Morphological, Physicochemical and FTIR Spectroscopic Properties of Bee Pollen Loads from Different Botanical Origin

Impact of green techniques on intricate cell wall structure of bee pollen to enhance functional characteristics and improve its in vitro digestibility

Bee pollen is a nutrient-rich super food, but its rigid dual-layered structure limits nutrient release and absorption. The outer exine, composed of stress-resistant sporopollenin, and the inner intine, consisting of cellulose and pectin, form a barrier to digestive breakdown. This study investigates the potential of green techniques, specifically supercritical fluid extraction and ultrasonication, to disaggregate pollen cell walls, enhancing its bioavailability and maximizing nutrient utilization. Ultrasonication treated pollen (USTP) and supercritical fluid extraction-treated pollen (STP) demonstrated disruption, as evidenced by scanning electron microscopy imaging. In relation to scanning electron microscopy, techno-functional, antioxidant, and compositional analysis displayed a positive outcome, with crude lipid, protein, antioxidant activity (2,2-diphenyl-1-picrylhydrazyl activity and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid assay) and total phenolic content increased by 34.80%, 32.58%, 10.80%, 11.37%, and 83.94%, respectively. Based on the above properties, USTP for 4 h and STP at 400 bar for 40 min were identified as the optimal conditions for disintegration. Furthermore, optimized samples analyzed for amino acid and mineral release revealed a notable increase in composition of essential amino acid and minerals (Ca, Cu, Fe, etc.) by ∼1.5 and 1.2 times, respectively. Along with significant changes in composition, fractured pollen exhibited 1.4 folds increase in protein digestibility with minor differences in thermal stability, and crystallinity as established by differential scanning calorimetry, and X-ray diffraction analysis. The study confirms that nutrient release and absorption remain restricted without pre-treatment, highlighting the necessity of specific treatment to disintegrate bee pollen before its use as a functional food ingredient. PRACTICAL APPLICATION: Bee pollen is a rich source of all the essential nutrients required by the humans and recognised as a complete food. However, its tough cellular structure restricts its utilisation in numerous food applications. Therefore, to disintegrate bee pollen and release its nutrients, ultrasonication and super critical fluid extraction processes were employed to improve its utilization for human purposes. Both the treatment techniques, enhanced bee pollen's bioavailability and functional properties, making it more suitable for use in nutraceuticals and functional foods.These treatments proved to increase the antioxidant capacity, digestibility, and create high-value ingredient for supplements, beverages, and fortified foods.

The volatile and sensory profiles of Tuscan bee pollens stored at different temperatures

The healthy properties of bee pollen mainly depend on the botanical, geographical origin and storage conditions. This study aimed to characterise the composition of volatile compounds and describe the sensory profile of Tuscan bee pollens collected in two different areas in the same period and stored for six months under different conditions. The headspace solid-phase microextraction (HS-SPME) analyses of volatile compounds showed that non-terpene derivatives represented the predominant chemical class in all examined samples, among which aldehydes were the main compounds. Apocaroteonids and oxygenated monoterpenes were also present in lower percentages, with strong separation of the chemical profiles between room temperature samples and those of other storage conditions. The sensory profile was analysed by panel test, the bee pollen produced in the suburban area seemed to show less attractiveness, taste and olfactory. Both samples stored at room temperature showed the worst sensory profile, compared to the other storage conditions.

Exploring the Botanical Origins of Bee-Collected Pollen: A Comprehensive Historical and Contemporary Analysis

Bee-collected pollen is one of the most important bee products. In order to predict its chemical composition and nutritional value botanical origin of pollen plays a crucial role. This review intended to collect all available data published about botanical origin of pollen collected all around the world. Due to enourmous amount of data and variables nonlinear principal component analysis (NLPCA), by applying Categorical Principal Component Analysis (CATPCA), was conducted in order to try to determine any specifity and/or differences among samples. Also, importance of some plant families/genera/species for bees was monitored. Based on CATPCA results families can serve in order to distinct samples from North/South America. Also, some samples from Europe (Turkey and Serbia) were characterized with presence of some specific families. Genera were excellent tool to distinguish samples from different parts of Brazil as well as Australia, Asia and Africa. Due to high and specific biodiversity pollen samples obtained from Sonoran desert (USA) completely were separated during analysis. This review presents the first attempt to summarize and classify a large number of data about botanical sources of bee-collected pollen.

