Spectroscopic Discrimination of Bee Pollen by Composition, Color, and Botanical Origin

Bee pollen samples were discriminated using vibrational spectroscopic methods by connecting with botanical sources, composition, and color. SEM and light microscope images of bee pollen loads were obtained and used to assess the botanical origin. Fourier transform (FT) mid- and near-infrared (FT-MIR, FT-NIR), and FT-Raman spectra of bee pollen samples (a set of randomly chosen loads can be defined as an independent sample) were measured and processed by principal component analysis (PCA). The CIE L*a*b* color space parameters were calculated from the image analysis. FT-MIR, FT-NIR, and FT-Raman spectra showed marked sensitivity to bee pollen composition. In addition, FT-Raman spectra indicated plant pigments as chemical markers of botanical origin. Furthermore, the fractionation of bee pollen was also performed, and composition of the fractions was characterized as well. The combination of imaging, spectroscopic, and statistical methods is a potent tool for bee pollen discrimination and thus may evaluate the quality and composition of this bee-keeping product

Chemical Composition and Rheological Properties of Seed Mucilages of Various Yellow- and Brown-Seeded Flax (Linum usitatissimum L.) Cultivars

When seeds sown in the soil become wet, their hulls secrete viscous matter that can retain water and thus support germination. Flaxseed mucilage (FSM) is an example of such a material and is attractive for food, cosmetic, and pharmaceutical applications due to its suitable rheological properties. FSM consists mainly of two polysaccharides, namely, arabinoxylan and rhamnogalacturonan I, and it also contains some proteins, minerals, and phenolic compounds. The genotype and the year of the flax harvest can significantly affect the composition and functional properties of FSM. In this work, FSM samples were isolated from flax seeds of different cultivars and harvest years, and their structural and rheological properties were compared using statistical methods. The samples showed significant variability in composition and rheological properties depending on the cultivar and storage time. It was found that the ratio of two polysaccharide fractions and the contribution of less-prevalent proteins are important factors determining the rheological parameters of FSM, characterizing the shear-thinning, thixotropic, and dynamic viscoelastic behavior of this material in aqueous solutions. The yield strength and the hysteresis loop were found to be associated with the contribution of the pectin fraction, which included homogalacturonan and rhamnogalacturonan I. In contrast, the shear-thinning and especially the dynamic viscoelastic properties depended on the arabinoxylan content. Proteins also affected the viscoelastic properties and maintained the elastic component of FSM in the solution. The above structural and rheological characteristics should be taken into account when considering effective applications for this material

Screening of the Chemical Composition and Identification of Hyaluronic Acid in Food Supplements by Fractionation and Fourier-Transform Infrared Spectroscopy

Hyaluronic acid, together with collagen, vitamins or plant extracts, is a part of many cosmetic and food preparations. For example, this polysaccharide is used in formulation of many food supplements due to its protective effects on human health. In this work, the screening of the chemical composition of three chosen dietary supplements (powder, tablets and capsules) containing hyaluronic acid was carried out using Fourier-transform infrared spectroscopy. Because of the low amount of analyte in all these samples, it was isolated or concentrated prior to the analysis using a suitable sequential fractionation protocol. Individual isolation procedures were established for each sample based on their declared composition. Firstly, the major components such as collagen or vitamins were removed to obtain polysaccharide fractions by the enzymatic treatment and/or washing out with the appropriate solvents. In some cases, the water insoluble part was removed from the rest dissolved in water. Then, hyaluronic acid was precipitated with copper(II) cations and thus separated from the other polysaccharides. Finally, the analyte was identified in the enriched fractions by the characteristic vibrational bands. The amount of hyaluronic acid in the purified fractions was determined in three ways: gravimetrically, spectrophotometrically, and using isotachophoresis. The combination of the appropriate preparative and analytical steps led to the successful evaluation of chemical composition, finding and quantification of hyaluronic acid in all the studied samples

Morphological characteristic of fruit, drupes and seeds genotypes of Ziziphus jujuba Mill.

The aim of this work is to discriminate 28 Ziziphus jujuba Mill. genotypes (ZJ-01 - ZJ-28) based on weight and morphological characteristics of fruit, stones and seeds. These genotypes maintained in a clone repository (Nova Kachovka, Ukraine) were chosen for investigation as potential species for cultivation and use in Slovakia. The fruits were collected at the period of their full maturity (October); their morphometric parameters were following: weight from 2.90 g (ZJ-13) to 28.99 g (ZJ-22), length from 20.73 mm (ZJ-08) to 44.84 mm (ZJ-04), and width from 16.64 mm (ZJ-13) to 38.87 mm (ZJ-22). Isolated stones were also analysed, and their weight was from 0.173 g (ZJ-07) to 0.731 g (ZJ-20), length from 12.84 mm (ZJ-08) to 28.67 mm (ZJ-04), and width from 5.06 mm (ZJ-07) to 9.74 mm (ZJ-01). The weight of the seeds was ranging from 20.00 mg (ZJ-25) to 69.11 mg (ZJ-12), length from 7.24 mm (ZJ-15) to 11.85 mm (ZJ-04), and width was from 3.86 mm (ZJ-05) to 6.84 mm (ZJ-12). Significant differences in the size, shape and color of fruits, stones and seeds were also identified. The pulp, seedless stones and seeds constitute 92.81% (ZJ-26) - 98.32% (ZJ-04), 1.36% (ZJ-04) - 6.27% (ZJ-20), and 0.25% (QA-24, QA-25) - 1.21% (ZJ-16) of the total fruits weight, respectively The shape index of the fruits was found in the range of 1.04 (ZJ-08) to 2.00 (ZJ-12 and ZJ-25). The shape indexes of stones and seeds were found ranging from 1.74 (ZJ-08) to 4.53 (ZJ-05) and from 1.32 (ZJ-23) to 2.74 (ZJ-04), respectively. The relative weight of pulp was determined in the range from 92.76% (ZJ-13) to 98.32% (ZJ-04) and the relative weight of seed was determined in the range of 0.25% (ZJ-24 and ZJ-25) to 1.16% (ZJ-26). The Chinese jujube genotypes of this study were grouped based on hierarchical clustering of the fruit, stone and seed characteristics

