Edible coatings as osmotic dehydration pretreatment in nutrient-enhanced fruit or vegetable snacks development: A review

Edible coatings (ECs) are thin layers applied on food to protect it and improve quality. They are made from bio-based materials such as polysaccharides, proteins, lipids, or their composites. The incorporation of functional agents, such as bioactive compounds, vitamins, or antimicrobials into the EC, has been investigated to control the shelf life of many food products from horticulture ones to processed food. Osmotic dehydration (OD) as a mild technology may also positively impact the availability of innovative fruit snacks and consequently influence consumer health. Combination of the EC with the OD aims to remove water through the semipermeable membrane while limiting the transfer of solutes from the dehydrated tissue and in the opposite direction from the osmotic solution to the food. The development trend of the snack market is expanding, especially with health-promoting properties. Consumers pay increasing attention to quality of food and its beneficial effects on health. This review attempts to provide the advancement of recent studies on the application of the EC before the OD of different fresh or fresh-cut fruit and vegetables. A fundamental theory related to the methodology of creating the EC, their composition, and the influence on the physicochemical properties of products that are osmo-dehydrated to a medium water content or additionally dried to a low water content have been described. Efforts have been exerted to introduce hydrocolloids used in the production of the EC, including new sources of biopolymers such as agricultural waste and by-products. The perspectives of using ECs in the technology of producing pro-healthy snacks are emphasized.     

Interfacial charge transfer and photocatalytic activity in a reverse designed Bi2O3/TiO2 core-shell

In this study, the electronic and photocatalytic properties of core-shell heterojunctions photocatalysts with reversible configuration of TiO₂ and Bi₂O₃ layers were studied. The core-shell nanostructure, obtained by efficient control of the sol-gel polymerization and impregnation method of variable precursors of semiconductors, makes it possible to study selectively the role of the interfacial charge transfer in each configuration. The morphological, optical, and chemical composition of the core-shell nanostructures were characterized by high-resolution transmission electron microscopy, UV-visible spectroscopy and X-ray photoelectron spectroscopy. The results show the formation of homogenous TiO₂ anatase and Bi₂O₃ layers with a thickness of around 10 and 8 nm, respectively. The interfacial charge carrier dynamic was tracked using time resolved microwave conductivity and transition photocurrent density. The charge transfer, their density, and lifetime were found to rely on the layout layers in the core-shell nanostructure. In optimal core-shell design, Bi₂O₃ collects holes from TiO₂, leaving electrons free to react and increase by 5 times the photocatalytic efficiency toward H₂ generation. This study provides new insight into the importance of the design and elaboration of optimal heterojunction based on the photocatalyst system to improve the photocatalytic activity.     

Mechanical characterisation of three percutaneous vertebroplasty biomaterials

Percutanous vertebroplasty (PVP) is gaining popularity for the treatment of vertebral compression fractures. The need of obtaining low viscosity materials for injection through small bore needles and the necessity of visualising the fluid flow during injection have led users to the formulation of a number of ad-hoc recipes aimed at adapting PMMA cements for this use. Industry, on its part, has addressed these requirements by developing specific products for this application. This study aimed at providing a direct comparison of a wide range of mechanical properties between three commercially available biomaterials developed for PVP: two PMMA based materials, Osteopal V (Merck Biomaterial GMBH, Dermstedt, D) and Verterbroplastic (DePuy Acromed, Inc, MA, USA), and a Bis-GMA composite, Cortoss (Orthovita, PA, USA). Cortoss consistently exhibited higher values for compressive strength, bending modulus and shear strength to both Osteopal V and Vertebroplastic. The creep behaviour of Cortoss was also different from that of the two PMMA cements. PVP can take advantage from the development of new injectable biomaterials in response to the problems associated with the use of PMMA in a highly vascularised area such as the vertebral body. In addition careful modulation of the mechanical properties of the material has the potential to further improve the outcome of PVP, possibly reducing the risk of adjacent level fractures associated with the procedure.     

Life cycle assessment in buildings: State-of-the-art and simplified LCA methodology as a complement for building certification

The paper presents the state-of-the-art regarding the application of life cycle assessment (LCA) in the building sector, providing a list of existing tools, drivers and barriers, potential users and purposes of LCA studies in this sector. It also proposes a simplified LCA methodology and applies this to a case study focused on Spain. The thermal simulation tools considered in the Spanish building energy certification standards are analysed and complemented with a simplified LCA methodology for evaluating the impact of certain improvements to the building design. The simplified approach proposed allows global comparisons between the embodied energy and emissions of the building materials and the energy consumption and associated emissions at the use stage.The results reveal that embodied energy can represent more than 30% of the primary energy requirement during the life span of a single house of 222 m² with a garage for one car. The contribution of the building materials decreases if the house does not include a parking area, since this increases the heated surface percentage. Usually the top cause of energy consumption in residential building is heating, but the second is the building materials, which can represent more than 60% of the heating consumption.     

