Assessing monofloral bee pollens from Türkiye: Palynological verification, phenolic profile, and antioxidant activity

Abstract

Abstract: Honey bee pollen (HBP) is a hive product produced by worker bees from floral pollen grains agglutination. It is characterized by its excellent nutritional and bioactive composition, making it a superior source of human nutrition. This study aimed to evaluate the monofloral bee pollen samples, including Cistus, Crataegus monogyna, Cyanus, Elaeagnus angustifolia, Papaver somniferum, Quercus, Salix, Sinapis, and Silybum from Türkiye according to palynological analysis, antioxidant activity, phenolic profiles, and color. The phenolic profiles were detected using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Bee pollens were categorized into monofloral, bifloral, and multifloral, underscoring the significance of confirming the botanical source of them depending on palynological analyses. Total phenolic content (TPC) of bee pollens ranged from 4.5 to 14.4 mg gallic acid/g HBP. The samples exhibited antioxidant activity for 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS •+) ranging from 94.9 to 233.5 µmol trolox/g HBP, whereas lower values were seen for 2,2-diphenyl-1-picrylhydrazyl (DPPH•) ranging from 25.86 to 70.81 µmol trolox/g HBP. A yellowish-red tint color was also displayed for whole samples, whereas only E. angustifolia bee pollen indicated a darker color (L* = 31.6). Among the phenolic compounds, luteolin, kaempferol, isorhamnetin, rutin, and genistein were the most abundant, and their profiles varied across the samples. It was also observed that TPC, antioxidant activities, and polyphenol composition were higher in samples containing pollen grains of P. somniferum, Quercus, Plantago, and E. angustifolia species. Practical Application: The increasing number of new findings on honey bee pollen is crucial to food science and technology. In this sense, this study offers a robust method for verifying the authenticity and quality of 11 monofloral bee pollens, which is crucial for the food industry. It also identifies potential sources of high-quality pollen, benefiting producers, and consumers seeking superior bee pollen products.