Bee Bread: A Promising Source of Bioactive Compounds with Antioxidant Properties-First Report on Some Antimicrobial Features

Bee bread has received attention due to its high nutritional value, especially its phenolic composition, which enhances life quality. The present study aimed to evaluate the chemical and antimicrobial properties of bee bread (BB) samples from Romania. Initially, the bee bread alcoholic extracts (BBEs) were obtained from BB collected and prepared by Apis mellifera carpatica bees. The chemical composition of the BBE was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and the total phenols and flavonoid contents were determined. Also, a UHPLC-DAD-ESI/MS analysis of phenolic compounds (PCs) and antioxidant activity were evaluated. Furthermore, the antimicrobial activity of BBEs was evaluated by qualitative and quantitative assessments. The BBs studied in this paper are provided from 31 families of plant species, with the total phenols content and total flavonoid content varying between 7.10 and 18.30 mg gallic acid equivalents/g BB and between 0.45 and 1.86 mg quercetin equivalents/g BB, respectively. Chromatographic analysis revealed these samples had a significant content of phenolic compounds, with flavonoids in much higher quantities than phenolic acids. All the BBEs presented antimicrobial activity against all clinical and standard pathogenic strains tested. Salmonella typhi, Candida glabrata, Candida albicans, and Candida kefyr strains were the most sensitive, while BBEs' antifungal activity on C. krusei and C. kefyr was not investigated in any prior research. In addition, this study reports the BBEs' inhibitory activity on microbial (bacterial and fungi) adhesion capacity to the inert substratum for the first time.

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

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.

Metric and Spectral Insight into Bee-Pollen-to-Bee-Bread Transformation Process

Due to numerous bioactive constituents, both bee pollen (BP) and bee bread (BB) represent valuable food supplements. The transformation of BP into BB is a complex biochemical in-hive process that enables the preservation of the pollen's nutritional value. The aim of this study was to determine the depth of the honeycomb cells in which bees store pollen and to provide a spectral insight into the chemical changes that occur during the BP-to-BB transformation process. This study was carried out on three experimental colonies of Apis mellifera carnica, from which fresh BP was collected using pollen traps, while BB samples were manually extracted from the cells two weeks after BP sampling. The samples were analyzed using infrared (FTIR-ATR) spectroscopy, and the depth of the cells was measured using a caliper. The results showed that the average depth of the cells was 11.0 mm, and that the bees stored BB up to an average of 7.85 mm, thus covering between ⅔ and ¾ (71.4%) of the cell. The FTIR-ATR analysis revealed unique spectral profiles of both BP and BB, indicating compositional changes primarily reflected in a higher water content and an altered composition of the carbohydrate fraction (and, to a lesser extent, the lipid fraction) in BB compared to BP.

Investigating the influence of diet diversity on infection outcomes in a bumble bee (Bombus impatiens) and microsporidian (Nosema bombi) host-pathogen system

