Raw Pollen Research Articles

Long-term Holocene warming trend in Southern China revealed by corrected pollen data

Holocene temperature changes and their forcings serve as pivotal references for current and future warming trends. However, significant discrepancies exist between proxy reconstructions and model simulations of Holocene temperature evolution. Pollen evidence, often central to these discrepancies, have been criticized for potentially reflecting human influence rather than pure temperature variations, complicating our understanding of Holocene temperature changes. Our study focuses on southern China, a region with pronounced discrepancies between models and proxies. We introduce and validate a novel methodology to isolate genuine temperature signals from pollen data. This approach employs an arboreal pollen-based temperature index and correct biases inherent in raw pollen data using the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model. Applying this method, we present a new winter/annual temperature record for the past 10,000 years based on two fossil pollen data from the Luoxiao Mountains. Simultaneously, we reconstruct the historical impact of human activities in the region. Our temperature records reveal a sustained warming trend during the Holocene, closely matching model-simulated mean annual temperatures (R = 0.97), and temperature reconstructions based on branched glycerol dialkyl glycerol tetraethers from regional terrestrial and marine archives. In contrast, uncorrected pollen data indicate a cooling trend during the late Holocene, coinciding with significant human impact since approximately 3 ka BP. Our analysis and regional comparison with existing temperature records indicate that such contrasting temperature trends stem from a human-induced cooling bias, particularly pronounced in uncorrected pollen data. We infer that the early to middle Holocene warming was due to various factors, while late Holocene warming was predominantly driven by local annual insolation changes. Our findings challenge previously widely identified late-Holocene cooling trends based on uncorrected pollen data, demonstrating that the correction of pollen data can effectively mitigate human-induced cooling biases in temperature reconstructions. This study confirms the accuracy of climate models in simulating a Holocene warming trend, both temporally and spatially, at least in southern China.

Investigating the longstanding mystery of stigma length differences between morphs of distylous plants.

Longer stigmas in short-styled morphs of distylous plants have been considered an adaptive characteristic that increases intermorph pollen deposition. The greater pollen deposition in short-styled stigmas may be a by-product of their longer length, making deposition effectiveness comparison between morphs unfeasible. Thus, investigating which morph has the relatively most efficient stigma (i.e., pollen deposition per unit length) can boost our understanding of the adaptive significance of longer stigmas. Here, we compared pollen deposition between morphs relative to stigma length and assessed whether short-styled stigmas are more, less, or equally effective in receiving pollen grains per unit length. We reviewed the literature to characterize the extent of sigma length differences between morphs using the two most speciose distylous genera as model systems: Palicourea and Psychotria (Rubiaceae). Then, we conducted a between-morph comparison of raw and relative pollen depositions in a Palicourea rigida population. We confirmed that short-styled stigmas were longer than long-styled stigmas in both Palicourea (194.31% longer) and Psychotria (52.59% longer) flowers. Furthermore, in the focal Pal. rigida, although short-styled stigmas were 268.04% longer and received 97.04% more pollen grains than long-styled stigmas, the relative pollen deposition had a reverse pattern, with short-styled stigmas being two-times less efficient in receiving pollen. Our results indicate that the longer length of the short-styled stigmas may have a compensatory effect, increasing the chances of pollen grains reaching the stigma and probably maintaining disassortative intermorph pollination in distylous plants.

FOREST NECTAR-POLLINIFEROUS PLANTATIONS OF THE EASTERN PODILLIA

The article highlights the results of research on the state of forest nectar-pollinating plantations and prospects for the development of forestry and beekeeping in the system of the regional eco-network of Eastern Podillia. One of the conditions of Ukraine's European integration is the implementation of measures to comprehensively preserve the biolandscape diversity of the regions, as well as the implementation of greening of production, in particular, forestry on the basis of the inexhaustible use of natural resources. Forestry is characterized by a wide range of production of raw materials, including nectar and pollen, the products of which are processed by honey bees (honey, bee pollen, royal jelly, etc.) are in high demand among the population. Providing their food needs at the expense of forest nectar-polliniferous, bees also maintain ecological balance by preserving their existence. In terms of the forest fund of Eastern Podillia, there are 215,488.1 hectares of land, of which 61% are operational forests, 15% are protective forests, 17% are recreational and health forests, and 7% are nature conservation, scientific, historical and cultural forests. The area of nectarbearing plantations is from 0.8 ha, and mixed plantations - from 0.3 ha to 5.7 ha. Nectaro-pollenbearing forest plantations of Eastern Podillia are represented by 37 introduced tree species. The main nectar- and pollen-bearing plantations of Eastern Podillia include: linden, broadleaved linden, white acacia, varieties of maples, from the nectar and pollen of which bees produce both fodder and commercial honey. Other pollinators provide the bees with a supporting bribe, which makes it possible to provide these insects with food.