Antifungal Effect of Mexican Oregano (Lippia berlandieri Schauer) Essential Oil on a Wheat Flour-Based Medium

The antimicrobial activity of oregano has been attributed mainly to the presence of volatile compounds found in its essential oil (EO), mainly carvacrol and thymol. The search for antimicrobial activity of oregano EO with different concentrations of thymol and carvacrol, can lead to products with a wider range of applications. The aim of this work was to describe the in vitro antifungal effect of Mexican oregano (Lippia berlandieri Schauer) EO fractions on the growth of Aspergillus, Penicillium, and Rhizopus sp. The Mexican oregano EO fractions studied had different concentrations of carvacrol, which decreased from fraction 1 to 5 (81% to 23%), while thymol content increased from 3% to 64%. Fungal inhibition was evaluated on a wheat flour-based medium with EO fractions concentrations ranging from 50 to 200 mg/kg. Radial growth curves were fitted using the modified Gompertz model (R(2) (adj) = 0.989 ± 0.01). No significant differences (P > 0.05) were found with the different composition of the Mexican oregano EO fractions; nevertheless, fraction concentration presented significant (P < 0.05) mold inhibition as concentration increased. Rhizopus sp. (Rh18) showed a linear reduction on specific growth rate, on the maximum mold growth at the stationary phase, and an increase in the lag time as the concentration of the oregano EO increased; mold growth inhibition were achieved at 150 mg/kg in fractions 1 to 4, and at 100 mg/kg for fraction 5. Aspergillus sp. (As6) and Penicillium sp. (Pe36) were inhibited at 150 and 200 mg/kg, respectively. Results obtained suggest that Mexican oregano EO (Lippia berlandieri Schauer) compounds could be used as antimicrobial agents to prevent fungal growth in bakery products.     

Fully developed mixed convection flow of a nanofluid through an inclined channel filled with a porous medium

In this paper, the steady fully developed mixed convection flow of a nanofluid in a channel filled with a porous medium is presented. The walls of the channel are heated by a uniform heat flux and a constant flow rate is considered through the channel. The equations of the problem are made non-dimensional and are observed to depend on the dimensionless parameters, namely the mixed convection parameter λ, the Péclet number Pe, the inclination angle of the channel to the horizontal γ and the nanoparticle volume fraction ?. The effects of these parameters on the fluid and heat transfer characteristics are in detail discussed for three different nanofluids as Cu–water, Al₂O₃–water and TiO₂–water.     

Digital Image Analysis Applied to Tumor Cell Proliferation,Aggressiveness, and Migration-Related Protein Synthesis in Neuroblastoma 3D Models

Patient-derived cancer 3D models are a promising tool that will revolutionize personalized cancer therapy but that require previous knowledge of optimal cell growth conditions and the most advantageous parameters to evaluate biomimetic relevance and monitor therapy efficacy. This study aims to establish general guidelines on 3D model characterization phenomena, focusing on neuroblastoma. We generated gelatin-based scaffolds with different stiffness and performed SK-N-BE(2) and SH-SY5Y aggressive neuroblastoma cell cultures, also performing co-cultures with mouse stromal Schwann cell line (SW10). Model characterization by digital image analysis at different time points revealed that cell proliferation, vitronectin production, and migration-related gene expression depend on growing conditions and are specific to the tumor cell line. Morphometric data show that 3D in vitro models can help generate optimal patient-derived cancer models, by creating, identifying, and choosing patterns of clinically relevant artificial microenvironments to predict patient tumor cell behavior and therapeutic responses.     

Ductile/brittle PA6/PS system: Effect of carbon nanoplatelets-modified interface on performance

Addition of rigid PS to ductile PA6 can lead to higher toughness provided plastic deformation of PS is achieved. The current study deals with upgrading of this system by graphene, graphene oxide (GO), and GO with grafted polystyrene (GO-g-PS). Low amount of these carbon nanoplatelets can enhance performance of the PA/PS 90/10 system with the best-balanced properties achieved with GO-g-PS by unique combination of reinforcement with the favorable effect of the GO-g-PS-modified interface on plastic deformation of the PS phase causing higher impact resistance. Simultaneous linking of PA chains and hydrogen bonding causes “anchoring” of PS inclusions in the PA6 phase. This results in support of hydrostatic pressure evolution during loading and thus extensive yielding of PS. Another positive effect is reduction of pullout of in situ formed fibrous inclusions, which is different from rigid short-fiber composites. The study highlights high potential of GO modified with polymer chains to upgrade polymer systems via tailoring the interface.     

Spherical indentation of a transversely isotropic elastic half-space reinforced with a thin layer

The frictionless spherical indentation test is considered for a transversely isotropic elastic half-space reinforced with a thin layer whose flexural stiffness is negligible compared to its tensile stiffness. It is assumed that the deformation of the reinforcing layer can be treated as the generalized plane stress state. Closed-form analytical approximate equations for the maximum contact pressure, contact radius, and contact force are presented. The isotropic case is considered in detail.