Diet can have an array of both direct and indirect effects on an organism's health and fitness, which can influence the outcomes of host-pathogen interactions. Land use changes, which could impact diet quantity and quality, have imposed foraging stress on important natural and agricultural pollinators. Diet related stress could exacerbate existing negative impacts of pathogen infection. Accounting for most of its nutritional intake in terms of protein and many micronutrients, pollen can influence bee health through changes in immunity, infection, and various aspects of individual and colony fitness. We investigate how adult pollen consumption, pollen type, and pollen diversity influence bumble bee Bombus impatiens survival and infection outcomes for a microsporidian pathogen Nosema (Vairimorpha) bombi. Experimental pathogen exposures of larvae occurred in microcolonies and newly emerged adult workers were given one of three predominantly monofloral, polyfloral, or no pollen diets. Workers were assessed for size, pollen consumption, infection 8-days following adult-eclosion, survival, and the presence of extracellular microsporidian spores at death. Pollen diet treatment, specifically absence of pollen, and infection independently reduced survival, but we saw no effects of pollen, pollen type, or pollen diet diversity on infection outcomes. The latter suggests infection outcomes were likely already set, prior to differential diets. Although infection outcomes were not altered by pollen diet in our study, it highlights both pathogen infection and pollen availability as important for bumble bee health, and these factors may interact at different stages of bumble bee development, at the colony level, or under different dietary regimes.

Non-Targeted Detection and Quantification of Food Adulteration of High-Quality Stingless Bee Honey (SBH) via a Portable LED-Based Fluorescence Spectroscopy

Stingless bee honey (SBH) is rich in phenolic compounds and available in limited quantities. Authentication of SBH is important to protect SBH from adulteration and retain the reputation and sustainability of SBH production. In this research, we use portable LED-based fluorescence spectroscopy to generate and measure the fluorescence intensity of pure SBH and adulterated samples. The spectrometer is equipped with four UV-LED lamps (peaking at 365 nm) as an excitation source. Heterotrigona itama, a popular SBH, was used as a sample. 100 samples of pure SBH and 240 samples of adulterated SBH (levels of adulteration ranging from 10 to 60%) were prepared. Fluorescence spectral acquisition was measured for both the pure and adulterated SBH samples. Principal component analysis (PCA) demonstrated that a clear separation between the pure and adulterated SBH samples could be established from the first two principal components (PCs). A supervised classification based on soft independent modeling of class analogy (SIMCA) achieved an excellent classification result with 100% accuracy, sensitivity, specificity, and precision. Principal component regression (PCR) was superior to partial least squares regression (PLSR) and multiple linear regression (MLR) methods, with a coefficient of determination in prediction (R2p) = 0.9627, root mean squared error of prediction (RMSEP) = 4.1579%, ratio prediction to deviation (RPD) = 5.36, and range error ratio (RER) = 14.81. The LOD and LOQ obtained were higher compared to several previous studies. However, most predicted samples were very close to the regression line, which indicates that the developed PLSR, PCR, and MLR models could be used to detect HFCS adulteration of pure SBH samples. These results showed the proposed portable LED-based fluorescence spectroscopy has a high potential to detect and quantify food adulteration in SBH, with the additional advantages of being an accurate, affordable, and fast measurement with minimum sample preparation.

Characterisation of Bee Pollen from the Marche Region (Italy) According to the Botanical and Geographical Origin with Analysis of Antioxidant Activity and Colour, Using a Chemometric Approach

Attempts have often been made to isolate and characterise monofloral pollens to correlate nutritional with botanical properties. Nevertheless, pollen harvested in a particular area that can have a high biodiversity could have healthier properties. In addition, the analysis of the pollen's botanical composition can be important for characterising the typical flora of a specific geographical area. On this basis, various pollens collected in different locations of the Marche region (Italy) and in different harvesting periods were analyzed for botanical composition and antioxidant (total phenolic content, ABTS, DPPH and ORAC tests), granulometry and colour (CIE L*a*b*) properties to evaluate the biodiversity of pollen sources within a particular geographical area and to correlate this to the nutraceutical characteristics. Antioxidant activity results showed values generally higher than those of monofloral pollens harvested in the same areas but manually separated according to colour, shape and size. This suggests that even the floral species present in low percentages may have an influence on the nutraceutical properties of these products. The multivariate statistical elaboration of the obtained results permitted the separation of samples containing a prevalent botanical species and the grouping of all the samples into separate clusters corresponding to different areas of Marche.