The effect of fermented pollen supplements on the percentage of cell acceptance rate and royal jelly production in Iranian honey bees (Apis mellifera meda)

Royal jelly (RJ) is a yellowish-white substance secreted by the secretory glands of young worker bees to feed the larvae and the queen throughout its life. This study investigates the effect of fermented pollen supplementation on RJ production and cell acceptance rate in Iranian honey bees. The experiment was conducted in Marivan, Iran, for 30 days in the summer of 2020. Experimental treatments include (1) control (sugar syrup); (2) pollen cake (raw pollen, powdered sugar, and honey) + sugar syrup; (3) unfermented pollen supplement + sugar syrup; and (4) fermented pollen + sugar syrup. RJ production and cell acceptance rate were measured and estimated at different time intervals. The collected data were analyzed in a completely randomized design using SAS9.4 software using the GLM procedure. The results showed that different experimental treatments had a significant effect (p ≤ 0.05) on the amount of RJ produced. Among various treatments, the highest RJ production was related to the fourth treatment (12.53 g), and the control treatment (8.07 g) had the lowest production rate. In addition, the highest mean percentage of cell acceptance rate (97.58%) was related to the fermented pollen + sugar syrup treatment. The results showed a positive and high correlation between the two traits of cell acceptance rate and RJ production. In general, a fermented supplementary diet is more efficient than unfermented rations with the same ingredients, therefore recommendable for the apiculture industry.

Bee Pollen Extracts: Chemical Composition, Antioxidant Properties, and Effect on the Growth of Selected Probiotic and Pathogenic Bacteria.

This paper evaluated the chemical and biological properties of bee pollen samples from Romania. Firstly, the bee pollen alcoholic extracts (BPEs) were obtained from raw bee pollen harvested by Apis mellifera carpatica bees. The chemical composition of BPE was obtained by determination of total phenol content and total flavonoid content, UHPLC-DAD-ESI/MS analysis of phenolic compounds, and GC-MS analysis of fatty acids, esters, and terpenes. Additionally, the antioxidant activity was evaluated by the Trolox Equivalent Antioxidant Capacity method. Furthermore, the biological properties of BPE were evaluated (antimicrobial and cytotoxic activity). The raw BP samples studied in this paper had significant phenolic acid and flavonoid content, and moderate fatty acid, ester, and terpene content. P1, P2, and P4 have the highest TPC and TFC levels, and the best antioxidant activity. All BPEs studied had antimicrobial activity on pathogenic strains isolated from the clinic or standard strains. A synergistic antimicrobial effect of the BPEs was observed along with the soluble compounds of L. rhamnosus MF9 and E. faecalis 2M17 against some pathogenic (clinical) strains and, considering the tumour proliferation inhibitory activity, makes BP a potential prebiotic and antitumour agent for the gut environment.

Investigation of Hybrid Methods for Elimination of Brilliant Blue Dye from Water Phase Using Various Nanomaterials Combined with Activated Sludge and Duckweed.

The main goal of this experimental work is screening of different natural and synthetic nanomaterials and biopolymers that may improve elimination of stable micropollutants from water phase. In this work, as a target chemical acting as the micropollutant molecule, the Brilliant Blue (BB) dye was selected. We tested different active matrices dispersed in water phase including activated carbon (AC), lyophilized graphene oxide (GO), β-cyclodextrin (CD), raw dandelion pappus (DP), microcrystalline cellulose(MC), and raw pine pollen (PP), as well as two types of Egyptian Blue mineral pigments (EB1 and EB2). Graphene oxide and Egyptian Blue nanomaterials were synthesized in our laboratory. We investigated potential application of such nanoparticles and biopolymer conglomerates as additives that may tune the activated sludge (AS) microorganisms or duckweed water plant (DW) and increase efficiency of micropollutants removal from wastewater. Studied nanomaterials/biopolymers were used in two different experimental modes involving real activated sludge microorganisms (24 h experiment) as well as duckweed plant (16 day experiment). Quantitative data of BB were obtained using microfluidic type device based on micro-TLC plate. This approach enabled direct determination of target component without sample pre-treatment like pre-concentration or pre-purification. Within single analytical run calibration line, retention standard spots (methyl red) and multiple samples were analyzed simultaneously. Due to the multivariate nature of these experiments, quantitative data were explored with chemometric tools including AHC (agglomerative hierarchical clustering), PCA (principal component analysis), and FA (factor analysis). Experimental data and multivariate calculations revealed that BB is strongly resistant on biodegradation, however, inclusion complexes formation with β-cyclodextrinmay induce degradation of this dye in the presence of duckweed. It is hoped that results of our experimental work can be used for designing of future experiments for fast screening of different additives and improvement of technological processes, focusing on purification of sewage and water from micropollutants.

