Influence of Protective Colloids on Calcium Tartrate Stability and the Astringency Perception in a Red Wine.

Calcium tartrate instability in wines has been a neglected topic for many years. However, it seems that this problem is gaining prominence, and the industry welcomes inputs to address this issue. Among the alternatives that winemakers use for tartrate salt stabilization, the addition of authorized protective colloids is one of the best choices because they are easy to apply and have a low energetic cost. In the present study, the same red wine was treated with five different commercially available protective colloids in triplicate. The effectiveness of such colloids on calcium tartrate potential instability was estimated, in addition to their side effects on the phenolic composition of the treated wines and their astringency perception, as assessed by sensory analyses of the treated wine. The results show that, under these trial conditions, carboxymethylcellulose is the best choice for reducing the risk of calcium tartrate precipitation in wine. Moreover, the application of protective colloids to the wines had little effect on their color, phenolic composition, or evolution during one year of bottle storage. Finally, the addition of protective colloids did not impact the astringency intensity, but it influenced the dynamic perception of astringency according to the temporal dominance of sensation analysis.

Dataset of Schinus terebinthifolius essential oil microencapsulated by spray-drying.

Schinus terebinthifolius Raddi has been extensively studied due to its antioxidant, anti-inflammatory and antibiotic properties. Recently, its seeds have been tested against some insect pests as an insecticide, repellent and antifungal agent. Microencapsulation by spray-drying is widely used in the food and drug industries, as well as in the microencapsulation of essential oils, since it protects the oils against several effects, such as oxidation and thermal degradation, thus optimising its use. The aim was to microencapsulate S. terebinthifolius essential oil by spray-drying maltodextrin and arabic gum as encapsulating agents and SiO2 as a colloidal adjuvant. The morphology of the microcapsules was analysed by scanning electron microscopy (SEM), which evidenced mainly regular spherical-shaped particles with sizes between 5 and 10 µm. The thermal stability was studied by thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), and the microcapsules were stable at temperatures up to 200°C. The microencapsulating agents and the spray-drying technique produced microcapsules capable of protecting the essential oil against external effects, such as thermal degradation.

A Ferrofluid with High Specific Absorption Rate Prepared in a Single Step Using a Biopolymer.

An exhaustive characterization of the physicochemical properties of gum arabic (GA)-coated Fe3O4 magnetic nanoparticles was conducted in this work. These nanoparticles were obtained via the in-situ coprecipitation method (a fast single-step method) in two GA:Fe ratios, 10:1 and 20:1, respectively. Several experimental techniques were applied in the characterization process, all of them described below. Using Transmission Electron Microcopy images, they were shown to have spherical-like morphology with 11 nm diameter. The Fourier Transform Infrared spectra confirmed the attachment of the GA on the surface of the magnetic nanoparticles (MNPs), providing good colloidal stability from pH 7 to 8. The thickness of the coatings (1.7 nm and 1.1 nm) was determined using thermogravimetric measurements. A high specific absorption rate and superparamagnetic properties were determined using alternant and static magnetic fields, respectively. The GA-coated MNPs were non-cytotoxic, according to tests on HT-29 human intestine cells. Additionally, HT-29 cells were exposed to magnetic fluid hyperthermia at 530 kHz, and the induction of cell death by the magnetic field, due to the heating of GA-coated MNP, was observed.

Eco-friendly synthesis and photocatalytic application of flowers-like ZnO structures using Arabic and Karaya Gums.

Flowers-like ZnO structures were synthesized using Arabic Gum (AGZnO) or Karaya Gum (KGZnO). The AGZnO and KGZnO were characterized by X-ray diffractometry, Fourier Transformed Infrared, Scanning Electron Microscopy, Photoluminescence, nitrogen adsorption/desorption and diffuse reflectance techniques. The materials were tested in the discoloration of Methylene Blue (MB) dye under visible light and scavenger studies were also performed. The toxicity of the MB irradiated was investigated in bioassays with Artemia salina. The structural characterization demonstrated the formation of hexagonal ZnO. All samples presented flower-like morphology with presence of mesopores identified by BET method. The optical properties indicated band gap of 2.99 (AGZnO) and 2.76 eV (KGZnO), and emission in violet, blue and green emissions also were observed. The KGZnO demonstrated better photocatalytic performance than the AGZnO, and scavenger studies indicated that OH radicals are the main species involved in the degradation of the pollutant model. The photodiscoloration of MB solution did not demonstrate toxicity. Therefore, KGZnO is a promising material for photocatalysis application.

Arabic gum-based composite hydrogels reinforced with eucalyptus and pinus residues for controlled phosphorus release.

Arabic gum-based composite hydrogels reinforced with eucalyptus and pinus residues were synthesized via free-radical reaction aiming to controlled phosphorus release. All hydrogels were characterized by swelling kinetics (SK), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-Ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical assays (MA). The water and solute transports through the hydrophilic three-dimensional networks of the hydrogels occur preferably by diffusion processes and macromolecular relaxation. Hemicellulose, lignin and cellulose fibers contained in eucalyptus and pinus residues affected the crosslinking density, crystalline structure, and water/solute diffusion due to reduction of free hydroxyl and amine groups in the hydrogel networks. Hence, the eucalyptus and pinus residues improved the mechanical and thermal resistances of the composite hydrogels. Finally, the Arabic gum-based hydrogel and Arabic gum-based composite hydrogels reinforced with eucalyptus and pinus residues demonstrated to be excellent alternatives for the controlled phosphorus release in agricultural nutrient-poor soils.

