Suchergebnisse

This study describes the possibilities of valorising a waste stream that originates from apple wood by mapping the reducing capacity and phenolic profile from extracts derived from apple tree (Malus domestica). This study evaluated the efficiency of warm solvent extraction (WSE) and ultrasound-assisted extraction (UAE) techniques for extracting antioxidant phenolic compounds from the bark and core wood of an apple tree cultivated in the north-eastern part of Belgium. Furthermore, the influence of the pre-treatment technique, namely, fresh, oven-dried, and freeze-dried samples, respectively, on the yield of polyphenols was studied. Fresh bark extract obtained by UAE—the most efficient extraction technique—employing acetone 60% v/v contains the highest levels of phenolic compounds as well as the highest antioxidant activity. High-performance liquid chromatographic analysis shows that phloridzin is the major compound of the identified polyphenol markers present in bark and core wood extracts. Based on the obtained results, it may be possible to produce a polyphenolic extract from apple wood at an industrial scale without extensive costs or altering the antioxidant properties. This study reveals the potential of apple tree wood residues valorisation through the recovery of phenolic compounds for food, pharmaceutical, and cosmetic applications. ; Annick Boeykens is a beneficiary of a PWO ('Projectmatig Wetenschappelijk Onderzoek') Grant, provided to Odisee by the Flem-ish Government, for the investigation project 'Phenolic compounds in by-products'. Manuela M. Moreira (SFRH/BPD/97049/2013) wishes to acknowledge Fundo Social Europeu and Ministério da Ciência, Tecnologia e Ensino Superior for funding her postdoctoral fellowship by means of a POPH-QREN—Tipologia 4.1—Formação Avançada. The financial support from FCT/MEC through national funds and cofi-nanced by FEDER, under the Partnership Agreement PT2020 through the project UID/QUI/50006/2013—POCI/01/0145/FEDER/007265 and the project 6818—Transnational Cooperation, Agreement between Por-tugal (FCT) and Serbia (MSTD) are also acknowledged. ; info:eu-repo/semantics/publishedVersion

Brewer's spent grain (BSG), obtained from barley malt during brewing, contains high amounts of phenolic acids, predominantly ferulic and p-coumaric acids. The protective effects of BSG extracts against oxidative DNA damage induced by H2O2 in Saccharomyces cerevisiae cells were investigated using an optimized yeast comet assay and flow cytometry. The results indicated that BSG extracts from black malt exhibited a 5-fold reduction in the genotoxic effects of H2O2, compared to the 2-fold decrease by the BSG extracts from pilsen malts. Flow cytometry analysis with dichlorofluorescein diacetate demonstrated that the intracellular oxidation of S. cerevisiae is also reduced to approximately 50% in the presence of 20-fold diluted BSG extracts. BSG extracts obtained from pilsen and black malt types exert dose-dependent protective properties against the genotoxic effects induced by ROS and decrease intracellular oxidation of yeast cells. ; This work received financial support from the European Union (FEDER Funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e a Tecnologia) through project Pest-C/EQB/LA0006/2013 and PEst-C/BIA/UI4050/2011. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124-FEDER-000069. DOC receives a postdoc grant through the project Operação Norte-01-0145-FEDER-000011. MMM wishes to acknowledge to FCT for her postdoctoral grant (SFRH/BPD/97049/2013). The authors also thank Unicer – Bebidas de Portugal, S. A. for the supply of BSG samples. ...

The aim of this study was to evaluate the influence of lyophilization and drying in stove on phenolic compounds content and the biological activity of Apis mellifera and Trigona spinipes pollens produced in Brazil. In general, the bee pollen produced by T. spinipes presented highest antioxidant activity in dried and fresh samples assessed either by test of plasma ferric reduction capacity (FRAP) and free radical scavenging assay (DPPH) methods. For A. mellifera bee pollen the antioxidant activity was higher on the fresh samples. Nevertheless, b-carotene bleaching assay (BCB) and linoleic acid content were higher in T. spinipes samples, mainly in the fresh ones. Higher antioxidant activity was owing to higher content in phenolic compounds. Lyophilization method was the best for phenolic compounds' conservation for both species. The bee pollen of both species has a high amount of flavonoids: kaempferol-3-O-glucoside was the most abundant in A. mellifera while for T. spinipes the most prevalent was resorcylic acidþepicatechin. All extracts presented antibacterial activity against Saphylococcus aureus (ATCC 43300)TM, (ESA 83138150), (ESA 32), Pseudomonas aeruginosa (ATCC 15442)TM, Pseudomonas aeruginosa (MRC.4) and (MRC.10). The methods used for storage influenced the biological properties of bee pollen from both species. Regarding the content of phenolic compounds, differences were observed amongst the pollen types: for A. mellifera these were best preserved with lyophilization, while for T. spinipes the three storage methods were equivalent. ; The authors are grateful to the Coordenac¸~ao de Aperfeic¸oamento de Pessoal de N ıvel Superior – CAPES (88881.062167/2014-01 for M.L.M.E.). A. Pascoal would like to thank Foundation for Science and Technology (FCT, Portugal), Programa Operacional Potencial Humano (POPH), and European Union (EU) for his Postdoctoral grant SFRH/BPD/ 91380/2012. ; info:eu-repo/semantics/publishedVersion