Biomimetic synthesis of C-doped g-C3N4 spinous hollow microspheres from sunflower pollen with enhanced visible-light photocatalytic performance

The C-doped g-C3N4 hybrids were synthesized by using melamine as the raw material and sunflower pollen as the bio-template. At a fixed amount of melamine (1 g), a series of hybrids (g-C3N4/C-X, where X is the weight of pollen) were obtained by varying the dosage of pollen. The g-C3N4/C-0.4 partially reserved the morphology of pollen, that is, spinous hollow microsphere with particle size of 25–30 μm. In comparison with the bulky g-C3N4 gained from melamine and other g-C3N4/C hybrids, the g-C3N4/C-0.4 exhibited highest visible-light photocatlaytic activity for tetracycline hydrochloride degradation. The introduction of pollen not only improved the morphology of bulky g-C3N4, but also improved its photoelectric property. The high visible-light photocatalaytic performance of g-C3N4/C-0.4 could be due to its large specific surface area, strong light absorption ability and high separation efficiency of photo-generated electron-hole pairs derived from the doped C materials which played the role of electron trappers.

Quantifying the impact of chemicals on stable carbon and oxygen isotope values of raw pollen

ABSTRACTPurification protocols to extract pollen from lake sediments contain chemicals that alter the carbon and oxygen pollen‐isotope values according to pollen characteristics and family affiliation. Modern (raw) pollen of broad‐leaved (Alnus glutinosa, Betula pendula, Carpinus betulus, Corylus avellana, Fagus sylvatica and Quercus robur) and coniferous tree species (Picea abies and Pinus sylvestris) were treated with potassium hydroxide (KOH), hydrofluoric acid (HF), sodium hypochlorite (NaClO) and sulphuric acid (H2SO4) to test the impact on δ13Cpollen and δ18Opollen and assess the applicability in purification protocols. Pollen of broad‐leaved and coniferous trees reacted differently to chemical exposure, but response patterns are generally alike. Alterations of δ13Cpollen values vary between + 1.0‰ (B. pendula, NaClO‐treatment) and −5.0‰ (P. sylvestris, H2SO4‐treatment). The δ13Cpollen values of raw and chemically treated samples seem to be related after treatments with KOH, NaClO and HF, whereas the application of H2SO4 led to inconsistent changes among species. The impact of chemicals on δ18Opollen are more diverse and offsets range between +1.1‰ (C. avellana, NaClO‐treatment) and −17.9‰ (P. sylvestris, H2SO4‐treatment). In general, the use of isotope‐altering chemicals in purification protocols should be brought to a minimum, but the application of KOH and NaClO seems mostly unproblematic before δ13Cpollen and δ18Opollen analysis.

Nutrients Bioaccessibility and Anti-inflammatory Features of Fermented Bee Pollen: A Comprehensive Investigation.

We compared raw bee-collected pollen (Raw-BCP), spontaneously fermented BCP (Unstarted-BCP), and BCP fermented with selected microbial starters (Started-BCP) to deepen whether fermentation may favorably affect the nutrients bioaccessibility and functional features of BCP. Under in vitro gastrointestinal batches, the highest serum-availability of phenolic compounds was found in Started-BCP, highlighting the positive effect exerted by selected microbial starters. The same effect was not found in spontaneously fermented BCP. In colon adenocarcinoma cell line-2 (Caco-2) cells stressed by a pro-inflammatory stimulus, the treatment with Started-BCP halted the increase of pro-inflammatory mediator’s level. Started-BCP counteracted efficiently the deleterious effects of inflammatory stimuli on the integrity of the Caco-2 cells monolayer and its barrier function. Started-BCP successfully counteracted the H2O2-induced intracellular accumulation of reactive oxygen species (ROS) in Caco-2 cells. A protective role against lipopolysaccharide (LPS)-induced inflammation was exerted by Started-BCP in human keratinocytes. The same protective effects on Caco-2 and keratinocyte cell lines were negligible after treatments with Raw-BCP or Unstarted-BCP.

