Peel Plate Microbial Tests

Total Coliform Peel Plate CC selective media encourages the growth of coliform bacteria. The presence of coliform is an indicator of unsanitary conditions in raw products. Coliform are killed by effective heat steps in food processing. Coliform appear as red colonies within 24 hours at 32 or 35°C. Coliforms are closely regulated in dairy and some foods the US and Peel Plate Coliform tests are listed in the PMO.

The Enterobacteriaceae bacteria are a family of gram negative bacteria encompassing coliform, E. coli, Shigella, Salmonella, and Yersinia. These bacteria indicate unsanitary conditions in raw products and are killed by heat steps in food processing. EB testing is used as a post-production verification of process and pathogen risk used, for example, to test dry milk powder and infant formula. EB is regulated globally, similar to coliform/E.coli regulation in the US. Incubation 24 to 48 hours at 37°C produce multiple colored round growth spots that are all recorded as EB. High Volume plates are available.

Visit the Peel Plate EB test page to learn more.

Generic E.coli, considered a fecal risk indicator, is a subset of coliform and are differentiated with the Peel Plate EC formulation. Peel Plate EC are AOAC-RI validated for a number of dairy products, meat rinses, water testing, and environmental sampling. Coliform appear as round red colonies and E. coli as round blue colonies within 24 hours at 35°C and the sum of red and blue are total coliform.

Heterotrophs are aerobic bacteria that are more associated with water and nutrient-depleted matrices. Peel Plate HET nutrient-depleted media encourages the growth of heterotrophic organisms in water. Incubation at 20 to 28°C produces red growth spots within 5 to 7 days. Heterotrophs are used as indicators to assess biofilm build-up, and nutrient leaching in water distribution systems of food plants and water municipalities.

Staphylococcus aureus can be present in eggs, meat, poultry, milk, and dairy products and are spread through hand contact with environmental surfaces or hand-prepared food items. Peel Plate SA tests are used to test finished products and environmental samples.

S. aureus bacteria appear within 24 hours, with an additional 24 hours for presumptive positive confirmation (48 hours total) at 35 to 37°C. Tests with no growth at 24 hours are considered negative for S. aureus.

Visit the Peel Plate SA test page to learn more.

Peel Plate selective media with antibiotic prevents the growth of bacteria, and encourages the growth of fungi. Fungi organisms are primarily a food spoilage risk but can also produce toxins. Peel Plate YM are AOAC-RI validated for a variety of dairy products, fresh fruits and vegetables, juices, RTE foods, and environmental surfaces. Incubation 3 to 5 days at 25ºC produce green/blue growth spots. High Volume plates are available.