Heat resistance of five spoilage microorganisms in a carbonated broth

• Published in: Food microbiology 2024-09, Vol.122, p.104545-104545, Article 104545
• Main Authors: Saubade, Fabien, Cossec, Noëmie, Giguelay Gesret, Luc, Kouamé, Christelle, Ellouze, Mariem, Gérard, Cédric, Couvert, Olivier, Desriac, Noémie
• Format: Article
• Language: English
• Subjects: Alicyclobacillus - growth & development; Alicyclobacillus - physiology; Aspergillus niger - growth & development; Beverage; Byssochlamys - growth & development; Carbon Dioxide - metabolism; Carbonated Beverages - microbiology; Carbonation; Culture Media - chemistry; Culture Media - metabolism; Food Contamination - analysis; Food Contamination - prevention & control; Food Microbiology; Hot Temperature; Hydrogen-Ion Concentration; Modified atmosphere; Predictive microbiology; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - physiology; Spoilage; Thermal treatment; Zygosaccharomyces - growth & development; Zygosaccharomyces - physiology
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2024.104545

Despite their acidic pH, carbonated beverages can be contaminated by spoilage microorganisms. Thermal treatments, before and/or after carbonation, are usually applied to prevent the growth of these microorganisms. However, the impact of CO2 on the heat resistance of spoilage microorganisms has never been studied. A better understanding of the combined impact of CO2 and pH on the heat resistance of spoilage microorganisms commonly found in carbonated beverages might allow to optimize thermal treatment. Five microorganisms were selected for this study: Alicyclobacillus acidoterrestris (spores), Aspergillus niger (spores), Byssochlamys fulva (spores), Saccharomyces cerevisiae (vegetative cells), and Zygosaccharomyces parabailii (vegetative cells). A method was developed to assess the impact of heat treatments in carbonated media on microbial resistance. The heat resistances of the five studied species are coherent with the literature, when data were available. However, neither the dissolved CO2 concentration (from 0 to 7 g/L), nor the pH (from 2.8 to 4.1) have an impact on the heat resistance of the selected microorganisms, except for As. niger, for which the presence of dissolved CO2 reduced the heat resistance. This study improved our knowledge about the heat resistance of some spoilage microorganisms in presence of CO2. •A new method was developed to assess the impact of CO2 on heat resistance.•Only thermal resistance of Aspergillus niger is affected by CO2 addition.•No impact of pH (between pH 2.8 and 4.1) on heat resistance was observed.