Palinomorfološko proučavanje jagorčevine (Primula vulgaris Huds.) sa područja nacionalnog rezervata Obedska bara (Srbija)

The pollen morphology of primrose (Primula vulgaris, fam. Primulaceae) has been investigated using light and scanning electron microscopy to contribute to melissopalynological studies of honeys originating from the native apiflora. Palynomorphological investigation included the examination of pollen symmetry, polarity, ornamentation, aperturation, shape and size. The pollen grains are isopolar, radially symmetric and shed as monads. The exine ornamentation is reticulate. Analysis of pollen morphometric characteristics revealed that grains are small to medium size and prolate in shape. Given the aperturation, the number of colpi was mostly variable among individuals with a different type of flower ranging from 6 to 9.Palinomorfološka istraživanja jagorčevine (Primula vulgaris) koja su obuhvatila analizu osnovnih karakteristika polenovih zrna kao što su simetrija, polarnost, ornamentacija, aperturacija, oblik i veličina, obavljena su uz pomoć svetlosne i skenirajuće elektronske mikroskopije u cilju doprinosa melisopalinološkim istraživanjima meda poreklom iz apiflore različitih područja Srbije. Polenova zrna jagorčevine su izopolarna i radijalno simetrična, retikulatne ornamentacije. U pogledu aperturacije, evidentna je varijabilnost u broju brazdi na polenovim zrnima sakupljenim sa cvetova različitih individua, te su ona 6(-7) ili 8(-9)-zonokolpatna. Analiza morfometrijskih karakteristika polena pokazala je da polenova zrna po veličini spadaju u grupu malih do srednjih i da imaju prolatni oblik

Phytochemical and Antioxidant Properties of Fresh Fruits and Some Traditional Products of Wild Grown Raspberry (Rubus idaeus L.)

The current study investigated and compared phytochemical and antioxidant activity of fresh fruit and some traditional products of Rubus idaeus grown in mountain region of Serbia. The total organic acid, total sugar content, total phenolics, flavonoids, tannins, anthocyanins and vitamin C were evaluated. The antioxidant activities were evaluated using two antioxidant systems 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The fresh fruit contained highest amount of vitamin C (46.62 mg AA g(-1)) and total organic acids (882.22 mg CA g(-1)). The sweet preserve had highest content of total phenolics (200.83 mg GA g(-1)), flavonoids (12.85 mg RU g(-1)) and tannins (39.11 mg g(-1)). The juice had the highest total anthocyanin content (107.22 mu g mL(-1)) and total sugar content (25 degrees Brix). The best antioxidant activity in ABTS assay had juice (IC50 = 4.87 mu mol TE g(-1)), followed by sweet preserve (IC50 = 5.14 mu mol TE g(-1)), almost identical to standard gallic acid. In the DPPH free radical scavenging assay, sweet fruit preserve showed significant better antioxidant activity (IC50 = 41.27 mu g mL(-1)) compared to juice (IC50 = 106.07 mu g mL(-1)) and fresh fruit (IC50 = 294.79 mu g mL(-1)). Our results indicated promising perspectives for usage of R. idaeus fresh fruits and traditional products studied with considerable levels of vitamin C, bioactive compounds and antioxidant activity

Pollen morphology and the flower visitors of Chaerophyllum coloratum L. (Apiaceae)

The pollen features of Chaerophyllum coloratum L., endemic to the Dinaric Alps, have been examined by both light microscopy and scanning electron microscopy in order to contribute to a better understanding of the taxonomic status of the species. Flower visitors have also been observed and analyzed with the aim of clarifying certain pollination aspects of the species including flower attractiveness especially to honeybees, and also in order to ascertain its contribution to the bee pasture. The pollen grains of C. coloratum are isopolar, radially symmetrical and medium sized. Polar axis (P) is 26.83±1.77 μm length, and equatorial diameter (E) is 9.17±0.57 μm length. P/E ratio amounts 2.90±0.10 indicating a perprolate shape. In an equatorial view, the grains are constricted in the equatorial region (bone-shaped), with obtuse polar caps. In polar view, they are triangular with obtuse angles and furrows in the sides of the triangle (interangular). The grains are tricolporate with three straight ectocolpi arranged regularly meridionally, of mean length 14.43±2.17 μm, each of which has one endopore. The characteristic internal thickenings around the protruding, clearly visible endopores (costae) in the constricted equatorial region are obvious in light microscopy. The ornamentation is psilate, irregularly rugulate (“cerebroid”), the exine surface is rather undulating. With regard to the observed fl ower visitors, the following pollination types occurred: melittophily, myophily, sapromyophily, cantharophily, and phalaenophily, and the most frequent pollinator was the honeybee

Edible snail farming in Serbia: Present and future

Snail farming is a type of sustainable animal production, which could become an important source of incomes for the country, and prevent further exhaustion of natural snail populations. It has raised considerable public attention in Serbia. There are over 350 newly registered snail farms that have started production in the past couple of years. The idea of snail farming in Serbia is strongly and erroneously influenced by media, often presented as an low investment cycle, low manpower, and a very advantageous side activity. On the other hand export of snails collected from natural populations has been very profitable in the past decade despite the economic blockade of the country during the 90s. In this paper, beginnings of snail farming in Serbia, problems of investments, production and protection technology, and marketing are discussed. The need of regulation is pointed out