Exploring the Palynological, Chemical, and Bioactive Properties of Non-Studied Bee Pollen and Honey from Morocco

Bee products are known for their beneficial properties widely used in complementary medicine. This study aims to unveil the physicochemical, nutritional value, and phenolic profile of bee pollen and honey collected from Boulemane–Morocco, and to evaluate their antioxidant and antihyperglycemic activity. The results indicate that Citrus aurantium pollen grains were the majority pollen in both samples. Bee pollen was richer in proteins than honey while the inverse was observed for carbohydrate content. Potassium and calcium were the predominant minerals in the studied samples. Seven similar phenolic compounds were found in honey and bee pollen. Three phenolic compounds were identified only in honey (catechin, caffeic acid, vanillic acid) and six phenolic compounds were identified only in bee pollen (hesperidin, cinnamic acid, apigenin, rutin, chlorogenic acid, kaempferol). Naringin is the predominant phenolic in honey while hesperidin is predominant in bee pollen. The results of bioactivities revealed that bee pollen exhibited stronger antioxidant activity and effective α-amylase and α-glycosidase inhibitory action. These bee products show interesting nutritional and bioactive capabilities due to their chemical constituents. These features may allow these bee products to be used in food formulation, as functional and bioactive ingredients, as well as the potential for the nutraceutical sector.

Rapid and Accurate Approach for Honeybee Pollen Analysis Using ED-XRF and FTIR Spectroscopy

Since honeybee pollen is considered a “perfectly complete food” and is characterized by many beneficial properties (anti-inflammatory, antioxidant, anti-bacterial, etc.), it has begun to be used for therapeutic purposes. Consequently, there is a high need to develop methods for controlling its composition. A thorough bee pollen analysis can be very informative regarding its safety for consumption, the variability of its composition, its biogeographical origin, or harvest date. Therefore, in this study, two reliable and non-destructive spectroscopy methods, i.e., ED-XRF and ATR–FTIR, are proposed as a fast approach to characterize bee pollen. The collected samples were derived from apiaries located in west-central Poland. Additionally, some commercially available samples were analyzed. The applied methodology was optimized and combined with sophisticated chemometric tools. Data derived from IR analyses were also subjected to two-dimensional correlation spectroscopy. The developed ED-XRF method allowed the reliable quantification of eight macro- and micro-nutrients, while organic components were characterized by IR spectroscopy. Principal component analysis, cluster analysis, and obtained synchronous and asynchronous maps allowed the study of component changes occurring dependently on the date and location of harvest. The proposed approach proved to be an excellent tool to monitor the variability of the inorganic and organic content of bee pollen.

Characterization of Bee Pollen: Physico-Chemical Properties, Headspace Composition and FTIR Spectral Profiles

Chemical characterization of bee pollen is of great importance for its quality estimation. Multifloral and unifloral bee pollen samples collected from continental, mountain and Adriatic regions of Croatia were analyzed by means of physico-chemical, chromatographic (GC-MS), and spectroscopic (FTIR-ATR) analytical tools, aiming to conduct a comprehensive characterization of bee pollen. The most distinctive unifloral bee pollen with regard to nutritional value was Aesculus hippocastanum (27.26% of proteins), Quercus spp. (52.58% of total sugars), Taraxacumofficinale (19.04% of total lipids), and Prunusavium (3.81% of ash). No statistically significant differences between multifloral and unifloral bee pollen from different regions were found for most of the physico-chemical measurement data, with an exception of melezitose (p = 0.04). Remarkable differences were found among the bee pollen HS VOCs. The major ones were lower aliphatic compounds, monoterpenes (mainly linalool derivatives, especially in Prunusmahaleb and P.avium bee pollen), and benzene derivatives (mainly benzaldehyde in T.officinale and Salix spp.). Aldehydes C₉ to C₁₇ were present in almost all samples. FTIR-ATR analysis revealed unique spectral profiles of analyzed bee pollen exhibiting its overall chemical composition arising from molecular vibrations related to major macromolecules-proteins, lipids, and carbohydrates (sugars).