Improved green coffee oil antioxidant activity for cosmetical purpose by spray drying microencapsulation

AbstractThe oil extracted by cold pressing unroasted coffee beans, known as green coffee oil, has been widely used for cosmetic purposes. The objective of this work was to prepare and characterize microcapsules containing green coffee oil and to verify its antioxidant activity under the effect of light, heat and oxygen. The encapsulating material was arabic gum and the microcapsules were obtained by spray drying an oil-in-water emulsion containing green coffee oil. The characterization of the microcapsules was performed by laser diffraction, scanning electron microscopy, differential scanning calorimetry and the antioxidant activity. The antioxidant activity was determined by a modified active oxygen method with light irradiation, heating and oxygen flux. The microparticles were effectively produced by the proposed spray drying method, which resulted in green coffee oil loads of 10 and 30%. The morphological evaluation of microcapsules showed spherical shape with smooth and non-porous surfaces, demonstrating the adequacy of arabic gum as encapsulating material. Calorimetric analysis of individual components and microcapsules with 10 and 30% green coffee oil showed diminished degradation temperatures and enthalpy, suggesting a possible interaction between arabic gum and green coffee oil. The antioxidant activities for pure green coffee oil and its microcapsules with loads of 10 and 30% showed high activity when compared to the reference antioxidant alfa-tocopherol. Microcapsules containing 10 and 30% of oil showed 7-fold and 3-fold increase in antioxidant activity when compared to pure green coffee oil. The new method for antioxidant activity determination proposed here, which applies heat, light and oxygen simultaneously, suggests a high improvement in encapsulated green coffee oil when compared to this active alone. The results showed herein indicate a promising industrial application of this microencapsulated green coffee oil.

Production of grape juice powder obtained by freeze-drying after concentration by reverse osmosis

This study aimed to evaluate the freeze-drying process for obtaining grape juice powder by reverse osmosis using 50% grape juice pre-concentrated (28.5 °Brix) and 50% hydrocolloids (37.5% maltodextrin and 12.5% arabic gum). The morphology of the glassy food showed the absence of crystalline structure, which was the amorphous wall that protected the contents of the powder. The samples were stored in clear and dark containers at room temperature, evaluated for their physical (X-ray diffraction) for 65 days and chemical (polyphenol content) stability for 120 days. During the storage time in plastic vessels, samples remained physically stable (amorphous) and the phenolic concentration was constant, indicating the potentiality of this technique to obtain a stable product with a high concentration of phenolic compounds. Therefore, the freeze-drying process promoted the encapsulation of concentrated grape juice increasing its stability and shelf life, as well as proving to be an applicable process to food industry.

Aproveitamento do resíduo do despolpamento da jabuticaba (Myrciaria cauliflora) para obtenção de pigmento com propriedades funcionais / Utilization of the waste of the pulping of the jabuticaba (Myrciaria cauliflora) for obtaining a functional pigment

A jabuticaba é uma fruta originalmente brasileira e que começa a ser explorada comercialmente para produção de polpa congelada, geleia, licor, dentre outros produtos. O processamento da jabuticaba gera uma grande quantidade de resíduos, oriundos da casca e da semente, que normalmente são descartados em aterros, contribuindo para poluição ambiental. Todavia, esses resíduos são ótimas fontes de ingredientes funcionais, tais como antocianinas (pigmentos roxos) e elagitaninos, ambos potentes antioxidantes. Assim, o objetivo deste estudo foi extrair o pigmento do resíduo do despolpamento da jabuticaba e caracteriza-lo; estudar o processo de secagem por atomização do pigmento;caracterizar os pós obtidos, bem como sua propriedade antioxidante e estabilidade durante o armazenamento. Para tanto, a jabuticaba foi despolpada, e do resíduo (cascas e sementes) foi obtido um extrato aquoso, o qual foi caracterizado quanto ao teor de sólidos solúveis, pH, umidade, cinzas, proteínas, lipídeos, fibras, açúcares e acidez, e, em seguida, foi desidratado em spray-dryer com os agentes carreadores maltodextrina DE10 e goma arábica. [...] Os pós obtidos apresentaram valores altos para antocianinas, fenólicos totais e atividade antioxidante, mostrando o grande potencial do resíduo do despolpamento da jabuticaba para produção de um pigmento funcional. A presença do carreador foi efetiva para manter a estabilidade do pigmento durante a estocagem e quanto maior a sua concentração, maior a estabilidade do pigmento

The jabuticaba is originally a Brazilian fruit and begins to be exploited commercially for the production of frozen pulp, jelly, liquor, among oth er products. The processing of jabuticaba generates a lot of waste, from the peel and seeds, which are usually discarded in landfills, contributing to environmental pollution. However, these residues are good sources of functional ingredients, such as anthocyanins (purple pigments) and elagitannins, both potent antioxidants. The objective of this study was to extract the pigment from the pulping of jabuticaba's waste and characterized it, to study the process of spray drying the pigment; characterize the po wders, as well as its antioxidant properties and storage stability. To this aim, jabuticaba was pulped, and the residue (peel and seeds) was obtained from an aqueous extract, which was characterized as the soluble solids, pH, moisture, ash, protein, lipid, fiber, sugars and acidity, and then was dried in a spray-dryer with agents carriers of 10 maltodextrin and gum arabic. [...] The powders obtained showed high concentration of anthocyanins, phenolic compounds and antioxidant activity, showing the great potential of the residue of jabuticaba's waste for production of a functional pigment. The presence of the carrier was effective for maintaining stability of the pigment during storage and the higher the concentration, the greater the stability of the pigment