An Overview of the Bioactive Profile and Food Applications of This Versatile Crop Adapted to Arid Lands

Funding Information: This research was funded by national funding by the FCT, Foundation for Science and Technology, through the individual research grant (2020.04441.BD) of C.R. This work was supported by the Associate Laboratory for Green Chemistry—LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020), and by the Mechanical Engineering and Resource Sustainability Center—MEtRICs, which is financed by national funds from FCT/MCTES (UIDB/04077/2020 and UIDP/04077/2020). This work also received funds from FCT/MCTES through project ERANETMED/0001/2017—MediOpuntia (Portugal). The project MediOpuntia also received support through ERANETMED-MediOpuntia from Science and Technology Development Funding authority (STDF—Egypt), Ministry of Education, Universities and Research (MIUR—Italy), and Ministry of National Education, Vocational Training, Higher Education and Scientific Research (MENFPESRS—Morocco). Publisher Copyright: © 2023 by the authors.Opuntia spp. are crops well adapted to adverse environments and have great economic potential. Their constituents, including fruits, cladodes, and flowers, have a high nutritional value and are rich in value-added compounds. Cladodes have an appreciable content in dietary fiber, as well as bioactive compounds such as kaempferol, quercetin, and isorhamnetin. Fruits are a major source of bioactive compounds such as phenolic acids and vitamin C. The seeds are mainly composed of unsaturated fatty acids and vitamin E. The flowers are also rich in phenolic compounds. Therefore, in addition to their traditional uses, the different plant fractions can be processed to meet multiple applications in the food industry. Several bakery products have been developed with the incorporation of cladode flour. Pectin and mucilage obtained from cladodes can act as edible films and coatings. Fruits, fruit extracts, and fruit by-products have been mixed into food products, increasing their antioxidant capacity and extending their shelf life. Betalains, obtained from fruits, can be used as food colorants and demonstrate promising applications as a sensor in food packaging. This work reviews the most valuable components of the different fractions of this plant and emphasizes its most recent food applications, demonstrating its outstanding value.publishersversionpublishe

Etude des propriétés physico-chimiques et électroniques de matériaux ferroélectriques sous forme de céramiques et de films minces en vue d'applications radiofréquences et microondes

L objectif du présent travail est de concevoir, réaliser et optimiser des matériaux accordables pour des applications en électronique à hautes fréquences. Le composant le plus simple permettant de mettre à profit cette étude est le condensateur accordable avec une tension continue qui peut être ensuite intégrée dans des dispositifs microondes accordables ou reconfigurables. Le condensteur peut être en couches minces ou en céramique. Pour réaliser de tels composants, on doit utiliser des matériaux présentant de faible pertes diélectriques, une permitivité élevée, une accordabilité importante et une bonne stabilité de la fréquence de résonance avec la température. Pour cela, nous avons mené une étude sur des matériaux ferroélectriques classiques et relaxeurs afin, d une part d optimiser les conditions de synthèse, et d autre part d améliorer leurs propriétés électriques pour des applications radiofréquences et microondes. Nous avons étudié des matériaux ferroélectriques de phase pérovskite. Il s agit du titane de baryum et de strontium (BST) qui est un ferroélectrique classique, du titane de baryum et de zircone (BZT) qui selon sa composition peut être classique ou relaxeur et des dérivées du BZT obtenues par substitution au niveau des sites pérovskites a et b respectivement par du bismuth et par du zinc-niobium. Nous avons aussi synthétisé et caractérisé des matériaux de phase pyrochlore de formule Bi1.5ZnNb1.5O7. Ces études vont de l élaboration de tous ces matériaux sous forme de céramiques et de couches minces, suivies de caractérisations physico-chimiques, structurales, diélectriques et ferroélectriques dans une large gamme de fréquences et de températures.The main objective of this work is to design, implement and optimize tunable materials for electronic applications at high frequencies. The easiest component to build on this study is the tunable capacitor with a voltage which can then be integrated into microwave devices such as tunable or reconfigurable resonators, filters, antennas...etc. The capacitor can be either thin film or ceramic-based. To produce such components we must use materials which must have low dielectric loss, high dielectric permittivity, high tunability and stability of the resonant frequency of the capacitor with the temperature. For this, we conducted a detailed study of classical and relaxor ferroelectric materials in order, firstly to optimize the synthesis conditions, and secondly to improve their electrical properties for radiofrequencies and microwave applications. We have studied ferroelectric materials with perovskite phase, namely barium titanate strontium (BST) which is a classical ferroelectric and barium zirconium (BZT) which according to its composition can be a classical ferroelectric or relaxor ferroelectric and the derivatives of BaZr0.1Ti0.9O3 obtained by substituting bismuth and zinc-niobium respectively at A and B sites of the perovskite phase. We also synthesized and characterized the pyrochlore phase materials of bismuth zinc niobate, with composition of Bi1.5ZnNb1.5O7. The studies we have done range from the development of these materials in the form of ceramics and thin films, followed by characterizations to determine their physico-chemical properties, structural dielectric and ferroelectric in a range wide of frequencies and temperature.CALAIS-BU Sciences (621932101) / SudocSudocFranceF

Effect of the RF-power and annealing on the structural, optical, morphological and electrical properties of RF-sputtered V

