40 research outputs found

    Antioxidant properties of bee products derived from medicinal plants as beekeeping sources

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    Plant species are fundamental source of nectar in beekeeping since bees access nectar and pollen from flowers. Consequently, bee products are strongly linked to the bee foraging flora source, and, depending on this, they acquire defined features, including their health and medicinal properties. Medicinal plants contribute greatly to increase the beneficial properties of bee products, such as honey, pollen, royal jelly, and propolis. Bee products represent a potential source of natural antioxidants that can counteract the effects of oxidative stress underlying the pathogenesis of many diseases. The antioxidant properties of bee products have been widely studied and there is an abundance of information available in the literature. Notwithstanding, the uniqueness of the presented perspective is to provide an updated overview of the antioxidant properties of bee products derived from medicinal plants as beekeeping sources. This topic is divided and discussed in the text in different sections as follows: (i) beekeeping and the impacts of environmental factors; (ii) an overview of the role of medicinal plants for bee products; (iii) definition and categorization of the main medicinal bee plants and related bee products; (iv) the study approach of the antioxidant properties; (v) the conventional and innovative assays used for the measurement of the antioxidant activity; and (vi) the antioxidant properties of bee products from medicinal plants.info:eu-repo/semantics/publishedVersio

    Physico-Chemical Parameters, Phenolic Profile, In Vitro Antioxidant Activity and Volatile Compounds of Ladastacho (<i>Lavandula stoechas</i>) from the Region of Saidona

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    The aim of the present study was to characterize Lavandula stoechas (Ladastacho) from the region of Saidona by means of physico-chemical parameters, phenolic profile, in vitro antioxidant activity and volatile compounds. Physico-chemical parameters (pH, acidity, salinity, total dissolved solids, electrical conductivity and liquid resistivity) were determined using conventional methods. The phenolic profile was determined using high-performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), whereas a quantitative determination was also accomplished using the total phenolics assay. In vitro antioxidant activity was determined using the 2,2-diphenyl-1-picryl-hydrazyl assay. Finally, volatile compounds were determined using headspace solid phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME/GC-MS). The results showed that Lavandula stoechas aqueous extract had a slightly acidic pH, low salinity content and considerable electrochemical properties (electrical conductivity and liquid resistivity along with electric potential). In addition, aqueous fractions showed a significantly (p &lt; 0.05) higher phenolic content and in vitro antioxidant activity, whereas phenolic compounds, such as caffeic acid, quercetin-O-glucoside, lutelin-O-glucuronide and rosmarinic acid, were identified. Finally, numerous volatile compounds were found to dominate the volatile pattern of this flowering plant, producing a strong, penetrating, cool and menthol-like odour

    Discrimination of Clover and Citrus Honeys from Egypt According to Floral Type Using Easily Assessable Physicochemical Parameters and Discriminant Analysis: An External Validation of the Chemometric Approach

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    Twenty-two honey samples, namely clover and citrus honeys, were collected from the greater Cairo area during the harvesting year 2014&ndash;2015. The main purpose of the present study was to characterize the aforementioned honey types and to investigate whether the use of easily assessable physicochemical parameters, including color attributes in combination with chemometrics, could differentiate honey floral origin. Parameters taken into account were: pH, electrical conductivity, ash, free acidity, lactonic acidity, total acidity, moisture content, total sugars (degrees Brix-&deg;Bx), total dissolved solids and their ratio to total acidity, salinity, CIELAB color parameters, along with browning index values. Results showed that all honey samples analyzed met the European quality standards set for honey and had variations in the aforementioned physicochemical parameters depending on floral origin. Application of linear discriminant analysis showed that eight physicochemical parameters, including color, could classify Egyptian honeys according to floral origin (p &lt; 0.05). Correct classification rate was 95.5% using the original method and 90.9% using the cross validation method. The discriminatory ability of the developed model was further validated using unknown honey samples. The overall correct classification rate was not affected. Specific physicochemical parameter analysis in combination with chemometrics has the potential to enhance the differences in floral honeys produced in a given geographical zone

    Prickly Pear Seed Oil by Shelf-Grown Cactus Fruits: Waste or Maste?

