Differentiating between Monofloral Portuguese Bee Pollens Using Phenolic and Volatile Profiles and Their Impact on Bioactive Properties.

Nowadays, bee products are commended by consumers for their medicinal and dietary properties. This study aimed to differentiate between monofloral bee pollens originating from Portugal using phenolic and volatile profiles and investigate their antioxidant and cytotoxic activity. Total phenolic and flavonoid compounds were recorded between 2.9-35.8 mg GAE/g and 0.7-4.8 mg QE/g, respectively. The LC/DAD/ESI-MSn analytical results allowed us to identify and quantify a total of 72 compounds, including phenolic and phenylamide compounds, whereas GC-MS results revealed the presence of 49 different compounds, mostly ketones, aldehydes, esters, hydrocarbons, and terpenes. The highest DPPH• radical scavenging activity, EC50: 0.07 mg/mL, was recorded in the sample dominated by Castanae sp. pollen, whereas the Rubus sp. (1.59 mM Trolox/mg) and Cistaceae sp. (0.09 mg GAE/g) pollen species exhibited the highest antioxidant activity in ABTS•+ and reducing power assays, respectively. Regarding the anti-carcinogenic activity, only Carduus sp. showed remarkable cytotoxic potential against MCF-7.

Evaluation of Antioxidant and Anticancer Activity of Mono- and Polyfloral Moroccan Bee Pollen by Characterizing Phenolic and Volatile Compounds.

Bee pollen is frequently characterized as a natural source of bioactive components, such as phenolic compounds, which are responsible for its pharmaceutical potential and nutritional properties. In this study, we evaluated the bioactive compound contents of mono- and polyfloral bee pollen samples using spectroscopic and chromatographic methods and established links with their antioxidant and antitumor activity. The findings demonstrated that the botanical origin of bee pollen has a remarkable impact on its phenolic (3-17 mg GAE/g) and flavonoid (0.5-3.2 mg QE/g) contents. Liquid chromatography-mass spectrometry analysis revealed the presence of 35 phenolic and 13 phenylamide compounds in bee pollen, while gas chromatography-mass spectrometry showed its richness in volatiles, such as hydrocarbons, fatty acids, alcohols, ketones, etc. The concentration of bioactive compounds in each sample resulted in a substantial distinction in their antioxidant activity, DPPH (EC50: 0.3-0.7 mg/mL), ABTS (0.8-1.3 mM Trolox/mg), and reducing power (0.03-0.05 mg GAE/g), with the most bioactive pollens being the monofloral samples from Olea europaea and Ononis spinosa. Complementarily, some samples revealed a moderate effect on cervical carcinoma (GI50: 495 µg/mL) and breast adenocarcinoma (GI50: 734 µg/mL) cell lines. This may be associated with compounds such as quercetin-O-diglucoside and kaempferol-3-O-rhamnoside, which are present in pollens from Olea europaea and Coriandrum, respectively. Overall, the results highlighted the potentiality of bee pollen to serve health-promoting formulations in the future.

Variability of kinetic parameters due to biomass acclimation: case of para-nitrophenol biodegradation.

The study regards para-nitrophenol (p-NP) removal by a mixed culture in a batch reactor under aerobic conditions performed at low ratio substrate (p-NP) to p-NP degrading microorganisms (0.09 < I(0)/(X(B,PNP))(0) < 0.80 g COD(PNP)g VSS(-1)). p-NP biodegradation was modelled with a dual-biomass kinetic including Haldane formalism. The purpose was to examine the effect of operating conditions of acclimation phases in the kinetic parameters estimated by respirometric measurements. The experiments were conducted with a series of successive additions of p-NP and a biogenic substrate (Ss) in different proportions (0 < R = Ss/I < 6.6). To place emphasis on decisive role played by frequency and amount of p-NP supply, a parallel was drawn with continuous processes, characterising acclimation cycles by different organic loading rate (207 < OLR < 1490 mg COD(PNP) l(-1) d(-1)). During acclimation, results showed progressively decreasing half saturation constant (K(s)(PNP)) values (11.4-1.21 mg CODl(-1)) whereas inhibition coefficient K(I)(PNP) increased (72.4-289 mg CODl(-1)), as the specific degradation rate increased. The inverse behaviour was observed during starvation periods. At the end of acclimation, higher values of growth yield (0.39 < Y(PNP) < 0.63 mg COD(X) mg COD(PNP)(-1)) and maximum growth rate (1.09 < mu(max)(PNP) < 2.01 d(-1)) were obtained for cycles with low R.