Lipid characterization of chestnut and willow honeybee-collected pollen: Impact of freeze-drying and microwave-assisted drying

Honeybee-collected pollen is gaining attention as functional food, `due to its high content of bioactive compounds, such as essential amino acids, antioxidants, vitamins and lipids. Traditional conservation methods include drying in a hot air chamber or freezing. These techniques influence the pollen organoleptic properties and its content of nutraceutical compounds. We analysed the lipid component of two honeybee-collected pollens, Castanea sativa and Salix alba. Chestnut pollen was characterized by a higher level of omega-6 fatty acids, while willow pollen showed a higher concentration of omega-3 fatty acids and carotenoids. Furthermore, two novel conservation methods, freeze-drying and microwave- assisted drying, were proposed and their impact on the pollen lipid profile was assessed. Only the microwave treatment showed a damaging action on antioxidant compounds (i.e. reduction of tocopherols). Overall, this research shed light on the lipid profile of honeybee-collected pollen, highlighting the nutraceutical importance of pollen as a source of omega-6 and omega-3 polyunsaturated fatty acids.