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    The chemical composition and properties of seed oils have attracted researchers nowadays. By this meaning, the physicochemical and bioactivity profile of prickly pear seed oil (PPSO) (a product of prickly pear fruits waste) were investigated. Seeds of shelf-grown cactus fruits (Opuntia ficus indica L.) were subjected to analysis. Moisture content (gravimetric analysis), seed content (gravimetric analysis), oil yield (Soxhlet extraction/gravimetric analysis), volatile compounds (HS-SPME/GC-MS), fatty acids profile (GC-FID), in vitro antioxidant activity (DPPH assay), and total phenolic content (Folin-Cioacalteu assay) were determined. Results showed that prickly pear seeds had a moisture content of 6.0 &plusmn; 0.1 g/100 g, whereas the oil yield ranged between 5.4 &plusmn; 0.5 g/100 g. Furthermore, the PPSO had a rich aroma because of acids, alcohols, aldehydes, esters, hydrocarbons, ketones, and other compounds, with the major volatiles being 2-propenal, acetic acid, pentanal, 1-pentanol, hexanal, 2-hexenal, heptanal, 2-heptenal (Z), octanal, 2-octenal, nonanal, 2,4-decadienal (E,E), and trans-4,5-epoxy-(E)-2-decenal. Among the fatty acids, butyric, palmitic, stearic, and oleic acids were the dominant. Finally, the pure PPSO had a high in vitro antioxidant activity (84 &plusmn; 0.010%) and total phenolic content (551 &plusmn; 0.300 mg of gallic acid equivalents/L). PPSO may be then used as a beneficial by-product, in different food systems as a flavoring, antioxidant, and nutritional agent

    Bio-Functional Properties of Bee Pollen: The Case of “Bee Pollen Yoghurt”

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    The objectives of the present work were: (a) to characterize bee pollen from the region of Epirus in terms of biofunctional activity parameters as assessed by (i) the determination of specific polyphenols using high performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), (ii) antioxidant capacity (DPPH assay), and (iii) total phenolic content (Folin-Ciocalteu assay), and (b) to prepare yoghurts from cow, goat, and sheep milk supplemented with different concentrations of grounded bee pollen (0.5, 1.0, 2.5 and 3.0%, w/v), and study afterwards the trend in antioxidant capacity and total phenolic content along with product&#8217;s sensory properties. Results showed that bee pollen ethanolic extracts are a rich source of phytochemicals based on the high total phenolic content and in vitro antioxidant activity that were monitored. The addition of grounded bee pollen in yoghurts resulted in a food matrix of a higher in vitro antioxidant capacity and total phenolic content, whereas it improved the yoghurt&#8217;s taste, odour, appearance, and cohesion; the latter indicates its beneficial use as a general food surface and interface material enhancer due to the possible formation of surface/interface active lipid-linked proteins. Based on the present findings, bee pollen yoghurt is proposed as a novel and costless functional food whereas it may comprise a research basis for food or material science in the scientific society of the future. Results were further supported by implementation of advanced chemometric analyses providing a full characterization of the product&#8217;s uniqueness

    Use of Fe (II) and H<sub>2</sub>O<sub>2</sub> along with Heating for the Estimation of the Browning Susceptibility of White Wine

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    The aim of the present study was to investigate if the use of Fe (II) and H2O2 (Fenton reaction) along with heating can be implicated for the rapid evaluation of the browning susceptibility of white wine. In this context, increasing concentrations of Fe (II) and H2O2 were added to two white wines (Roditis–Malagouzia and Debina), the samples were stored at 45 °C or 18 °C, and the absorbance at 420 nm (browning index) was measured. Moreover, total sulfur dioxide, total phenolics, flavanols, hydroxycinnamates and total free sulfhydryls were assessed during storage of Roditis–Malagouzia wine samples. The results showed that the addition of Fe (II) + H2O2 mixture in white wines increases rapidly the browning index at 45 °C, indicating the ability to develop a rapid test for the estimation of the browning susceptibility of white wines. Results also showed that the level of flavanols is a suitable index to follow the forced oxidative browning of white wine by adding Fe II + H2O2 at 45 °C. Moreover, results indicated that the levels of total free sulfhydryls may be a suitable index to follow the forced oxidative browning of white wine and in general, white wine oxidation