Juglans Sporopollenin for High-Performance Supercapacitor Electrode Design.

Recently, plant pollen has been used as a source of activated carbon to produce carbon-containing supercapacitor electrodes. However, in this study, pollen was used as a biotemplate with a completely different approach. As a biotemplate, pollen offers a wide range of varieties in terms of exterior, porosity, shape, and size. An electrode formed by the use of metal oxide grown on the pollen exine layer (sporopollenin microcapsules) as the active substance will inevitably exhibit good electrochemical capacitive properties. Juglans male flowers have been distinguished by dissection from anthers. Isolation of pollen grains from anthers was carried out using sieving from suitable sieves (45–200 μm). Juglans sporopollenin exine microcapsules (SECs) were separated from the intine and protoplasm by acetolysis in combination with reflux. The solution containing SECs, metal ions, and Ni foam was put into a Teflon-lined hydrothermal container, and then, it was reacted at 120 °C for 15 h. The resulting precipitate, as well as the Ni foam, was heat-treated at 300 and 360 °C for 3 h in air. The raw pollen, chemically treated pollen, and cobalt-coated SEC (CoSEC) and CoSEC/Ni foam were characterized using scanning electron microscopy, Brunauer–Emmett–Teller surface area analysis, thermogravimetric analysis, and X-ray diffraction techniques. Two different types of supercapacitor electrode designs, with the use of exine microcapsules of Juglans sporopollenin, were performed for the first time. The maximum specific capacitance was up to 1691 F g–1 at 5 A g–1.

Optimization of hierarchical porous carbon derived from a biomass pollen-cone as high-performance electrodes for supercapacitors

Activated carbons (ACs) with large surface area and hierarchical porous character are the materials of larger interest to use as electrodes in energy storage devices like supercapacitors/ electrical double layer capacitors (EDLCs). Here, we present comparative studies on ACs, derived from a bio-waste pollen cones activated using two activating agents ZnCl2 and KOH, as electrode materials. Optimization of ACs derived from different ratios of raw pollen cone powder and activating agents has been performed by porosity analysis. The AC-powders have been characterized using X-ray diffraction, scanning electron microscopy, Raman and Fourier-transform infra-red spectroscopy. The electrochemical performance of AC-electrodes have been tested by fabricating symmetric configuration of EDLCs with aqueous liquid electrolyte (1 M Na2SO4) and quasi-solid-state, ionic liquid incorporated gel polymer electrolyte (ILGPE). The free-standing film of ILGPE, comprising IL 1-ethyl-3-methyl imidazolium bis(trifluoromethyl sulfonyl)imide (EMITFSI) immobilized in a copolymer poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), is found suitable as EDLC electrolyte due to its flexibility, high ionic conductivity (σ ∼2.4 mS cm−1 at room temperature) and wide electrochemical stability window (∼4.6 V versus Ag). Comparative performance of EDLCs fabricated with AC-electrodes (activated using ZnCl2 and KOH), and aqueous liquid electrolyte and ILGPE have been tested using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge studies. Performance of pollen-cone derived AC-electrodes has also been compared with commercial AC and un-activated pollen-cone carbon-electrodes. The KOH-activated AC-powder shows better capacitive performance over the ZnCl2-activated and commercial ACs with both the electrolytes. The ILGPE-based quasi-solid-state EDLC, although, offers comparable specific capacitance (∼126–146 F g−1), the specific energy (∼18–21 Wh kg−1 at effective power of ∼110–190 W kg−1) is higher compared to aqueous electrolyte-based EDLC. The quasi-solid-state EDLC exhibits 98–100% Coulombic efficiency and stable cyclic performance for ∼10,000 charge-discharge cycles with ∼12% initial fading in capacitance. Thermal stability of ILGPE-incorporated cells is found for wider temperature range, particularly at lower temperatures.

Inter- and intra-tree variability of carbon and oxygen stable isotope ratios of modern pollen from nine European tree species.

