120 research outputs found

    Photochemical Energy Conversion with Artificial Molecular Machines

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    The exploitation of sunlight as a clean, renewable, and distributed energy source is key to facing the energetic demand of modern society in a sustainable and affordable fashion. In the past few decades, chemists have learned to make molecular machines, that is, synthetic chemical systems in which energy inputs cause controlled movements of molecular components that could be used to perform a task. A variety of artificial molecular machines operated by light have been constructed by implementing photochemical processes within appropriately designed (supra)molecular assemblies. These studies could open up new routes for the realization of nanostructured devices and materials capable to harness, convert, and store light energy

    Effects of in vitro digestion on the antioxidant activity of three phenolic extracts from olive mill wastewaters

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    The aim of this study was to assess the impact of in vitro digestion on the antioxidant activity of three extracts rich in phenols (two purified organic extracts (A20, A21) and one powdered extract stabilized with maltodextrins (SP)) obtained from olive mill wastewaters (OMWW). The content and composition of phenols and antioxidant activity was determined before and after in vitro digestion. The phenol content of the A20 and A21 samples were higher (>75%) than that of the SP sample before in vitro digestion. After the entire in vitro digestion, 89.3, 76.9, and 50% loss of phenols was found in A20, A21 and SP, respectively. ABTS•+ and ORAC values decreased during in vitro digestion of A20 and A21 samples, while they remained almost constant in SP. IC50 increased during digestion of A20 and A21, evidencing a loss of antioxidant capacity after the intestinal phase; an opposite IC50 trend was noted in SP, confirming the protective role of maltodextrins. For these reasons, SP represents a promising formulation to be used in the food field

    Effect of different irrigation volumes during fruit development on quality of virgin olive oil of cv. Frantoio

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    An experiment was carried out in a high-density olive (Olea europaea L. cv. Frantoio) orchard to determine the effect of different irrigation regimes (full, deficit, complementary) on virgin olive oil (VOO) quality over three consecutive years. Irrigation had negligible effects on free acidity, peroxide value, and fatty acid composition of VOO, but strongly influenced its phenolic concentration. Trees with high water status yielded oils with lower concentrations of total phenols and O-diphenols with respect to oils from severely stressed trees. The concentrations of secoiridoids, like the dialdehydic form of decarboxymethyl elenolic acid linked to (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA), the isomer of the oleuropein aglycon (3,4-DHPEA-EA) and the dialdehydic form of decarboxymethyl elenolic acid linked to (p-hydroxyphenyl) ethanol (p-HPEA-EDA), were lower in fully-irrigated trees than in trees under deficit irrigation or those that received complementary irrigation only. The concentrations of lignans (+)-1-acetoxipinoresinol and (+)-1-pinoresinol were unaffected by the irrigation regime. Volatile compounds, evaluated on the VOO head space, seemed to be more consistently influenced by the year rather than soil water availability

    Potential of the Oxidized Form of the Oleuropein Aglycon to Monitor the Oil Quality Evolution of Commercial Extra-Virgin Olive Oils

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    The quality of commercially available extra-virgin olive oils (VOOs) of different chemical compositions was evaluated as a function of storage (12 months), simulating market storage conditions, to find reliable and early markers of the virgin olive oil (VOOs) quality status in the market. By applying a D-optimal design using the Most Descriptive Compound (MDC) algorithm, 20 virgin olive oils were selected. The initial concentrations of oleic acid, hydrophilic phenols, and a-tocopherol in the 20 VOOs ranged from 58.2 to 80.5%, 186.7 to 1003.2 mg/kg, and 170.7-300.6 mg/kg, respectively. K-270, increment K, (E, E)-2.4-decadienal and (E)-2-decenal, and the oxidative form of the oleuropein aglycon (3,4-DHPEA-EA-OX) reflected the VOO quality status well, with 3,4-DHPEA-EA-OX being the most relevant and quick index for simple monitoring of the "extra-virgin" commercial shelf-life category. Its HPLC-DAD evaluation is easy because of the different wavelength absorbances of the oxidized and non-oxidized form (3,4-DHPEA-EA), respectively, at 347 and 278 nm

    Use of Dried Stoned Olive Pomace in the Feeding of Lactating Buffaloes: Effect on the Quantity and Quality of the Milk Produced

