Enumeration and Identification of Bacterial Spores in Cocoa Powders
| Autor: | Henri Kamphuis, Michiel Kokken, Rosanne de Groot, Angelina Kuijpers, Geertje van de Rijdt, Marjon H. J. Wells-Bennik, Franziska Breitenwieser, Erik Hoornstra, CÉcile Vadier, IndauÊ Ieda Giriboni de Mello, Robyn T. Eijlander |
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| Rok vydání: | 2020 |
| Předmět: |
Hot Temperature
food.ingredient Food spoilage Colony Count Microbial Bacillus Microbiology Endospore 03 medical and health sciences food Animals Agar Food microbiology Bacillus licheniformis Food science Chocolate 030304 developmental biology Spores Bacterial 0303 health sciences biology 030306 microbiology Chemistry fungi food and beverages COCOA BEAN biology.organism_classification food.food Spore Milk Fermentation Powders Food Science |
| Zdroj: | Journal of Food Protection. 83:1530-1540 |
| ISSN: | 0362-028X |
| DOI: | 10.4315/jfp-20-071 |
| Popis: | The presence of bacterial spores in cocoa powders is inevitable due to the cocoa bean fermentation process, during which members of the genera Bacillus and Geobacillus are typically present. Spores are a concern in heat-treated foods when they survive heat treatments and the finished product supports germination, growth, and potentially toxin production. In this study, available methods for the enumeration of total mesophilic and thermophilic spores (TMS and TTS, respectively) were evaluated, leading to the recommendation of one global method specifically for cocoa powders. The proposed method was validated during a ring test on seven selected cocoa powders and applied during routine analyses on commercial powders. The method includes dilution of cocoa powder using buffered peptone water, heating at 80°C for 10 min for TMS and TTS counts, and heating at 100°C for 30 min for a heat-resistant (HR) spore count. Tryptic soy agar is used as a recovery medium with a maximal concentration of cocoa powder of 2.5 mg/mL (to prevent growth inhibition) and a nonnutrient agar overlay to prevent swarming of bacteria. Plates are incubated for at least 72 h at 30°C for recovery of mesophilic bacteria and 55°C for thermophilic bacteria. Suitable alternatives to specific method parameters are provided. Median values of total spore concentrations are low ( |
| Databáze: | OpenAIRE |
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