THE EFFECT OF STORAGE TIME ON THE ANTIOXIDANT ACTIVITY AND POLYPHENOLIC PROFILE OF FROZEN AND LYOPHILIZED DRONE BROOD FIXED IN HONEY

Abstract

Background. The purpose of the study was to evaluate the effect of drone brood fixation in rape honey and to analyze changes in its antioxidant activity during storage. The fixation was carried out for frozen and lyophilized drone brood, which were mixed with honey in various proportions (1, 2, and 4 % w/w). The antioxidant activity (DPPH and FRAP methods) and the total content of polyphenolic compounds (TPC) after 3, 6, and 9 months of storage were analyzed. After 9 months of storage, the polyphenolic profile (HPTLC method) and physicochemical parameters of samples were assessed. Results and conclusion. The addition of drone brood to honey increased the antioxidant activity of the final product considerably (by 33 to 110 %), while only slightly affected the physicochemical parameters (conductivity and a diastase number) compared to control honey. Moreover, honey with the addition of drone brood still continued to meet the requirements for honey standard. The polyphenol profile obtained by HPTLC method for honey with the addition of drone brood was enriched mainly with ellagic and ferulic acids compared to control honey. It was found that fixing the drone brood in honey allows to maintain its antioxidant properties for 6 months, whereas a significant decrease in reducing power (FRAP) and polyphenolic content (TPC) during prolonged storage were observed (from 8 to 26 % ). Due to the fact that lower losses were observed for the addition of frozen than for lyophilized drone brood after 9 months of storage, preserving the frozen brood in honey (up to 5 % w/w) can be recommended as an effective and inexpensive method available in apiary conditions.