Standard microscopic slide preparation technique as a new and useful tool for analyzing mucilage content in marshmallow root

Marshmallow (Althaea officinalis L.) root is used as a drug in medicine, pharmaceutical, cosmetic as well as in food products, due to the content of mucilage with a broad range of physicochemical properties. Since mucilage content in roots depends on genotype and growing conditions, the quality control is, therefore, one of the major tasks in the rational use of the drug. In this paper we compare data for mucilage content in roots obtained by standard procedure which implies measuring of swelling ratio in dried samples, with anatomical features of roots obtained by different methods for anatomical analysis, and we have shown that anatomical method could be used for determination of mucilage content in marshmallow root

Alien plant species and factors of invasiveness of anthropogenic vegetation in the Northwestern Balkans - a phytosociological approach

We studied the anthropogenic vegetation of the Northwest Balkans in order to determine its susceptibility to invasion by alien plant species. We compiled a dataset of 3089 vegetation plots sampled between 1939 and 2009, recording a set of variables for each sample plot in order to determine which factors have the most effect on a habitat's vulnerability to invaders. We calculated the proportion of native species, archaeophytes and neophytes for each plot. We used regression tree models to determine the site conditions of the most invaded anthropogenic habitats. The sample plots contained an average of 12.7% alien plant species, with a low proportion of archaeophytes (4.3%) and 8.4% neophytes. Local habitat conditions proved to have the largest effect, rather than climatic variables or propagule pressure. The proportion of archaeophytes follows a different pattern than that seen in central and northern Europe, indicating that macroecological factors are more important. Neophytes show a similar distribution to other European locations

Machine learning chemometric model for Raman spectroscopy based honey quality assessment

INTRODUCTION: According to Codex Alimentarius (2001), “Honey is the natural sweet substance, produced by honeybees from the nectar of plants or from secretions of living parts of plants, or excretions of plant-sucking insects on the living parts of plants, which the bees collect, transform by combining with specific substances of their own, deposit, dehydrate, store and leave in honeycombs to ripen and mature”. Honey is mostly made up of sugars, as well as enzymes, amino acids, organic acids, vitamins, aromatic compounds, minerals and carotenoids. It contains a lot of flavonoids and phenolic acids, which have a lot of biological effects and functions such as natural antioxidants, anti-inflammatory and antimicrobial properties. Its composition is particularly variable, depending on its botanical and geographical origins Because of its exclusive flavor and high dietary value, natural honey is more expensive than other sweeteners. This is the reason why honey is a target of adulteration. The problem is that counterfeiting honey is relatively easy, but detection is difficult. Further, the authenticity of honey is a global important problem for commercial producers and consumers. Accordingly, a fast and non-destructive method of detecting counterfeits is needed. OBJECTIVES: The aim of this paper is to verify the possibility of Raman spectroscopy and Support Vector Machine (SVM) for classification of two different honeys and their fake duplicates. For this purpose, meadow and acacia honeys were selected. METHOD / DESIGN: Spectra of homemade and counterfeits honey were recorded using XploRA Raman spectrometer (Horiba Jobin Yvon). Raman scattering was excited by laser at a wavelength of 785 nm equipped with a 600 lines/mm grating; spectra were recorded by applying exposure time 10 s and accumulated from 10 times scans, using 100% filter. Spectral resolution was 3 cm−1 and autocalibration was done each time before recording of spectra by 520.47 cm−1 line of silicon. In order to assess a possible sample inhomogeneity, thirty Raman spectra in the region from 200-3400 cm-1 were recorded for each sample. All spectra were baseline-corrected, normalized and smoothed. After that PCA (Principal component analysis) was conducted and obtained PCs (first two PCs) served as a features for support vector machine (SVM) classification method. Data were divided into training model (70 %) and training data (30 %). Pre-processing was done by Unscrambler X 10.4 software (CAMO software, Norway). In order to determine the best shape of the hyperplane and decision boundary, several kernel function were used: linear, radial basis and polynomial function. The SVM was conducted by Python and Scikit-learn package. RESULTS: Support vector machine showed high accuracy in classification of different honey samples. Accordingly, the best discrimination power showed SVM with polynomial function (100%), followed by radial basis (96.67%) and linear (81.82%)

Natural Macromolecules as Carriers for Essential Oils: From Extraction to Biomedical Application

