Microbial quality and antibacterial effect of honey

Med pripada skupini visoko vrijednih namirnica koje su poznate od davnina. U najvećoj mjeri je sastavljen od ugljikohidrata (od kojih je fruktoze i glukoze od 85 – 95 %) i ostalih spojeva poput organskih kiselina, aminokiselina, proteina, minerala, vitamina i lipida. Kvaliteta med procjenjuje se na osnovi senzorskih, kemijskih, fizikalnih i mikrobioloških svojstava. Svrha ovog rada je ispitati mikrobiološka svojstva 72 uzorka meda i odrediti prisutnost aerobnih mezofilnih i sporogenih bakterija, plijesni i kvasaca, sulfitoreducirajućih klostridija, bakterija porodice Enterobacteriaceae i bakterije vrste Staphylococcus aureus. Svi uzorci meda zadovoljili su mikrobiološke uvjete kvalitete, dok prisutnost patogenih bakterija nije detektirana. Ispitan je i inhibitorni potencijal uzoraka meda u sljedećim koncentracijama (0,1 %, 5 %, 10 %, 25 %, 50 % i 75 %). Najsnažnija inhibicija prema odabranim bakterijama primijećena je pri koncentraciji meda od 75 %. Med medljikovac i med kestena su pokazali najsnažniji inhibitorni učinak, a med lipe najslabiji. Unutar iste vrste meda utvrđena su značajna odstupanja u inhibitornom potencijalu. Najosjetljivija bakterija na inhibitorni učinak meda je Staphylococcus aureus, dok je najotpornija vrsta Enterococcus faecalis.Honey is one of highly nutritive value food known from ancient times. It is mainly composed of carbohydrates (of which fructose and glucose for nearly 85 – 95 %) and other minor substances, such as organic acids, amino acids, proteins, minerals vitamins and lipids. The quality of honey is mainly determined by its sensorial, chemical, physical and microbiological properties. The main purpose of this research was to evaluate microbiological properties of 72 honey samples and to evaluate number and/or presence of aerobic mesophilic and sporogenic bacteria, moulds and yeasts, sulphite-reducing clostridia, family of Enterobacteriaceae and specie of Staphylococcus aureus. Microbiological quality of all samples was considered good and all samples showed to be negative in respect to safety parameters. Inhibitory potential of selected honey samples was also investigated. Of tested honey concentrations (0,1 %, 5 %, 10 %, 25 %, 50 % i 75 %), final concentration of 75 % was the most potent. Honeydew and chestnut honey exhibited the most potent inhibitory effect to tested bacterial species, while the lowest inhibition exhibited lime (linden) honey. Among the same honey specie, considerable different inhibitory activity can be detected. The most sensitive bacterial specie was Staphylococcus aureus while the most resistant one was Enterococcus faecalis