Assessment of the Antimicrobial Effect of Honey, Treated By Heat and Ultraviolet Radiation

Abstract

Honey bees are the main product being widely used by humans as food and as medicine. Honey is widely usedin food, being highly appreciated in the traditional medicine. It also has important applications in natural feedingand pre-post-operative treatments in pediatric, dermatology and gastrology. In this paper we aimed to test theantibacterial effect of some types of honey treated by heat and ultraviolet radiation (UV).For the experiment we used four types of honey (polyo€loral, lime, acacia and suno€lower) harvested from Salajcounty. The antibacterial effect was tested on 11 strains of Staphylococcus spp., one stain of Staphylococcus aureusATCC 6538P, Bacillus cereus strain ATCC 14579, Escherichia coli ATCC 10536 one, and a Pseudomonas aeruginosaATCC 27853. After the heat treatment, test method was represented by the diffusion of the samples according tothe CLSI (2011), adapted to the product. The antimicrobial effect of honey treated with UV was achieved by mixinghoney and maintenance of microbial strains to UV for 1 hour and then determining the number of live bacteriaexpressed in colony forming units (CFU). For both test and control, samples were used without heat treatmentor by UV and the results compared to the control. Tests to identify chemical compounds that degrade after thesetreatments were also performed.After the examination of the results, it was observed that at 70 and 1000C honey treatment reduced theantimicrobial effect of honey with about half on most microbial strains. It was also found that temperatures of70 and 1000C affect differently depending on the type of honey and tested strain. Temperature of 37 and 500Cdoes not diminish the antibacterial effect of honey. The chemical analyzes revealed an increase of HMF’s highheat treatment. UV-decreased the amount of HMF in honey diastase index decreasing after heat treatment andincreasing following treatment with ultraviolet (UV) radiation, while the carbohydrates in honey have undergonesignio€icant changes after heat and ultraviolet treatment.The experiment offers some interesting new data on theeffect of two types of treatments in order to obtain honey types with standardized parameters.