Hydrocolloids from the Mushroom <i>Auricularia heimuer</i>: Composition and Properties

The ear- to shell-shaped fruiting bodies of the genus Auricularia are widely used as food and in traditional medicinal remedies. This study was primarily focused on the composition, properties and potential use of the gel-forming extract from Auricularia heimuer. The dried extract contained 50% soluble homo- and heteropolysaccharides, which were mainly composed of mannose and glucose, acetyl residues, glucuronic acid and a small amount of xylose, galactose, glucosamine, fucose, arabinose and rhamnose. The minerals observed in the extract included approximately 70% potassium followed by calcium. Among the fatty and amino acids, 60% unsaturated fatty acids and 35% essential amino acids could be calculated. At both acidic (pH 4) and alkaline (pH 10) conditions, the thickness of the 5 mg/mL extract did not change in a temperature range from −24 °C to room temperature, but decreased statistically significantly after storage at elevated temperature. At neutral pH, the studied extract demonstrated good thermal and storage stability, as well as a moisture retention capacity comparable to the high molecular weight sodium hyaluronate, a well-known moisturizer. Hydrocolloids that can be sustainably produced from Auricularia fruiting bodies offer great application potential in the food and cosmetic industries

Using different physical treatments to modify the structure and improve the technofunctional properties of clementine by-products

[EN] Clementine by-products are an important source of dietary fiber, which has different technofunctional properties depending on its chemical composition and structure. These properties can be modified through different treatments. In this work, the impact of treatments such as hot air drying (HAD), homogenization (HOM), freeze drying (FD), and extrusion (EXT) was evaluated on the structure and technofunctional properties of clementine by-products' powders, to promote their use as ingredients in food development as a way of valorization. The structure of by-products was studied using microscopy (Light Microscopy and Field Emission Scanning Electron Microscopy) and vibrational spectroscopic (FTIR and FT-Raman) techniques. The technofunctional properties, water and oil holding capacities, water solubility, swelling capacity, and emulsifying capacity, as well as particle size were evaluated. HOM and EXT showed a more stratified and porous structure than HAD and FD. FTIR and FT-Raman showed that the by-products mainly comprised pectin and cellulose. Regarding technofunctional properties, HOM powders had high water retention and swelling capacities, and good emulsifying capacity even when using high amounts of oil in an emulsion (75 %). FD powders showed the highest oil retention capacity and EXT powders the highest water solubility.This research was funded by grant (RTI2018-099738-B-C22) funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe" and grant (FPU19/03803) funded by MCIN/AEI/10.13039/501100011033 and by "ESF Investing in your future". The authors want to thank Phillip Bentley for his assistance in correcting the manuscript's English. The authors acknowledge the donation of citrus pomace from the Zumos Valencianos del Mediterraneo S.L.com pany.Martínez-Martí, J.; Panu Ková, K.; Larrea Santos, V.; Bleha, R.; Quiles Chuliá, MD.; Hernando Hernando, MI. (2023). Using different physical treatments to modify the structure and improve the technofunctional properties of clementine by-products. Food Structure. 38. https://doi.org/10.1016/j.foostr.2023.1003463

Antimicrobial activity of crude extracts prepared from fungal mycelia

Objective: To evaluate the in vitro antimicrobial property of three different partitioned extracts (petroleum ether, ethanol and water) prepared from some fungal mycelia. Methods: Seven fungal mycelia were prepared, initially extracted with acidified ethanol (0.2 mol/L HCl in 80% ethanol), yielding the raw crude extracts. The obtained extracts were then further partitioned with petroleum ether (F1), ethanol (F2) and water (F3). All the fractions were tested for antimicrobial activity using the disc diffusion assay. Results: Our data showed that all the fractions could inhibit the testing bacteria. However, the inhibitory activity was found to be dependent on (i) the fungal strains used; (ii) the solvent extracted; and (iii) the testing bacteria assayed. In general, the ethanolic extracts (F2) derived from all fungi displayed highest inhibitory activity against the testing bacteria except for Chaetomium sp. Conclusions: The findings of the present study concluded that the extracts prepared from the fungal mycelia had the bioactive compounds with antibacterial property. This study is a pioneering work and further study should be carried out for development of the new drug leads

Birds girdling activity on exotic tree species as a form of adaptive behavior?