Antioxidant Activity Level, Bioactive Compounds, Colour and Spectroscopic Analysis (UV-Vis and FT-IR) of Flavoured Drinks Made with Wine and Sour Cherries (Prunuscerasus Var. austera)

In recent years, the increase in consumer interest towards simpler and authentic lifestyles has led to an explosive growth in the production and business of typical agri-food products and, among these, of wines and its derived beverages. With the aim of promoting a typical Italian beverage, the so-called “Vino di visciole” or “Visner”, listed in the national table of traditional agri-food products, the antioxidant and colour properties of fifteen samples from different provinces of the Marche region and obtained with different recipes were analysed. The “in vitro” total antioxidant activity (TAA) determined using ABTS assays, total phenolic content (TPC), total flavonoid content (TFC), total anthocyanins content (TAC), and colour (Somers assay) were measured. In addition, a spectroscopic FT-IR and UV-Vis analysis was carried out to analyse samples with multivariate techniques. The results showed that the production area, the recipe, and the type of cherries used to make the alcoholic beverage do not influence the antioxidant properties and the phytochemical contents of the samples. The multivariate treatment of the spectroscopic features (mainly UV-Vis) rather allowed the differentiation of samples with high antioxidant activity using easy and low-cost instrumental techniques that require little time and can be employed in routine analysis.

Development of a New Pasta Product by the Incorporation of Chestnut Flour and Bee Pollen

This work aimed at developing fortified pastas incorporating chestnut flour (25–55%) and powdered pollen (5–20%), either separately or in combination, as well as the characterization of the products obtained. To this, a physical characterization was carried out (analyzing texture and color), complemented with chemical analyses to determine the nutritional composition. Results showed that adding chestnut flour over 40% to wheat-flour pasta shortened optimum cooking time and lowered cooking yield, and the addition to pasta prepared with wheat flour and eggs maintained approximately constant the cooking yield. Additionally, the incorporation of pollen powder (up to 20%) in pasta prepared with wheat flour and water or fresh egg shortened the cooking time and cooking yield, in both fresh and dried pasta. The most suitable percentages of the new ingredients were 50% for chestnut and 10% for pollen. Comparing with the control pasta recipe (wheat flour and egg), the addition of chestnut flour (50%) or pollen powder (10%) increased stickiness, adhesiveness and the darkening of the final product (fresh or dried) but maintained the firmness of the pasta. The cooking of fresh or dried pasta enriched with both ingredients turned the pasta clearer and slightly stickier. On the other hand, the addition of chestnut flour and pollen powder in pasta formulation delivered a nutritionally balanced product with high fiber, vitamins and minerals. Overall, chestnut flour and powdered pollen represent promising ingredients for the development of functional fresh and dried pasta formulations.

Impact of Germination on the Microstructural and Physicochemical Properties of Different Legume Types

The microstructural and physicochemical compositions of bean (Phaseolus vulgaris), lentil (Lens culinaris Merr.), soybean (Glycine max L.), chickpea (Cicer aretinium L.) and lupine (Lupinus albus) were investigated over 2 and 4 days of germination. Different changes were noticed during microscopic observations (Stereo Microscope, SEM) of the legume seeds subjected to germination, mostly related to the breakages of the seed structure. The germination caused the increase in protein content for bean, lentil, and chickpea and of ash content for lentil, soybean and chickpea. Germination increased the availability of sodium, magnesium, iron, zinc and also the acidity for all legume types. The content of fat decreased for lentil, chickpea, and lupine, whereas the content of carbohydrates and pH decreased for all legume types during the four-day germination period. Fourier transform infrared spectroscopic (FT-IR) spectra show that the compositions of germinated seeds were different from the control and varied depending on the type of legume. The multivariate analysis of the data shows close associations between chickpea, lentil, and bean and between lupine and soybean samples during the germination process. Significant negative correlations were obtained between carbohydrate contents and protein, fat and ash at the 0.01 level.

