Chemical and cytological evaluation of honeybee pollen antioxidant ability

"Plant Golden" C. sativus: Qualitative and quantitative analysis of major components in stigmas and petals and their biological activity in vitro

Crocus sativus L. (C. sativus) has its stigma as the main valuable part used. With extremely low production and high prices, stigma is considered a scarce resource. As a result, its petals, considered as by-products, are often discarded, leading to significant waste. We developed a UPLC-Q-Orbitrap HRMS method for qualitative analysis of stigmas and petals and a UHPLC-QQQ-MS/MS method for simultaneous quantification of 9 characteristic active compounds for the first time, and compared their biological activity in vitro. The results indicated that a total of 63 compounds were identified in the petals and stigmas. The content of flavonoids in the petals was significantly superior to that in the stigma, and the content of quercetin in the petals was 50 times higher than that in the stigma. The results of the in vitro evaluation of biological activity indicated that both the petals （•OH: IC50=39.70 mg/mL; DPPH: IC50=28.37 mg/mL; ABTS: IC50=0.9868 mg/mL）and stigma （•OH: IC50=34.41 mg/mL; DPPH: IC50=38.99 mg/mL; ABTS: IC50=3.194 mg/mL）demonstrated comparable antioxidant activities. However, the tyrosinase inhibitory activity in petals （IC50=21.17 mg/mL） was weaker than that in stigma（IC50=1.488 mg/mL）. This study provides a fast, reliable, and efficient analytical method that can be used for the quality assessment of petals as a natural resource and its related products in the food and pharmaceutical industries.

Innovative multiple nanoemulsion (W/O/W) based on Chilean honeybee pollen improves their permeability, antioxidant and antibacterial activity

Beehive derivatives, including honeybee pollen (HBP), have been extensively studied for their beneficial health properties and potential therapeutic use. Its high polyphenol content gives it excellent antioxidant and antibacterial properties. Today its use is limited due to poor organoleptic properties, low solubility, stability, and permeability under physiological conditions. A novel edible multiple W/O/W nanoemulsion (BP-MNE) to encapsulate the HBP extract was designed and optimized to overcome these limitations. The new BP-MNE has a small size (∼100 nm), a zeta potential greater than +30 mV, and efficiently encapsulated phenolic compounds (∼82%). BP-MNE stability was measured under simulated physiological conditions and storage conditions (4 months); in both cases, stability was promoted. The formulation's antioxidant and antibacterial (Streptococcus pyogenes) activity was analyzed, obtaining a higher effect than the non-encapsulated compounds in both cases. In vitro permeability was tested, observing a high permeability of the phenolic compounds when they are nanoencapsulated. With these results, we propose our BP-MNE as an innovative solution to encapsulate complex matrices, such as HBP extract, as a platform to develop functional foods.

Chemical constituents and phytochemical properties of floral maize pollen

Currently, bee-gathered pollen (bee pollen) is commonly used worldwide as a dietary supplement and is recognized for its curative properties. Floral pollen is also important but is less recognized due to a lack of investigation. This study aims to determine the morphological characteristics and nutritional and phytochemical properties of floral maize pollen. Fresh pollen grains harvested from a farm of maize plants are yellow in colour and spheroid in shape. They change to amber and indented prismatic solid shapes when dehydrated. The main composition of floral maize pollen is carbohydrates (44.30±3.73%), followed by moisture (23.38±5.73%), crude proteins (17.16±3.13%), crude fibres (9.56±0.92%), and ash (4.98±0.11%), while the lowest content is observed for crude fats (0.62±0.06%). The predominant mineral is potassium (768.50±11.40 mg 100 g-1), followed by sodium (695.10±9.70 mg 100 g-1), calcium (147.20±12.60 mg 100 g-1), and magnesium (97.30±2.9 mg 100 g-1). The microelements (with average values) consist of iron (49.50±3.30 mg 100 g-1) and zinc (30.00±3.70 mg 100 g-1). Excellent phytochemical properties add value to floral maize pollen. Maize pollen contains a high total phenolic content (TPC) and total flavonoid content (TFC) of 783.02 mg GAE 100 g-1 and 1706.83 mg QE 100 g-1, respectively, and possesses strong antioxidant activity of 10.54 mg mL-1. Maize floral pollen and derived products can serve as future food resources for human consumption and as a source of functional and bioactive compounds in nutraceutical and pharmaceutical industries.