Maturation and stratification of antibacterial activity and total phenolic content of bee bread in honey comb cells

Abstract

Bee bread is processed pollen stored in honey comb. Pollen foragers unload pollen loads into the appropriate cells and hive bees further process it into bee bread. This results in a layered structure of the reserve, which is at the top covered with honey and a wax cap. The process of pollen collection and packing was monitored during chestnut (Castanea sativa Mill.) flowering and five frames of honey comb with stored bee bread were collected. We dissected the bee bread cells into bottom, middle and upper layers of bee bread and an additional top honey layer. Cells were sampled before covering with honey, after adding honey, and after aging of covered cells for four weeks. Samples were analyzed according to pollen type content, antibacterial activity and total phenolic content. Our results indicated that microbial activity and processing by honey bees were the major contributors to the antibacterial activity observed. Total phenolic content did not correlate with antibacterial activity and was the highest at the bottom of the honey comb cell. Honey bees establish a controlled microenvironment for bee bread fermentation and probably additionally stop microbe activity at the end of the process with feeding glands secretions.