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    Dried stoned olive pomace (DSOP) was administered to dairy water buffaloes, and their productive performance and milk composition were analysed. Sixteen pluriparous lactating buffaloes were divided into two uniform groups (control and experimental), taking into consideration the following parameters: milk production (2,192 and 2,102 kg) and duration of lactation (254 and 252 d) of the previous year, distance from calving (51 and 43 d), milk production (9.71 and 10.18 kg/d), body condition score (BCS) (6.44 and 6.31) and weight (617 and 653 kg) at the beginning of the trial. Both diets had the same formulation: second cut alfalfa hay 20%, corn silage 42%, concentrate 38% but the two concentrates differed in their formulation, the experimental one contained 15.50% of DSOP as fed. The employed DSOP showed high amounts of secoiridoids, such as 3,4-dihydroxyphenylethanol (3,4-DHPEA) (1.2 g/kg DM), 3,4-dihydroxyphenylethanol-elenolic acid di-aldehyde (3,4-DHPEA-EDA) (12.6 g/kg DM), p-hydroxyphenylethanol-elenolic acid di-aldehyde (p-HPEA-EDA) (5.6 g/kg DM) and lignans, which are known to be powerful bioactive compounds. The control diet had an energy-protein content of 0.86 Milk FU/kg DM and 143.3 g/kg DM of crude protein, whereas the experimental diet of 0.87 Milk FU/kg DM and 146.6 g/kg DM of crude protein. Each animal of the two groups received 17 kg DM/d and each buffalo of the experimental group, by way of the concentrate, ingested 1.05 kg DM/d of DSOP. The trial lasted 40 days. No significant difference was found between the BCS (6.41 and 6.53), live weight (625.93 and 662.50 kg) and milk production (9.69 and 10.08 kg/d) of the two groups, as was the case for fat, protein, lactose, pH and coagulating parameters of the two milks. The milk fat of the experimental group had a significantly higher content of total tocopherols (10.45 vs 8.60 μg/g, p<0.01) and retinol (3.17 vs 2.54 μg/g, p<0.01). The content of the reactive substances with tiobarbituric acid (TBARs) was significantly lower in the milk fat of the experimental group (12.09 vs 15.05 μg MDA/g, p<0.01). The acid content of the milk fat of the experimental group had a significantly higher content (p<0.05) of C18:0 and of C18:3ω6. LC-MS/MS analysis showed the presence of 3,4-DHPEA (36.0 μg/L) in the milk of the DSOP-fed buffaloes, while other phenols were not found. DSOP, in the quantity utilized, can be used in the feeding of the lactating buffalo; the dietetic-nutritional characteristics of the milk are improved due to a greater contribution of tocopherols, retinol and the presence of hydroxytyrosol

    Impact of the malaxation temperature on the phenolic profile of cv. Cobrançosa olive oils and assessment of the related health claim

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    Phenolic compounds contribute to the bioactive properties of olive oil. However, olive oils can only support a health claim concerning the protection against oxidative stress depending on the polyphenolic concentration, requiring effective measures during extraction to preserve/enhance their concentrations. The effect of the malaxation temperature (22, 28 and 34 °C) on the phenolic profile was studied for industrially extracted cv. Cobrançosa oils. Higher malaxation temperatures decreased the contents of the majority of the chromatographically detected compounds (P<0.05, one-way ANOVA), enabling oils differentiation. This decreasing trend was observed for hydroxytyrosol and tyrosol bound forms, determinant for the health claim, which were also negatively affected by temperature, despite revealing that all the industrially extracted oils tested supported the health claim. The observed constant free to bound forms ratio showed that the temperature range tested had a minor effect on bound-forms hydrolysis, being both free and bound forms equally affected by temperature.The authors are grateful to the Foundation for Science andTechnology (FCT, Portugal) forfinancial support by national fundsFCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020), to REQUIMTE-LAQV (UIDB/50006/2020) and to BioTecNorteoperation (NORTE‐01‐0145‐FEDER‐000004) funded by the EuropeanRegional Development Fund under the scope of Norte2020‐Programa Operacional Regional do Norte. Ítala Marx acknowledges the Ph.D.research grant (SFRH/BD/137283/2018) provided by FCT. NunoRodrigues thanks the National funding by FCT- Foundation for Scienceand Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

    A Measure of Perceived Performance to Assess Resource Allocation

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s00500-015-1696-3Performance measurement is a key issue when a company is designing new strategies to improve resource allocation. This paper offers a new methodology inspired by classic importance-performance analysis (IPA) that provides a global index of importance versus performance for firms. This index compares two rankings of the same set of features regarding importance and performance, taking into account underperforming features. The marginal contribution of each feature to the proposed global index defines a set of iso-curves that represents an improvement in the IPA diagram. The defined index, together with the new version of the diagram, will enable the assessment of a firm's overall performance and, therefore, enhance decision making in the allocation of resources. The proposed methodology has been applied to a Taiwanese multi-format retailer and managerial perceptions of performance and importance are compared to assess the firm's overall performance.Peer ReviewedPostprint (author's final draft
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