Selected methods of microbiological quality assessment of lime and acacia honeys available on Polish market

Abstract

In mature honeys small quantities of microorganisms are detected, thus the objective of this research study was to identify the most effective method to microbiologically assess this product. The analyses were carried out using three methods: classical surface, pour plate and spiral culture. Two varietal honey samples were used in the analyses: acacia honey and lime honey. The scope of the research study included the microbiological analyses targeted at the determination of total number of mesophilic aerobic microorganisms, yeast and mould, and mesophilic spore-forming bacteria Bacillus spp. Moreover, the following was determined: pH value, water content and water activity. As for the lime honey, the results of the analyses performed using the three above named methods did not differ statistically significantly as regards the total number of mesophilic aerobic microorganisms and spore-forming bacteria Bacillus spp. However as for the acacia honey, the total number of mesophilic aerobic microorganisms was statistically significantly higher when obtained using the spiral culturing method of analysis and the count of spore-forming bacteria Bacillus spp. – when obtained using the pour plate method. In all the tested samples of acacia honey and the two samples of lime honey (S7 and S5), the count of spore-forming bacteria Bacillus spp. exceeded the limit of 5 × 102 cfu/g. In the case of yeast and mould analyses, the results of the analysis obtained by the pour plate method were statistically significantly higher than those obtained using other two methods. In none of the analysed samples of acacia and lime honey, the limit of 5 × 102 cfu/g of the product was exceeded. Based on the analyses performed, it can be concluded that TCAM can be performed using any method, but the pour plate method is recommended for use to analyse yeast and mould and spore-forming bacteria Bacillus spp.