Stable carbon and oxygen isotope ratios of raw pollen sampled from nine abundant tree species growing in natural habitats of central and northern Europe were investigated to understand the intra- and inter-specific variability of pollen-isotope values. All species yielded specific δ13Cpollen and δ18Opollen values and patterns, which can be ascribed to their physiology and habitat preferences. Broad-leaved trees flowering early in the year before leaf proliferation (Alnus glutinosa and Corylus avellana) exhibited on average 2.6‰ lower δ13Cpollen and 3.1‰ lower δ18Opollen values than broad-leaved and coniferous trees flowering during mid and late spring (Acer pseudoplatanus, Betula pendula, Carpinus betulus, Fagus sylvatica, Picea abies, Pinus sylvestris and Quercus robur). Mean species-specific δ13Cpollen values did not change markedly over time, whereas δ18Opollen values of two consecutive years were often statistically distinct. An intra-annual analysis of B. pendula and P. sylvestris pollen revealed increasing δ18Opollen values during the final weeks of pollen development. However, the δ13Cpollen values remained consistent throughout the pollen-maturation process. Detailed intra-individual analysis yielded circumferential and height-dependent variations within carbon and oxygen pollen-isotopes and the sampling position on a tree accounted for differences of up to 3.5‰ for δ13Cpollen and 2.1‰ for δ18Opollen. A comparison of isotope ranges from different geographic settings revealed gradients between maritime and continental as well as between high and low altitudinal study sites. The results of stepwise regression analysis demonstrated, that carbon and oxygen pollen-isotopes also reflect local non-climate environmental conditions. A detailed understanding of isotope patterns and ranges in modern pollen is necessary to enhance the accuracy of palaeoclimate investigations on δ13C and δ18O of fossil pollen. Furthermore, pollen-isotope values are species-specific and the analysis of species growing during different phenophases may be valuable for palaeoweather reconstructions of different seasons.

Low temperature and high velocity assisted fluidized bed drying characteristics of bee pollen as bioactive food

AbstractThis study reveals the low temperature high velocity (LTHV) assisted fluidized bed drying can preserve to the bioactive components of bee pollen. LTHV assisted fluidized bed drying characteristics of bee pollen. For this purpose, 100 g of the raw bee pollen samples are used to the investigation of drying characteristics at 4, 10, 24, and 40°C, ~40–50 humidity (%) and 6 m/s air velocity. In this regard, moisture loss, dimensionless mass loss, equilibrium moisture content, drying rate, drying time, mass shrinkage, some product characteristics, and sensory quality characteristic were investigated. Finally, the best drying air temperature was selected as 10°C because the bee pollen samples had the best drying performance and sensory quality scores. LTHV assisted fluidized bed drying can be used for bioactive bee pollen drying.Practical applicationsThe LTHV assisted fluidized bed drying is a new drying application that preserve to the sensitive food and bioactive food component. This method is usable for sensitive drying applications as medical and bioactive product production applications for the highest quality and safety production.

The Inclusion of a Supercritical Fluid Extract, Obtained From Honey Bee Pollen, in the Diet of Gilthead Sea Bream (Sparus aurata), Improves Fish Immune Response by Enhancing Anti-oxidant, and Anti-bacterial Activities

In the present study, the immune-stimulatory effect of two levels of honey bee pollen (5 and 10%, P5 and P10 treatment, respectively) and its supercritical fluid extract (0. 5 and 1%, E0.5 and E1, respectively) included in the diet, was tested in gilthead seabream (Sparus aurata). The in vivo trial was preceded by the evaluation of antioxidant properties of three different bee pollen extracts obtained by water, ethanol 80%, and Supercritic Fluids Extraction (SFE). The preliminary evaluation attested that the SFE showed the lowest extraction yield (10.47%) compared to ethanol 80% (48.61%) and water (45.99%). SFE extract showed good antioxidant properties with high polyphenol content (13.06 mg GAE/g), radical scavenging activity (3.12 mg/ml), reducing power (38.68 mg/mL EC50). On the contrary, the water extract showed the significantly lowest polyphenol content (2 mg GAE/g; P < 0.05). The results of in vivo trial demonstrate that the diets supplemented with SFE bee pollen extract had a stimulatory effect on fish serum immunity, respect to the inclusion of raw pollen, this latter revealing some inhibitory effects in the immune response, such a decrease of serum peroxidase and lysozyme activities, particularly in P10 group significantly different (P < 0.05) from the control group. On the contrary, serum peroxidase, protease, antiprotease, were significantly increased in fish fed the diets supplemented with supercritical fluid extract, respect to the fish fed on control and on diets supplemented with 5 and 10% of raw pollen. For what concerns the bactericidal activity against Vibrio harveyii, all the treatments containing bee pollen regardless of the type showed their serum bactericidal activity significantly increased with respect to the control groups (p < 0.05). Given its high antioxidant properties, the absence of toxic solvents and the positive action carried out on improving the humoral response in gilthead seam bream, honey bee pollen SFE extract can be taken into account in the formulation of fish feeds.