Essential oils (EOs) and their main constituents, the terpenes, are widely studied, mostly relating to their antioxidant ability and bioactivity, such as antimicrobial, anticancer, anti-inflammatory, and range of other actions in the living systems. However, there is limited information on their bioavailability, especially upon clinical studies. Having in mind both strong biological effects and health benefits of EOs and their specific physicochemical properties (volatility, lipophilic character, low water solubility or insolubility, viscosity, expressed odor, concentration-dependent toxicity, etc.), there is a need for their encapsulation for target delivery. Encapsulation of EOs and their constituents is the prerequisite for enhancing their oxidative stability, thermostability, photostability, shelf life, and biological activity. We considered various carrier types such a (1) monophase and polyphase polysaccharide hydrogel carriers, (2) polysaccharide-protein carriers, and (3) lipid carriers in the context of physicochemical and engineering factors. Physicochemical factors are encapsulation efficiency, chemical stability under gastric conditions, mechanical stability, and thermal stability of carrier matrices. Choice of carrier material also determines the encapsulation technique. Consequently, the engineering factors are related to the advantage and disadvantage of various encapsulation techniques frequently used in the literature. In addition, it was intended to address the interactions between (1) main carrier components, such as polysaccharides, proteins, and lipids themselves (in order to form chemically and mechanically stable structure); (2) main carrier components with pepsin under gastric conditions (in order to form resistant material under gastric conditions); and (3) main carrier components with EOs (in order to enhance encapsulation efficiency), as a necessary precondition for whole process optimization. Finally, different sources for obtaining natural carrier macromolecules are surveyed, especially the agro-waste materials and agricultural and food by-products. This review article highlights the bioavailability aspects of encapsulated EOs and physicochemical and engineering factors concerning natural macromolecule carriers for their target delivery and application

Kinetika sušenja i analiza skupljanja biomaterijala korenja Valeriana officinalis

Drying kinetics and shrinkage of valerian plant root (Valeriana officinalis) was investigated during the convective hot air dryer with forced convection mode. Whole root without cutting, root cut into quarters, and root cut into 2 mm thin slices were used in drying experiments. Initial moisture content of roots was 51.2±0.3% and roots were considered to be dry when they lost 68% of the fresh weight and reached the moisture content of 10%. Drying air temperature was set to be 40 and 50°C, air velocity at 1 m/s. The relative humidity of drying air was not controlled and it depended on surroundings. The experimental results were fitted to the five thin layer drying models and according to the non-linear regression analysis Page model was most suitable to describe the drying kinetics. The characteristic drying curves were created for each experimental set and they showed that the samples' preparation strongly influenced the drying process and drying time. Experiments to determine shrinkage of different cell structures of valerian root were carried out for raw material, as well as for dried samples, by using optical and electron microscopy observations and measurements. It was observed that shrinkage processes are significantly dependent of the type of cell tissue and drying air temperature.Istraživanje kinetike sušenja i analiza skupljanja biomaterijala korenja lekovitog bilja Valeriana officinalis izvršeno je na konvektivnoj sušari sa vrućim vazduhom kao agensom sušenja. U eksperimentima su korišćeni uzorci: ceo koren, koren sečen na četvrtine i koren sečen na uzorke debljine 2 mm. Početni sadržaj vlage u uzorcima iznosio je 51.2±0.3%, a uzorak se smatrao suvim onda kada sadržaj vlage opadne na 10%. Temperatura vazduha u sušari iznosila je 40 i 50oC, sa brzinom strujanja od 1 m/s. Relativna vlažnost vazduha koji dospeva na materijal nije kontrolisana i zavisila je od spoljnih uslova. Eksperimentalni rezultati su analizirani kroz pet najčešće korišćenih modela za opisivanje promene bezdimenzionog sadržaja vlage u vremenu kod sušenja u tankom sloju, pri čemu je ustanovljeno da se kinetika sušenja najbolje opisuje modelom Page-a. Postupcima optičke i elektronske mikroskopije izvršeno je posmatranje uzoraka svežeg i osušenog korenja pri različitim režimima sušenja u cilju praćenja skupljanja materijala. Ustanovljeno je da proces skupljanja bitno zavisi od vrste ćelijskog tkiva u posmatranom poprečnom preseku materijala i od temperaturnog režima sušenja

Raman spectroscopy coupled with chemometric modeling approaches for authentication of different paprika varieties at physiological maturity

Five Balkan paprika varieties at physiological maturity were investigated by means of Raman spectroscopy in order to discriminate the differences which stemmed from their genetic variability since the plants were grown under the same experimental conditions. The spectra were obtained using the 532 nm wavelength. In an effort to find the best classification power, several pre-processing methods were applied: 1) baseline correction, unit vector normalization; 2) baseline correction, unit vector normalization and first Savitzky-Golay derivative; 3) baseline correction, unit vector normalization and second Savitzky-Golay derivative; 4) baseline correction, unit vector normalization and third Savitzky-Golay derivative. All of the pre-processing methods were followed by making PCA-LDA (Principal Component Analysis-Linear Discriminant Analysis), QDA (Quadratic Discriminant Analysis), and PLS-DA (Partial Least Square - Discriminant Analysis) classification models. QDA showed the best discrimination power (83.87–100% and 89.47–100% for the training and the test data, respectively), then PCA-LDA (0.00–100 and 0.00–100% for the training and the test data, respectively) and PLS-DA (19.35–100% and 0.00–100.00% for the training and the test data, respectively). The results pointed out the applicability of chemometric modeling associated with Raman spectroscopy in the assessment of nutritionally similar samples, such as the studied red paprika varieties