Amino Acid Profiling and Chemometric Relations of Black Dwarf Honey and Bee Pollen

This research reports the characterization of bee pollen of Apis andreniformis colonies on the basis of morphology, proximate composition, the amino acid, and nutritive patterns in relation with their honey. The pollen gains of the sampling colonies revealed variations in their structure, symmetry, and sculpture. The exile surfaces of the pollens showed psilate, scabrate, clavate, and echinate types of morphology. Total amino acid content of black dwarf honeybee collected pollen (150 mg/g) was found significantly higher than that of honey (15 mg/g) from the same colony. Threonine, phenylalanine, and leucine were among the highest essential amino acid types found in the analyzed pollen and honey samples. The proline content in both products was found the lowest comparing to other amino acid types. The moisture content of the honey samples were found to exceed the limit as prescribed by Codex Alimentarius Commission (<20%). The ash content of the analyzed samples was mostly within the limits (<0.6%) prescribed by international norms. The fat content of the pollens varied from 5.01 to 5.05%, and the honey showed zero fat content. The carbohydrate content in the honey samples was found to differ significantly from each other with a maximum content (73.16%), and the lowest carbohydrate content was 67.80%. The pollen and honey samples were found to have positive effect on in vitro digestibility of proteins.

Classification of Bee Pollen and Prediction of Sensory and Colorimetric Attributes-A Sensometric Fusion Approach by e-Nose, e-Tongue and NIR

The chemical composition of bee pollens differs greatly and depends primarily on the botanical origin of the product. Therefore, it is a crucially important task to discriminate pollens of different plant species. In our work, we aim to determine the applicability of microscopic pollen analysis, spectral colour measurement, sensory, NIR spectroscopy, e-nose and e-tongue methods for the classification of bee pollen of five different botanical origins. Chemometric methods (PCA, LDA) were used to classify bee pollen loads by analysing the statistical pattern of the samples and to determine the independent and combined effects of the above-mentioned methods. The results of the microscopic analysis identified 100% of sunflower, red clover, rapeseed and two polyfloral pollens mainly containing lakeshore bulrush and spiny plumeless thistle. The colour profiles of the samples were different for the five different samples. E-nose and NIR provided 100% classification accuracy, while e-tongue > 94% classification accuracy for the botanical origin identification using LDA. Partial least square regression (PLS) results built to regress on the sensory and spectral colour attributes using the fused data of NIR spectroscopy, e-nose and e-tongue showed higher than 0.8 R² during the validation except for one attribute, which was much higher compared to the independent models built for instruments.

Bee Bread: Physicochemical Characterization and Phenolic Content Extraction Optimization

Beebread or ambrosia is a unique product for humans and bees, which is the result of lactic fermentation on pollen in honeycombs. Bee bread is a rich source of nutrients (proteins, vitamins) and polyphenols (such as flavonoids, flavonols, phenolic acids). This study aimed to characterize bee bread in terms of physicochemical properties: pH, free acidity, glucose, fructose, sucrose, raffinose and melesitose content, total phenolic content (TPC), total flavones content (TFC), fatty acids and individual phenolics (gallic acid, protocatechiuc acid, p-hydroxybenzoic acid, caffeic acid, vanillic acid, chlorogenic acid, p-coumaric acid, rosmarinic acid, myricetin, luteolin, quercetin and kaempferol). The main phenolic compound identified in the bee bread was kaempferol, followed by myricetin and luteolin. The TPC, TFC and extraction yield were optimized in function of ultrasonic amplitude, temperature and time and the suitable conditions for achieving the maximum level were 87.20% amplitude of ultrasonic treatment, 64.70 °C and 23.10 min, respectively for reaching 146.2 mg GAE/L of TPC, 1231.5 mg QE/g of TFC and a 5.72% extraction yield. The most abundant fatty acids were C18:3 (all-cis-9,12,15) octadeca-6,9,15-trienoic acid, followed by C16:1 (9Z)-hexadec-9-enoic acid, C21:0 heneicosanoic acid and C18:2 (all-cis-9,12) (9Z,12Z)-octadeca-9,12-dienoic acid, respectively.