Four tree species in the Kostelec n. . l. arboretum (Czech Republic) have been repeatedly damaged by Dendrocopos medius. The unique aspect of this otherwise common behavior called girdling consists in regularly visiting the same trees every spring, although there are more than 1.200 tree species within the arboretum. We monitored transpiration, leaf phenology and the chemical composition of the xylem sap of girdled and nongirdled trees. Spectral analysis revealed slightly higher amounts of sugars, especially saccharose, in Cladrastis Raf. as the most regularly girdled tree among other conditions, comparing girdled to non-girdled trees. Higher transpiration rates were not confirmed in connection with girdling-quite the opposite-Cladrastis Raf. as the most highly favored tree for girdling showed the lowest transpiration rates (in average 6 kg water per day within spring months) compared to other non-girdled trees. We presume that the birds do not choose a particular tree on the basis of any visible or chemical traits but they examine many trees within their territory. Afterwards they probably remember the position of trees whose xylem sap starts to flow early in the spring compared to other trees, as their transpiration stream is enriched with sweet organic substances that represent an advantage for the forthcoming nesting period

Polysaccharides from Basidiocarps of the Polypore Fungus Ganoderma resinaceum: Isolation and Structure

In this study, we focused on the isolation and structural characterization of polysaccharides from a basidiocarp of polypore fungus Ganoderma resinaceum. Polysaccharide fractions were obtained by successive extractions with cold water at room temperature (20 &deg;C), hot water under reflux (100 &deg;C), and a solution of 1 mol L&minus;1 sodium hydroxide. The purity of all fractions was controlled mainly by Fourier transform infrared (FTIR) spectroscopy, and their composition and structure were characterized by organic elemental analysis; neutral sugar and methylation analyses by gas chromatography equipped with flame ionization detector (GC/FID) and mass spectrometry detector (GC/MS), respectively; and by correlation nuclear magnetic resonance (NMR) spectroscopy. The aqueous extracts contained two main polysaccharides identified as a branched O-2-&beta;-d-mannosyl-(1&rarr;6)-&alpha;-d-galactan and a highly branched (1&rarr;3)(1&rarr;4)(1&rarr;6)-&beta;-d-glucan. Mannogalactan predominated in the cold water extract, and &beta;-d-glucan was the main product of the hot water extract. The hot water soluble fraction was further separated by preparative anion exchange chromatography into three sub-fractions; two of them were identified as branched &beta;-d-glucans with a structure similar to the corresponding polysaccharide of the original fraction. The alkaline extract contained a linear (1&rarr;3)-&alpha;-d-glucan and a weakly branched (1&rarr;3)-&beta;-d-glucan having terminal &beta;-d-glucosyl residues attached to O-6 of the backbone. The insoluble part after all extractions was identified as a polysaccharide complex containing chitin and &beta;-d-glucans

Evaluation of the Cultivated Mushroom Pleurotus ostreatus Basidiocarps Using Vibration Spectroscopy and Chemometrics

Fruiting bodies (basidiocarps) of the cultivated mushroom Pleurotus ostreatus (16 strains) were characterized by vibration spectroscopy and chemometrics. According to organic elemental analysis and Megazyme assay, the basidiocarps contained ~6.2&ndash;17.5% protein and ~18.8&ndash;58.2% total glucans. The neutral sugar analysis confirmed that glucose predominated in all the samples (~71.3&ndash;94.4 mol%). Fourier-transformed (FT) mid- and near-infrared (FT MIR, FT NIR) and FT Raman spectra of the basidiocarps were recorded, and the characteristic bands of proteins, glucans and chitin were assigned. The samples were discriminated based on principal component analysis (PCA) of the spectroscopic data in terms of biopolymeric composition. The partial least squares regression (PLSR) models based on first derivatives of the vibration spectra were obtained for the prediction of the macromolecular components, and the regression coefficients R2 and root mean square errors (RMSE) were calculated for the calibration (cal) of proteins (R2cal 0.981&ndash;0.994, RMSEcal ~0.3&ndash;0.5) and total glucans (R2cal 0.908&ndash;0.996, RMSEcal ~0.6&ndash;3.0). According to cross-validation (CV) diagnosis, the protein models were more precise and accurate (R2cv 0.901&ndash;0.970, RMSEcv ~0.6&ndash;1.1) than the corresponding total glucan models (R2cv 0.370&ndash;0.804, RMSEcv ~4.7&ndash;8.5) because of the wide structural diversity of these polysaccharides. Otherwise, the Raman band of phenylalanine ring breathing vibration at 1004 cm&minus;1 was used for direct quantification of proteins in P. ostreatus basidiocarps (R ~0.953). This study showed that the combination of vibration spectroscopy with chemometrics is a powerful tool for the evaluation of culinary and medicinal mushrooms, and this approach can be proposed as an alternative to common analytical methods