Non-waste technologies for processing bee products (analytical review)

Aim. To review and analyze publications devoted to non-waste technologies for processing propolis and bee pollen. Materials and methods. The research material was foreign and domestic publications on processing bee products. The methods of information retrieval, analysis and generalization were used in the work. Results and discussion. The literature data on the development of technological methods for processing propolis and bee pollen have been presented. The technology of propolis purification from wax components and the optimal conditions for obtaining phenol fractions of propolis (hydrophilic and hydrophobic) have been considered. The non-waste technology for processing the raw propolis and the complex processing of bee pollen are represented on examples. The optimal parameters of the process for obtaining the enzyme substance from bee pollen and the feasibility of its use as a protein feed additive have been analyzed. Conclusions. A review of scientific publications on the development of non-waste technologies for processing bee products has been conducted. The analysis of the studies has shown that the production of medicines based on bee products remains an urgent area of modern pharmacy. A great contribution to the development of this problem was made by the work of O. I. Tikhonov scientific school on the integrated waste-free processing of the raw propolis and bee pollen in order to obtain standardized biologically active substances required for the creation and production of medicines.

Environmental variability in response to abrupt climatic change during the Last Glacial–Interglacial Transition (16–8 cal ka BP): evidence from Mainland, Orkney

The Last Glacial–Interglacial Transition (LGIT) is a period of climatic complexity where millennial-scale climatic reorganization led to changes in ecosystems. Alongside millennial-scale changes, centennial-scale climatic events have been observed within records from Greenland and continental Europe. The effects of these abrupt events on landscapes and environments are difficult to discern at present. This, in part, relates to low temporal resolutions attained by many studies and the sensitivity of palaeoenvironmental proxies to abrupt change. We present a high-resolution palynological and charcoal study of Quoyloo Meadow, Orkney and use the Principal Curve statistical method to assist in revealing biostratigraphic change. The LGIT vegetation succession on Orkney is presented as open grassland and Empetrum heath during the Windermere Interstadial and early Holocene, and open grassland with Artemisia during the Loch Lomond Stadial. However, a further three phases of ecological change, characterized by expansions of open ground flora, are dated to 14.05–13.63, 10.94–10.8 and 10.2 cal ka BP. The timing of these changes is constrained by cryptotephra of known age. The paper concludes by comparing Quoyloo Meadow with Crudale Meadow, Orkney, and suggests that both Windermere Interstadial records are incomplete and that fire is an important landscape control during the early Holocene. Supplementary material : All raw data associated with this publication: raw pollen counts, charcoal data, Principal Curve and Rate of Change outputs and the age-model output are available at https://doi.org/10.6084/m9.figshare.c.4725269 Thematic collection: This article is part of the ‘Early Career Research’ available at: https://www.lyellcollection.org/cc/SJG-early-career-research

Preparation and Release of Vanillin from Sporopollenin Microcapsules

Sporopollenin is a potential carrier for active ingredient due to its uniform size, central cavity, as well as chemical and thermal stability. Sporopollenin microcapsules were obtained by a series of processes on the pollens of Typhae angustfolia. Vanillin was embedded in sporopollenin using passive loading and evaporating techniques. Raw cattail pollen, sporopollenin, vanillin, and vanillin-loaded microcapsules were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The results show that sporopollenin exhibits structural integrity, porosity, and good thermal stability. The encapsulation efficiencies of the microcapsules prepared by passive loading technique and evaporating loading technique were found to be 7.2 ± 0.8% and 40.5 ± 1.6%, respectively. The release profile and kinetics of the vanillin-loaded sporopollenin microcages were conducted to evaluate the suitability of sporopollenin microcapsules for loading. Release behavior of vanillin from microcapsules was more aligned with Fickian diffusion, with an initial rapid cumulative release followed by a lower speed of release. These findings demonstrated that sporopollenin from the cattail pollen of T. angustfolia could be a suitable medium for sustained release of nutritional components.

