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“Bee pollen” is pollen collected from flowers by honey bees. It is used by the bees to nourish themselves, mainly by providing royal jelly and brood food, but it is also used for human nutrition. For the latter purpose, it is collected at the hive entrance as pellets that the bees bring to the hive. Bee pollen has diverse bioactivities, and thus has been used as a health food, and even as medication in some countries. In this paper, we provide standard methods for carrying out research on bee pollen. First, we introduce a method for the production and storage of bee pollen which assures quality of the product. Routine methods are then provided for the identification of the pollen’s floral sources, and determination of the more important quality criteria such as water content and content of proteins, carbohydrates, fatty acids, vitamins, alkaloids, phenolic and polyphenolic compounds. Finally, methods are described for the determination of some important bioactivities of bee pollen such as its antioxidant, anti-inflammatory, antimicrobial and antimutagenic properties. Métodos estándar Para la investigación del polen El "polen de abeja" es el polen recogido de las flores por las abejas melíferas. El polen de abeja es utilizado para nutrir a las propias abejas, principalmente para proporcionar jalea real y alimento para las crías, pero también se utiliza para la nutrición humana. Para este último fin, se recoge en la entrada de la colmena en forma de gránulos que las abejas llevan a la colmena. El polen de abeja tiene diversas bioactividades, por lo que se hautilizado como alimento para la salud, e incluso como medicamento en algunos países. En este artículo, proporcionamos métodos estándar para llevar a cabo investigaciones sobre el polen de abeja. En primer lugar, presentamos un método de producción y almacenamiento de polen de abeja que garantiza la calidad del producto. A continuación, se ofrecen métodos de rutina para la identificación de las fuentes florales del

BACKGROUND: The compositional, functional, and nutritional properties of fruits are important for defining their quality. Fruit seeds should be better exploited as they are also considered to be a good source of bioactive components. Twenty macro, micro, and trace elements were identified and quantified in the seeds of 70 genuine wild and cultivated fruit species/cultivars by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Sophisticated chemometric techniques were also used to establish criteria for the classification of the analyzed samples. RESULTS Calcium and P were the most abundant elements, followed by K and Na. The content of microelements and trace elements differed among the different cultivars/genotypes. The content of Ba, Pb, and Sr was significantly higher in wild fruits, whereas Fe, Mg, Mn, Ni and Zn content was higher in cultivated fruits. CONCLUSION All of the statistical procedures that were used - Kruskal-Wallis, Mann-Whitney U-test, and principal component analysis (PCA) - confirm a unique set of parameters that could be used as phytochemical biomarkers to differentiate fruit-seed samples belonging to different cultivars/genotypes according to their botanical origin. This kind of investigation may contribute to intercultivar/genetic discrimination and may enhance the possibilities of acquiring a valuable authenticity factor.

Concerning the particular nutritive value of honeydew honey compared to blossom honey, and small number of studies defining botanical origin of honeydew honey, comprehensive analysis of phenolic profile of 64 honeydew honey samples of specific botanical origin was performed. Two advanced techniques of liquid chromatography hyphenated with mass spectrometry were used for identification of a total of 52 compounds and quantification of 25 of them. Pattern recognition analysis applied on data on phenolic compounds content confirmed that quercetin, naringenin, caffeoylquinic acid, hydroxyphenylacetic acid, apigenin and genistein, could be considered as potential markers of botanical origin of honeydew honey. Spectroscopic and electrochemical approaches were applied for the evaluation of the antioxidant capacity. Quercus sps. samples, Quercus frainetto and Quercus ilex, showed high biological activity and specific chemical composition. Additionally, cyclic voltammetry profiles were used for characterization and natural clustering of honeydew honey for the first time. © 2018 Elsevier Ltd

To contribute to the development of urban beekeeping, we designed this study to obtain more information about the contamination of urban bee products with toxic metals, polycyclic aromatic hydrocarbons (PAHs), and pesticides. The samples of honey (N=23), pollen (N=13), and floral nectar (N=6) were collected from the experimental stationary apiary of the Belgrade University Faculty of Agriculture located in centre of Zemun (a municipality of the Belgrade metropolitan area) in 2015 and 2016. Metals (Pb, Cd, As, Cu, Zn, Fe, Mn, Ni, Cr, and Hg) were determined with inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Polycyclic aromatic hydrocarbons (PAHs) were analysed with high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Pesticides were analysed with gas chromatography - mass spectrometry (GC-MS). The honey samples were generally within the European and Serbian regulatory limits. The levels of all the 123 analysed pesticides were below the limit of quantification (LOQ). Regarding PAH levels in honey, the highest content was found for naphthalene. The elevated levels of Hg and Cr and of PAHs in the pollen samples indicated air pollution. Pesticide residues in pollen, however, were below the LOQ. In nectar, metal levels were relatively similar to those in honey. Our results suggest that the investigated urban honey meets the regulatory requirements for metals, PAHs, and pesticides and is therefore safe for consumption.

This research proposes a new way of tracing differences between potato cultivation systems, botanical origin, and climate conditions by using sugar profiles. A set of 90 potato tubers of four varieties with different ripening times, cultivated in three types of agricultural systems: conventional (C), integral (I), and organic (0) were characterized based on sugar profiles of their bulk and peel. A total of nineteen sugars were quantified. In order to determine the source of variation among the types of production, the years of production and varieties, multivariate analysis of variance (MANOVA) was conducted. The results indicated that starch may be considered an important indicator of the type of production, botanical origin, and ripening time. Additionally, the analyses showed that sugar macro and microcomponents such as fructose, glucose, saccharose, sorbitol, trehalose, arabinose, turanose and maltose were the main factors for the differentiation of production types, production years and botanical origin of potato.