    Characterization of Eucalyptus, Chestnut and Heather Honeys from Portugal Using Multi-Parameter Analysis and Chemo-Calculus

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    The present study was conducted to evaluate the quality and bio-functional properties of Portuguese honeys of different botanical and geographical origins. Quality parameter analyses included the determination of palynological (predominant, secondary, minor and isolated pollen percentage), physicochemical (&#176;Brix, moisture content, pH, electrical conductivity, free acidity, total dissolved solids, salinity, vitamin C content and specific weight) including colour-metrics (CIELAB, Pfund and colour intensity determinations), along with volatile compounds identification using solid phase micro-extraction coupled to gas chromatography mass spectrometry. Bio-activity parameter analysis included the determination of in vitro antioxidant activity and total phenolic content using the 2,2-diphenyl-1-picryl-hydrazyl and Folin-Ciocalteu assays, respectively. Melissopalynological analysis showed that Portuguese honeys were classified as eucalyptus, chestnut and heather, recording significant variations (p &lt; 0.05) among physicochemical, volatile and bio-activity parameter analyses according to both: botanical and geographical origin. Based on the multi-parameter analysis data Portuguese honeys could be characterized by a distinctive colour, a characteristic aroma, whereas conform to the European legislation relating to honey identity and quality. Specific attention should be given in the case of heather honey which showed the highest in vitro antioxidant activity and total phenolic content. Parameters that were also highly correlated using bivariate statistics

    An Exploratory Research Regarding Greek Consumers’ Behavior on Wine and Wineries’ Character

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    Given the lack of data regarding the preferences, behavior and habits of wine consumers in Greece, the purpose of the present study was to investigate consumer trends and explore the factors that affect the purchase and consumption of wine in comparison with other alcoholic beverages. For this purpose, a self-response questionnaire survey was designed through the Google platform on a sample of 994 participants. In order to analyze the collected data, statistical analysis was done. A second online questionnaire was introduced to Greek winery companies. The purpose was to examine if the wine producers follow the wine consumption trends according to the desires of the Greek wine consumers or are addressed to a more international audience. As for the wine companies’ perspectives, we wanted to collect data regarding the amount of their production and the type of wine they produce and to know about their profile (international, exports, strategies, etc.). We collected 71 responses from wineries located in different parts of Greece. For the first time in the last 10 years, there is a profile of Greek consumers’ behavior toward wine in comparison with other alcoholic beverages and knowledge of specific operational data of Greek wineries using an online questionnaire survey (e-survey)

    The impact of geographical origin on specific properties of pine honey

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    Pine honey represents the major type of honey produced in Greece. In that sense, the aim of the present study was to investigate if specific physicochemical and bioactive properties could serve as markers of its geographical origin. For this purpose, forty pine honey samples were collected during harvesting years 2011 and 2012 from Halkidiki and Thassos, the well-known pine honey producing areas in Greece. Physicochemical parameters taken into account, using conventional and literature cited methods, were: pH, CIE colour parameters L*,a*,b*, and browning index. Furthermore, colour intensity and the in vitro radical scavenging activity were estimated by the application of spectrometric assays. Results showed that, pine honeys exhibited statistically significant differences (p&lt;0.05) in pH, colour intensity, and radical scavenging activity, depending on geographical origin. On the basis of radical scavenging activity results obtained, pine honeys proved to have a high in vitro antioxidant &ldquo;character&rsquo;&rsquo;. Finally, perfect Pearson&rsquo;s correlations (r=1) at the confidence level p&lt;0.01 were obtained for the sets: pH-browning index, pH-radical scavenging activity, and browning index -radical scavenging activity, with respect to geographical origin
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