (Q1) - Microbiology (Q2)

Financiación: info:eu-repo/grantAgreement/ES/MCIN/PID2019-104712GB-I00

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Tecnología de Alimentos (Dpto. Produc.Animal Cienc.Ali.)