Ultrasound-Assisted Extraction of Polyphenols From Crude Pollen

The aim of this study was to evaluate the extraction efficiency of polyphenols from crude pollen by an ultrasonic process. Prior to the polyphenols extraction, the crude pollen was defatted. The extraction from defatted pollen was carried out by varying four extraction parameters: ultrasonic amplitude (20%, 60% and 100%), solid/liquid ratio (10 g/L, 20 g/L and 30 g/L), temperature (35, 50 and 65 °C) and time (10, 20 and 30 min). The extracts were analyzed in terms of extraction yield (%), total phenolic content (TPC) and total flavones content (TFC). The extracted oil was analyzed in terms of fatty acids composition; myristic acid (159.1 µg × g^-1) and cis-14-pentadecenoic acid (106.6 µg·g^-1) were found in the highest amount in the pollen oil. The optimum conditions of extraction were determined and were, as follows: 100% amplitude of ultrasonic treatment, 30 g/L solid/liquid ratio, 40.85 °C and 14.30 min, which led to the extraction of 366.1 mg GAE/L of TPC and 592.2 mg QE/g of TFC, and also to an extraction yield of 1.92%.

Chemical and cytological evaluation of honeybee pollen antioxidant ability

The crude flavonoid extract of pollen (CFP) of four species of honeybee pollens were extracted with ethanol, and the total flavonoid contents ranged from 3.4 to 14.5 mg rutin/g dry weight. The antioxidant activities of the CFPs were evaluated from both chemical and cytological aspects. Comprehensive antioxidant scores were determined based on these two evaluation systems. The results showed that canola CFP had the highest antioxidant capacity among the four CFPs. A cytotoxicity assay was conducted to assess the safety threshold of the CFPs, and canola CFP was proved to be the least toxic to vascular endothelial cell. Of the four tested CFPs, this research suggests that canola CFP is the most promising natural antioxidant. In addition, high-performance liquid chromatography (HPLC) analysis detected seven flavonoid glycosides in the hydrolysates of the four CFPs. Among them, quercetin and kaempferol were present in all four honeybee pollen extracts, but there were significant differences between their contents. A correlation analysis revealed a strong correlation between the content of quercetin in the pollen extract and the extract's antioxidant activity. PRACTICAL APPLICATION: Many varieties of honeybee pollen are commercially available. The results of this study help guide consumers to choose honeybee pollens that have a better antioxidant effect. This report can also provide guidance and data in support of the development of honeybee pollen health products.

Phenolic Composition Influences the Health-Promoting Potential of Bee-Pollen

Information on compositional, nutritional and functional properties of bee-pollen, as a health-promoting food, is essential for defining its quality. Concerning the nutritional importance of phenolic compounds, the aim of this study was to determine the phenolic profile and antioxidant activity of twenty-four bee-pollen samples collected from different regions of Serbia. High-performance thin-layer chromatographic (HPTLC) fingerprinting was used for profiling of bee-pollen samples according to the botanical type. HPTLC hyphenated with image analysis and a pattern recognition technique confirmed the grouping of samples caused by the specific phenolic composition of pollens of different botanical origin. Flavonoid glycosides in bee-pollen samples were identified by applying ultra-high-performance liquid chromatography (UHPLC) coupled with linear ion trap-Orbitrap mass spectrometry (LTQ Orbitrap MS). Eight out of twenty-seven flavonol glycosides were identified in bee-pollen samples for the first time. All analyzed bee-pollen samples showed a high number of phenolic compounds which may have therapeutic potential.