Effects of Pollen Feeding on Quality of Royal Jelly.

This study was carried out to assess the impact of pollen feeding from common floral sources in Thailand (e.g., tea, coffee, and bitter bush) on royal jelly (RJ) properties (i.e., protein pattern, (E)-9-hydroxydec-2-enoic acid (9-HDA), and (E)-10-hydroxy-2-decenoic acid (10-HDA) contents and antibacterial activity). The protein patterns from three different pollen were different, while RJ samples derived from bee colonies fed by different pollen, exhibited similar protein patterns. RJ samples from bee colonies fed by pollen from bitter bush and coffee possessed the higher 10-HDA levels than RJ collected from bee colonies fed by tea pollen. The 9-HDA was found in lower amount than 10-HDA in every sample. Even though the antibacterial activities of pollen were varied, however, RJ samples exhibited similar antibacterial properties. This is the first report showing that different pollen feeding affected 10-HDA contents, but not affected overall protein content and antibacterial properties.

Volatile organic compounds of Thai honeys produced from several floral sources by different honey bee species.

The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin. Interestingly, 2-phenylacetaldehyde was detected in all honey sample except longan honey produced by A. cerana. Thirty-two VOCs were identified as possible floral markers. After validating differences in honey volatiles from different floral sources and honeybee species, the results suggest that differences in quality and quantity of honey volatiles are influenced by both floral source and honeybee species. The group of honey volatiles detected from A. cerana was completely different from those of A. mellifera and A. dorsata. VOCs could therefore be applied as chemical markers of honeys and may reflect preferences of shared floral sources amongst different honeybee species.