Effect of Solar Drying Process on Bioactive Compounds and Antioxidant Activity in Vitro of High Andean Region Bee Pollen

Bee pollen is a hive product of common consumption with a known and remarkable content of bioactive and functional compounds, namely carotenoids and phenolic compounds. The bee pollen from the Colombian High Andean region has a prominent content of these compounds due to environmental and botanical conditions. In this work, the process of bee pollen drying by solar dehydration was evaluated to determine its influence on functional compounds and antioxidant activity. This process was carried out in a greenhouse type solar system located in the central region of Colombia into the High Andean region. Drying tests were conducted for two consecutive days during the dry season. The tests were developed for 8h, collecting samples at the beginning (t = 0h) and at the end (t = 8h) of the process. The contents of total carotenoids, total phenol compounds and antioxidant activity in vitro of samples were measured by spectrophotometric standard methods: a spectrophotometric measure of acetone extract for carotenoids, Folin-Ciocalteau for phenol compounds and TEAC/FRAP for antioxidant activity. The content of carotenoids in dry bee pollen was in average 0.9mg s-carotene/g. Besides, the content of phenolic compounds of bee pollen processed in the solar system was 16mg gallic acid/g. The content of carotenoids and phenol compounds in dry bee pollen did not change significantly from initial raw bee pollen. Furthermore, the antioxidant activity of raw bee pollen (0.85mmol Trolox/g) was maintained even after the drying process in the solar dehydration system. The results show that there was no impact of the solar drying process on bioactive compounds content of bee pollen. Therefore, this type of solar drying system is an actual alternative to traditional equipment for bee pollen drying at this region, favoring a lower energy cost and with a no evident influence on the product quality.

PRODUCTION OF POLLEN CANS BY FERMENTATION OF BEE POLLEN IN MODEL CONDITIONS WITH REGARD TO FILAMENTOUS MICROMYCETES OCCURRENCE

Pollen is produced by flowering plants and gathered by bees and it is rich in nutrients and important phytochemicals. Bee collected pollen is used in human nutrition, but the digestibility is limited. The possible solution is the production of fermented pollen cans according to the pattern of bee bread production by bees. The study was devoted to the testing of 3 variants of pollen cans production, from the point of view of filamentous microscopic fungi (FMF) occurrence. Totally 3 types of bee pollen and 3 types of honeys of Slovak origin, water and yoghurt as a starter (in one variant) were used for the production of pollen cans. Raw materials and fermented pollen cans were subjected to mycological analyzes (plate dilution method). Samples of honey and yoghurt were free of FMF. Pollen represents the main potential source of pollen cans contamination. The average count of FMF in pollens was 4.70 log CFU.g-1. The highest number of fungi was found in the late spring bee pollen and Cladosporium spp. occurred with the highest relative density. The counts of FMF were reduced by fermentation and botanical origin of pollen had the greatest impact on their expansion. The greatest diversity of genera was recorded in bee pollen samples, subsequently in pollen cans has declined and after total fermentation was the lowest. Aspergillus spp. were isolated at a low frequency, Alternaria spp. appeared mainly in cans of late spring bee pollen, the highest counts of Penicillium spp. were recorded in cans of early spring bee pollen, in variant with added yoghurt.

The Use of Pistachio Pollen for the Production of Nanostructured Porous Nickel Oxide

Natural biotemplates — such as bacteria, fungi and viruses — are used in nanostructured metal oxide production. The pollen can be found abundantly in nature, and their microcapsules can be easily isolated from the pollen by chemical treatments. To date, pollen microcapsules are mostly used as drug carriers and catalytic agent templates. In the present study, nanoporous-structured nickel oxide is produced using Pistachio pollen microcapsules. The raw pollen, chemically treated pollen and metal-coated pollen were characterized using scanning electron microscopy, Brunauer–Emmett–Teller (BET) surface area analysis, thermogravimetric analysis (TGA), differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. The natural Pistachio pollen which were procured from Gaziantep, Turkey, are spherical, with a diameter of approximately 23[Formula: see text][Formula: see text]m. The maximum surface area obtained for nickel oxide-coated microcapsules is 228.82[Formula: see text]m2/g. This result shows that Pistachio pollen are an excellent candidate for the production of porous nanostructured materials for supercapacitor electrodes.