Faculty of Food Technology and Biotechnology, University of Zagreb
Abstract
In Europe there is an increasing emphasis on the quality control of honey, especially on maximum limits of veterinary drug residues (particularly antibiotics) permitted in it. Streptomycin is an aminoglycoside antibiotic used in apiculture to protect bees against a variety of brood diseases. Romanian authorities have included it in the National Monitoring Program for honey manufacturers. In this study, an enzyme-linked immunosorbent assay (ELISA) screening test was validated as a detection method of streptomycin residues in honey. The ELISA experimental results were compared to those obtained by using an HPLC method. The values generated by the two methods were very close to each other. This fact certifies that ELISA method can be successfully used for quantitative detection of the amount of streptomycin in honey samples. Following validation, three types of honey (polyfloral, lime and acacia) were analyzed for streptomycin content after exposure to 4, 22, 30, 40 or 70 °C for 20 weeks. The results show that streptomycin mass fraction decreased with time and with the increase of temperature in all honey samples. The data collected were used to fit a second-order multiple linear regression model for predicting the degradation of streptomycin in honey samples as a function of temperature and storage period. Values of the calculated statistical indicators confirm a good predictive capability of mathematical and statistical models.U Europi se sve više provodi kontrola kvalitete meda, posebice maksimalno dozvoljenih količina ostataka veterinarskih lijekova (prvenstveno antibiotika). Streptomicin je aminoglikozidni antibiotik što se koristi u pčelarstvu, ponajviše za sprečavanje raznih bolesti legla. Rumunjske su vlasti nadzor tog antibiotika uvrstile u nacionalni program motrenja proizvedenog meda. U ovom je istraživanju validirana metoda detekcije ostataka streptomicina u medu pomoću ELISA testa, pri čemu su dobiveni rezultati uspoređeni s onima dobivenim HPLC metodom. Rezultati tih dviju metoda nisu se bitno razlikovali, čime je dokazano da se ELISA test može uspješno primijeniti za određivanje količine streptomicina u uzorcima meda. Nakon validacije ispitana su tri tipa meda (poliflorni, med lipe i bagremov med), te je određen maseni udjel streptomicina u uzorcima nakon 20 tjedana skladištenja pri 4, 22, 30, 40 i 70 ºC. Rezultati pokazuju da se s porastom temperature udjel streptomicina u svim uzorcima meda tijekom vremena smanjio. Pomoću dobivenih podataka napravljen je model višestruke linearne regresije drugoga reda za procjenu razgradnje streptomicina u uzorcima meda tijekom skladištenja pri različitim temperaturama. Dobivene su vrijednosti potvrdile da se primjenom matematičkih i statističkih modela može predvidjeti razgradnja streptomicina u medu