Thin films of vanadium oxide were deposited on glass substrates by the radio frequency reactive sputtering from a high purity metallic vanadium target (99.7%) with a diameter of 10 cm. The reactive sputtering was carried out in an argon-oxygen gas mixture containing 10% of O2 and 90% of Ar. The films were deposited at different RF powers (150 W, 200 W, 250 W and 300 W) for a fixed deposition time of 150 min. X-ray diffractograms showed that the deposited thin films crystallized in an orthorhombic V2O5 phase. It was found that the crystallite size varies with the RF power and is maximized using 300 W as an RF power. Scanning Electron Microscopy and Raman scattering analyzes have confirmed the formation of V2O5 thin films. In addition, optical transmittance measurements were performed using a Shimadzu UV-PC spectrophotometer in the 220–2000 nm range. It was observed that the optical band gap of the films decreases with increasing the RF power. Electrical resistivity was found to decrease with increasing the RF power from 150 to 250 W, and then it increases

Investigation of the appropriate phase change temperatures for an enhanced passive indoor thermal regulation in a semi-arid climate: Tunable PCM case

Researchers in the building industry are becoming increasingly interested in phase change materials (PCM). As these PCMs might provide passive temperature adjustment, this will aid in lowering the energy consumption of Heating, Ventilation, and Air-Conditioning (HVAC) devices. To prevent leakage during phase change, an enclosure is needed when installing PCMs in buildings. The need to assess the passive thermal regulation of the PCMs at different melting temperature is necessary, so that we can get a sense of how much energy will be saved for this passive thermal regulation method. Hence, this paper will evaluate and identify the optimum phase change transition temperatures during the whole year for wall composition with tunable PCM in a semi-arid climate. Thus, the main objective of this study is to assess the indoor air temperature fluctuation reduction and the PCM activation while suggesting an appropriate phase change transition temperature that can be beneficial in the whole year and very practical. The results reveal a good passive temperature regulation during the summer period

Subsurface Water Retention Technology Promotes Drought Stress Tolerance in Field-Grown Tomato

Agricultural activities depend heavily on irrigation in arid and semi-arid climates, which are one of the most water-limited areas, reducing agricultural productivity. As the climate changes, the lack of precipitation is expected to aggravate in these areas, requiring careful management of water use. Subsurface water retention technology (SWRT) may hold promise as a management tool to save water use and improve crop drought resistance. In this context, the effect of SWRT on tomato yield, growth, physiology, and biochemical characteristics, as well as soil characteristics under two regimes of water (100% field capacity (FC) and 50% FC) in open field conditions, was investigated. The results here suggest that drought affected tomato performance. Nevertheless, SWRT application significantly increased tomato yield (38%), chlorophyll fluorescence (3%), gas exchange (39%), and chlorophyll total content (49%), as well as soil fertility characteristics, with significant increases in organic matter (23%) and assimilable phosphorus contents (25%) compared with the control. Furthermore, it resulted in a significant reduction in enzymatic antioxidant activities and polyphenol and significant improvement in fruit quality by increasing protein content. This technique should be used as a valuable strategy to save irrigation water and mitigate the negative effects of water deficiency on tomato plants in arid and semi-arid regions

Subsurface Water Retention Technology Promotes Drought Stress Tolerance in Field-Grown Tomato

Agricultural activities depend heavily on irrigation in arid and semi-arid climates, which are one of the most water-limited areas, reducing agricultural productivity. As the climate changes, the lack of precipitation is expected to aggravate in these areas, requiring careful management of water use. Subsurface water retention technology (SWRT) may hold promise as a management tool to save water use and improve crop drought resistance. In this context, the effect of SWRT on tomato yield, growth, physiology, and biochemical characteristics, as well as soil characteristics under two regimes of water (100% field capacity (FC) and 50% FC) in open field conditions, was investigated. The results here suggest that drought affected tomato performance. Nevertheless, SWRT application significantly increased tomato yield (38%), chlorophyll fluorescence (3%), gas exchange (39%), and chlorophyll total content (49%), as well as soil fertility characteristics, with significant increases in organic matter (23%) and assimilable phosphorus contents (25%) compared with the control. Furthermore, it resulted in a significant reduction in enzymatic antioxidant activities and polyphenol and significant improvement in fruit quality by increasing protein content. This technique should be used as a valuable strategy to save irrigation water and mitigate the negative effects of water deficiency on tomato plants in arid and semi-arid regions

Effect of RF power on the structural and optical properties of RF-sputtered ZnO thin films

ZnO thin films were deposited by reactive cathodic radio-frequency (RF) sputtering from a pure Zn target in a gas mixture of 30% O2 and 70% Ar and at different RF powers. The structural properties of the as-deposited thin films were studied by X-ray diffraction (XRD). The optical properties (especially the refractive index, absorption coefficient and optical band gap) were investigated by optical transmission measurements in the ultraviolet-visible-near Infrared wavelength range. The XRD patterns showed that the as-deposited ZnO thin films are polycrystalline. The crystallite size varied with RF power reaching a maximum at 200 W. These results were correlated with X-ray refectometry measurements which revealed a minimum in the film density at 200 W. The deposition rate of these films varied from 2.53 to 5.27 nm/min depending on the RF-power, with a maximum at 200 W. On the other hand, the optical band gap Eg was quasi-constant (about 3.28 eV) when the RF power was increased from 100 to 300 W

Fast room temperature solution-​phase approach for selective synthesis of nanostructured Cu(OH)​2, Cu2O and CuO

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