Pulsed electric fields as a green technology for the extraction of bioactive compounds from thinned peach by-products

Thinned fruits are agricultural by-products which nowadays have few economic or environmental benefits. However, previous studies have revealed that these immature fruits have a large amount of antioxidant compounds. The aim of this study was to evaluate whether pulsed electric fields (PEF) might be a suitable green technology for enhancing the extraction of phenols, flavonoids and antioxidant compounds from fresh thinned peaches, thus reducing the use of methanol. Moreover, response surface methodology has been used to determine the optimal PEF treatment conditions, observing that the solvent is the main factor. The highest amounts of bioactive compounds were extracted using 80% methanol and no PEF. Methanol combined with PEF produced a negative effect on the extraction yield. However, the use of water as a solvent increased the amount of total bioactive compounds and individual phenols (chlorogenic acid, coumaric acid and neochlorogenic acid). Thus, PEF-assisted extraction of bioactive compounds from thinned peach fruits using water as a solvent is an alternative to conventional extraction methods which require dried products, large amounts of organic solvents and long extraction times

HYDROGEN PRODUCED BY SOLAR ENERGY AND THEIR USE AS CLEAN FUEL FOR POWER GENERATION IN A COMBINED CYCLE POWER PLANT

The solar energy is one of the most promising energy sources expected for the future, due at their huge potential and the wide availability around the world. However, nowadays this important source of energy is not being harnessed or even addressed in their full potential. According to the last statements, it is important to develop solar energy conversion systems of high efficiency, as well as spreading its use in other forms besides the traditional systems of electric power generation or heating systems. For this reason, in this paper, it is explored the production of hydrogen through solar energy utilization, and the later electrical energy production by burning the produced hydrogen in a combined cycle power plant. The process was modelled for 3 MWe of electricity generation, and using the organic Rankine cycle. The main process for producing hydrogen from water using solar energy is based on a two steps redox thermochemical cycle, which has a theoretical conversion efficiencies of 54% at 1600 K. It is expected that this paper could contributed to the development of ways to enable a better integration of the solar energy with the current electricity generation technologies, as well as to incentive the use of the hydrogen as a clean fuel

Effect of modified atmosphere packaging (MAP) and UC-C irradiation on postharvest quality of red raspberries

Red raspberries (Rubus idaeus L.) are highly appreciated by consumers. However, their postharvest shelf life scarcely exceeds 5 d under the refrigeration temperatures usually applied during commercialization, due to their high susceptibility to dehydration, softening and rot incidence. Thus, the objective of this study was to investigate the ability of UV-C radiation (UV1: 2 kJ m-2 and UV2: 4 kJ m-2 ), passive modified atmosphere packaging (MAP) with transmission rates (TR) for O2 and CO2 of 1805 mL d-1 and 1570 mL d-1 (MAP1), and 902 mL d-1 and 785 mL d-1 (MAP2), respectively, and the combination of both technologies to prolong raspberries’ shelf life at 6¿ C. Their influence on respiration, physicochemical parameters, and microbiological and nutritional quality was assessed during 12 d of storage. The combination of 4 kJ m-2 UV-C radiation and a packaging film with O2 and CO2 transmission rates of 902 mL d-1 and 785 mL d-1, respectively, produced a synergistic effect against rot development, delaying senescence of the fruit. The UV2MAP2 and MAP2 samples only showed 1.66% rot incidence after 8 d of storage. The UV2MAP2 samples also had higher bioactive content (1.76 g kg-1 of gallic acid equivalents (GAE), 1.08 g kg-1 of catechin equivalents (CE) and 0.32 g kg-1 of cyanidin 3-O-glucoside equivalents (CGE)) than the control samples at the end of their shelf life. Moreover, the mass loss was minimal (0.56%), and fruit color and firmness were maintained during shelf life. However, the rest of the batches were not suitable for commercialization after 4 d due to excessive mold development. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

ORGANIC RANKINE CYCLE ASSOCIATED WITH AN ABSORPTION CHILLER FOR BIOMASS APPLICATIONS

The main goal of this work is to develop a calculation process, based on the second law of thermodynamic, for evaluating the potential of a small Organic Rankine Cycle (ORC) cogeneration (electrical and cooling power) plant using biomass as fuel. Two different configurations and several organic working fluids are presented and assessed. A mathematical model has been developed to find thermodynamically suitable fluids for ORC in biomass cogeneration plants. The main results show that, the family of alkylbenzenes has higher exergetic efficiencies found to be around 16% almost 5 percent higher efficiency than the cycles that use siloxanes as working fluids; in spite of their lower cooling power capacity. The results demonstrate that the cycle efficiency is more dependent on the thermodynamic properties of the working fluids than on the system configuration

Origin of ferroelectricity in the multiferroic barium fluorides BaMF4

We present a first principles study of the series of multiferroic barium fluorides with the composition BaMF4, where M is Mn, Fe, Co, or Ni. We discuss trends in the structural, electronic, and magnetic properties, and we show that the ferroelectricity in these systems results from the "freezing in" of a single unstable polar phonon mode. In contrast to the case of the standard perovskite ferroelectrics, this structural distortion is not accompanied by charge transfer between cations and anions. Thus, the ferroelectric instability in the multiferroic barium fluorides arises solely due to size effects and the special geometrical constraints of the underlying crystal structure.Comment: 8 pages, 6 figures, 3 table

Comparison of efficacy and modes of action of two high-potential biocontrol Bacillus strains and commercial biocontrol products against Botrytis cinerea in table grapes