Apricot seeds could be obtained as a byproduct in different juice or conserve producing industries. Disposal of large amount of apricot seeds is wasting of potentially precious sources of phytochemicals. This study encompassed apricot cultivars that have different origin and flowering time with the aim of providing valuable information about the sugar content in its kernels. High-performance anion-exchange chromatography with pulsed amperometric detection was used for the determination of 22 sugars in the kernels of 70 apricot cultivars. The most common sugars in the apricot kernels are sucrose, fructose, and glucose whose ratio proved to be ripening time dependent (1:1:1 in the early, 1:2:3 in medium and 1:3:3 in the late cultivars). The kernels of the apricot with shorter vegetation period had the highest sum of glucose and fructose compared to other groups. Other sugar components were present in different levels as minor constituents depending on the ripening time. Also, most common sugars and some low-level sugars were strongly correlated to each other, indicating the normal metabolic carbohydrate pathway. To understand the distribution modes of sugars, a principal component analysis was performed.

The fatty acid profile, its relation to botanical origin and nutritional characteristics of bee-collected pollen from Serbia was determined. Twenty different fatty acids were detected. Depending on the palynological origin, the fatty acid (FAs) composition varied greatly. Three groups of pollen samples can be differentiated on the basis of Categorical principal component analysis. The first group was characterized by the presence of Fraxinus sp. pollen as predominant type and Zea mays as an accompanying pollen type and a high level of polyunsaturated FAs. Rannunculaceae, Apiaceae and Asteraceae family pollen, Ambrosia, Plantago, Sophora and Helianthus annuus pollen influenced the presence of saturated FAs and separation of the second group of samples. Pollen of plants belonging to the Fabaceae and Brassicaceae families had significant influence on constitution of the third group of samples with saturated and unsaturated FAs. The most abundant saturated, mono- and poly unsaturated fatty acids were palmitic, oleic and linolenic acid, respectively.

Assessment of microbiological quality of bee collected pollen is very important, because of its use as a supplement in the human diet. In this study, 26 samples collected from different location in Serbia were tested for the presence of mold through mycologial analysis. The presence of aflatoxin B1, one of the most dangerous and the most widespread mycotoxin was also determined. It was established that 10 of the investigated samples were contaminated with some genera or species of mold, but all of the investigated samples were contaminated with aflatoxin B1. Considering that there is no unique and official procedure for mycological analysis of bee collected pollen, these findings suggest the need for their establishment. Mycological analysis should be followed by mycotoxicological analysis since the absence of mold does not confirm the absence of aflatoxin B1 in bee pollen.

Propolis, as a beneficial natural product, has found application in the food and pharmaceutical industries as a food preservative, active packaging material as well as a main component of propolis containing products. Quality control of propolis has thus gained in importance. We used simple, fast, and low-cost techniques such as UV/Vis spectrophotometry and cyclic voltammetry applied in combination with principal component analysis to confirm the presence of two botanical sub-types of propolis. Cyclic voltammetry, as a green, sensitive, and convenient technique suitable for investigation of chemical profile, together with multivariate chemometrics technique, was used for the first time for characterization and classification of propolis. UV/Vis spectroscopy was applied in two aspects, absorption at certain wavelength for the quantitative determination of analytes, i.e. determination of quality control parameters, and spectral profiles, for the confirmation of the existence of two botanically different poplar types. All investigated Serbian propolis samples were characterized with specific chemical patterns and were classified in two main botanical varieties, so-called orange and blue. The results confirmed that the applied methods have a potential to be used for the discrimination of complex natural products such as propolis.

Cold stress adversely affects growth and productivity, and triggers a series of morphological, physiological, biochemical and molecular changes in plants. Since sugars are present in all floral nectars in greater amounts than any other constituent, the aim of this study was to examine how frost exposure changes sugar metabolism and how it affects on the content of sugar components in the nectar of quince. Three quince cultivars ('Vranjska', 'Triumph' and 'Leskovac. ka') were investigated in this study. The contents of sugars (glucose, fructose, sucrose, trehalose, maltose, isomaltose, rhamnose, arabinose, ribose, melezitose, raffinose, and panose) and sugar alcohols (sorbitol, erythritol, mannitol and galactitol) were analyzed by high performance anion exchange chromatography (HPAEC) with amperometric detection. The results showed that after late spring frosts and irreversible damage of flower parts, the nectar of the three quince cultivars contained elevated levels of fructose, trehalose, arabinose, ribose, rhamnose, raffinose, galactitol and mannitol, indicating an impairment of central carbohydrate metabolism. The ratios between individual sugars, such as the glucose/fructose ratio, were changed in the nectar of damaged flowers in all three quince cultivars. The examined cultivars showed similar sugar response to cold stress. The only exception was 'Leskovac. ka' for the glucose and melezitose pathway, which means that composition of those two sugars changed significantly according to the genotype. The larger are the carbohydrates reserves in different parts of a fruit tree, the higher is the tolerance to any form of frost damage, the results of this study could help in the understanding of how different quince cultivars react to this kind of stress and how they modulate their sugar metabolism.