Apini and Meliponini foraging activities influence the phenolic content of different types of Malaysian honey

Abstract

Malaysian honeys are produced by two main bee genera: Apis and Trigona. Each bee species has long been reported to exhibit unique foraging patterns and time, and it is very likely that bee foraging activities play a significant role in the phenolic composition of honeys. This work aims to justify the potential relationship between species-specific foraging activities and phenolic composition of honeys, to distinguish polyphenolic profiles and to identify possible floral markers in each type of Malaysian honey studied. Seventeen samples of Malaysian gelam, acacia, nenas, tualang, and kelulut honeys were analyzed using a high-performance liquid chromatography with diode array detector (HPLC-DAD). Total phenolic contents ranged from 1.92 to 14.84 mg/g of honey, in nenas and gelam honey, respectively. Fifteen phenolic compounds were identified, probably affected by the bee foraging preference. The highest number was seen in kelulut honey (Trigona spp.) while the lowest were in tualang honey (10 compounds, Apis dorsata). Apis cerana indica showed the highest phenolic acid and flavonoid contents (8.74 mg/g honey) compared to the other bee species, probably due to less selective floral preference, longer duration and early foraging time as well as small body size that influence their foraging activity. Similarity in two dominant polyphenols from polyhenolic profiles between acacia and tualang honeys (naringenin and ellagic acid), and between gelam and kelulut honeys (ellagic acid and benzoic acid) suggesting that the floral source of unifloral honey is an equally important food source for the analyzed multifloral honey, was confirmed by PCA analysis. This work assumes that competition between bee species for nectar and pollen might exist, affecting honey production and total polyphenolic content. From the results, some polyphenolic profiles could be regarded as possible floral markers of Malaysian unifloral honeys, with very consistent profiles observed in nenas honeys.