In table grapes (cv. Thomson Seedless), the antifungal activity against Botrytis cinerea was further analysed and compared between two high potential bacterial biological control agent (BCA) strains, Bacillus velezensis BUZ-14 and B. ginsengihumi S38. Two commercial biocontrol products (BPs), served as standards of comparison, Amylo-X (R) and Serenade Max (R), also based on Bacillus BCA strains. The main mode of action quantified for all the strains was antibiosis due to hydrosoluble and volatile metabolites and their combinations. The BUZ-14 strain was the most active BCA strain, demonstrating significant disease reduction exceeding 60 % when used in the culture form grown in 863 medium, including living cells (LCs) and cell-free supernatant (CFS). Both BPs exhibited significantly reduced efficacy of their CFS fraction (< 10 %) compared with that of the two BCA strains, confirming their high antibiosis potential. The novel methodology allowed us to demonstrate the significant effect of the BCA culture medium on volatilome (VOC) antagonist efficacy. The S38 strain achieved the highest disease reduction (90 %) owing to the greatest production of VOCs in the richest MOLP (Medium Optimum Lipopetide Production) culture medium, whereas grape juice was the least favourable medium for VOC efficacy for both bacterial strains (BUZ14 and S38). The overall poor activity of living Bacillus cells in all the BCA and BPs tested is discussed based on the low capacity of the BCA strains to grow in the berry. Then, the presence of living cells is also discussed with the possibility that these cells are not required in field applications of such BCA strains in this genus. Moreover, different environmental suboptimal conditions, including temperature (22 and 27 degrees C) and relative humidity (RH) (100 and 85-95 %), were tested, and BUZ-14 exhibited the highest Botrytis reduction at both temperatures and RH values. However, no significant differences were observed between temperatures or RH values for the same BCA. Further studies in vineyard conditions and applications, such as biofumigation or active packaging, will be performed to confirm the new findings reported in this investigation

Observation and theoretical description of the pure Fano-effect in the valence-band photo-emission of ferromagnets

The pure Fano-effect in angle-integrated valence-band photo-emission of ferromagnets has been observed for the first time. A contribution of the intrinsic spin polarization to the spin polarization of the photo-electrons has been avoided by an appropriate choice of the experimental parameters. The theoretical description of the resulting spectra reveals a complete analogy to the Fano-effect observed before for paramagnetic transition metals. While the theoretical photo-current and spin difference spectra are found in good quantitative agreement with experiment in the case of Fe and Co only a qualitative agreement could be achieved in the case of Ni by calculations on the basis of plain local spin density approximation (LSDA). Agreement with experimental data could be improved in this case in a very substantial way by a treatment of correlation effects on the basis of dynamical mean field theory (DMFT).Comment: 11 pages, 3 figures accepted by PR

Correlação entre peroxidase e severidade da deterioração fisiológica pós-colheita em raízes de mandioca.

A comercialização da mandioca é limitada por causa da deterioração fisiológica pós-colheita (DFPC) que se manifesta nas raízes dentro de 24 a 48 horas causando perdas de qualidade e valor comercial. O presente trabalho objetivou avaliar a correlação entre a atividade da peroxidase e a severidade da deterioração fisiológica em raízes de mandioca tolerantes e susceptíveis à DFPC ao longo do armazenamento. Raízes de mandioca provenientes de duas áreas experimentais (COOPAMIDO e UFRB) foram avaliadas no dia da colheita e aos 02, 05 e 10 dias após, em cinco repetições/genótipo/dia. A DFPC foi avaliada visualmente conforme a severidade (%) dos sintomas distribuídos na fatia das raízes em três cortes transversais (proximal, mediano e distal) ao longo da raiz inteira. As notas da DFPC foram transformadas em valores da área abaixo da curva de progresso da deterioração (AACPD). A análise da AACPD gerou quatro grupos, dos quais foram selecionados nove genótipos para extração e determinação da atividade da enzima peroxidase nos mesmos dias de avaliação visual da DFPC. Houve aumento da atividade da peroxidase ao longo do período de armazenamento, apresentando alta correlação positiva (> 80%) com a severidade dos sintomas de DFPC. Os resultados deste estudo sugerem que a peroxidase esteja envolvida no processo de deterioração fisiológica pós-colheita das raízes de mandioca dos genótipos avaliados, sendo um potencial indicador a ser utilizado no melhoramento da cultura para a identificação e geração de genótipos mais tolerantes à DFPC

Deflections in Magnet Fringe Fields

A transverse multipole expansion is derived, including the longitudinal components necessarily present in regions of varying magnetic field profile. It can be used for exact numerical orbit following through the fringe field regions of magnets whose end designs introduce no extraneous components, {\it i.e.} fields not required to be present by Maxwell's equations. Analytic evaluations of the deflections are obtained in various approximations. Mainly emphasized is a ``straight-line approximation'', in which particle orbits are treated as straight lines through the fringe field regions. This approximation leads to a readily-evaluated figure of merit, the ratio of r.m.s. end deflection to nominal body deflection, that can be used to determine whether or not a fringe field can be neglected. Deflections in ``critical'' cases (e.g. near intersection regions) are analysed in the same approximation.Comment: To be published in Physical Review

Correlação entre deterioração fisiológica pós-colheita e características agronômicas em mandioca.

O conhecimento das associações entre as características produtivas da mandioca (Manihot esculenta Crantz) pode auxiliar os programas de melhoramento genético a praticarem a seleção indireta. Isto é especialmente válido para características de difícil mensuração, como é o caso da deterioração fisiológica pós-colheita (DFPC). De modo geral, as correlações possuem causas genéticas pelo fato de alguns genes afetarem simultaneamente duas características, positiva ou negativamente. Neste sentido, o objetivo desse trabalho foi estimar as correlações fenotípicas entre DFPC e atributos agronômicos