Microbiological Analysis of Marjoram Leaves

The marjoram leaves were subjected to microbiological tests on the first and the fifth days after the plants were treated with ozone. The enumeration of Lactobacillus spp. in the raw material was determined using the method specified in PN-ISO 15214:2002 “Microbiology of food and animal feeding stuffs—Horizontal method for the enumeration of mesophilic lactic acid bacteria—Colony-count technique at 30 °C”. In accordance with this method, the count of living mesophilic lactic acid bacteria is performed in a solid MRS medium incubated at a temperature of 30 °C for 72 h. The yeast and mould count in 1 g of marjoram was determined using the method described in PN-EN ISO 21527-1:2009 “Microbiology of food and animal feeding stuffs—Horizontal method for the enumeration of yeasts and moulds. Colony count technique at 25 °C.” Enumeration of mesophilic aerobic bacteria in the relevant raw material was performed using the plate count method, in accordance with the standard set forth in (Ae) (O) PB-77/LM, 4th edition dated 07.12.2015. Finally, the presence of endospore producing anaerobes was determined using the method described in (Ae) (O) PB-13/LM, 4th edition, dated 07.04.2014. The analyses were performed in 3 replications.