Nanoparticles of Betalain-Gelatin with Antioxidant Properties by Coaxial Electrospraying: Preparation and Characterization.

Betalains are bioactive compounds with attractive antioxidant properties for the food industry, endowing them with potential application in food coatings to maintain quality and extend shelf life. However, they have low stability to factors such as light, temperature, and humidity. An alternative to protect bioactive compounds is nanoencapsulation; one of the most used techniques to produce an encapsulation is coaxial electrospraying. In this research, the preparation and characterization of gelatin-betalain nanoparticles were carried out using the coaxial electrospray technique. Betalains were extracted from pitaya (Stenocereus thurberi) and encapsulated in gelatin. The obtained material was evaluated by SEM, FTIR, TGA, and DSC techniques and for its antioxidant capacity. By SEM, nanoparticles with spherical and monodisperse morphologies were observed, with betalain concentrations of 1 and 3% w/v and average diameters of 864 and 832 µm, respectively. By FTIR, the interaction between betalain and gelatin was observed through amino groups and hydrogen bonds. Likewise, the antioxidant activity of the betalains was maintained at the time of encapsulation, increasing the antioxidant activity as the concentration increased. The results of the DPPH, ABTS, and total phenols methods were 645.4592 µM T/g, 832.8863 ± 0.0110 µM T/g, and 59.8642 ± 0.0279 mg GAE/g for coaxial nanoparticles with 3% betalains, respectively. Therefore, the coaxial electrospray technique was useful for obtaining nanoparticles with good antioxidant properties, and due to the origin of its components and since the use of toxic solvents is not necessary in the technique, the material obtained can be considered food grade with potential application as a coating on functional foods.

Effect of a Prolonged-Release System of Urea on Nitrogen Losses and Microbial Population Changes in Two Types of Agricultural Soil.

Urea is the nitrogen-containing fertilizer most used in agricultural fields; however, the nutrient given by the urea is lost into the environment. The aim of this research was to determine the effect of two soil textures by applying a prolonged-release system of urea (PRSU) on the N losses. This research shows an important decrease of the nitrate and ammonium losses from 24.91 to 87.94%. Also, the microbiological population increases after the application of the PRSU. It was concluded that both soil textures presented the same loss-reduction pattern, where the N from the nitrates and ammonium was reduced in the leachates, increasing the quality of the soil and the microbial population in both soil textures after the PRSU application.

Antioxidant and Antimicrobial Effect of Biodegradable Films Containing Pitaya (Stenocereus thurberi) Extracts during the Refrigerated Storage of Fish.

This study focused on the quality loss inhibition of fish muscle during refrigerated storage. Two parallel experiments were carried out that were focused on the employment of pitaya (Stenocereus thurberi) extracts in biodegradable packing films. On the one hand, a pitaya-gelatin film was employed for hake (Merluccius merluccius) muscle storage. On the other hand, a pitaya-polylactic acid (PLA) film was used for Atlantic mackerel (Scomber scombrus) muscle storage. In both experiments, fish-packing systems were stored at 4 °C for 8 days. Quality loss was determined by lipid damage and microbial activity development. The presence of the pitaya extract led to an inhibitory effect (p < 0.05) on peroxide, fluorescent compound, and free fatty acid (FFA) values in the gelatin-hake system and to a lower (p < 0.05) formation of thiobarbituric acid reactive substances, fluorescent compounds, and FFAs in the PLA-mackerel system. Additionally, the inclusion of pitaya extracts in the packing films slowed down (p < 0.05) the growth of aerobes, anaerobes, psychrotrophs, and proteolytic bacteria in the case of the pitaya-gelatin films and of aerobes, anaerobes, and proteolytic bacteria in the case of pitaya-PLA films. The current preservative effects are explained on the basis of the preservative compound presence (betalains and phenolic compounds) in the pitaya extracts.

Use of Coffee Bean Bagasse Extracts in the Brewing of Craft Beers: Optimization and Antioxidant Capacity.

Coffee bean bagasse is one of the main by-products generated by industrial coffee production. This by-product is rich in bioactive compounds such as caffeine, caffeic and chlorogenic acid, and other phenols. The aims of this work are to optimize the extraction conditions of phenolic compounds present in coffee bean bagasse and incorporate them into stout-style craft beers, as well as to determine their effect on the phenol content and antioxidant capacity. The optimal conditions for extraction were 30% ethanol, 30 °C temperature, 17.5 mL of solvent per gram of dry sample, and 30 min of sonication time. These conditions presented a total phenol content of 115.42 ± 1.04 mg GAE/g dry weight (DW), in addition to an antioxidant capacity of 39.64 ± 2.65 µMol TE/g DW in DPPH• and 55.51 ± 6.66 µMol TE/g DW for FRAP. Caffeine, caffeic and chlorogenic acids, and other minor compounds were quantified using HPLC-DAD. The coffee bean bagasse extracts were added to the stout craft beer and increased the concentration of phenolic compounds and antioxidant capacity of the beer. This work is the first report of the use of this by-product added to beers.

Effect of Ultrafiltration of Pitaya Extract (Stenocereus thurberi) on Its Phytochemical Content, Antioxidant Capacity, and UPLC-DAD-MS Profile.

Stenocereus thurberi is an endemic species in northwestern Mexico. It produces colorful fruits called pitayas that have an edible pulp. They have phytochemical compounds associated with biological activities. Ultrafiltration is a widely used method for the clarification of fruit juices and the recovery of phytochemicals. However, its effect has not been extensively studied in extracts. Therefore, the objective of this work is to study the effect of the ultrafiltration of pitaya extract (Stenocereus thurberi) on its phytochemical content, antioxidant capacity, and identification of phenolic compounds by UPLC-DAD-MS, providing greater knowledge about the pitaya. In this study, two extracts were analyzed, the unclarified extract (UE) and the clarified extract (CE). The antioxidant capacity was higher in the CE with 15.93 ± 0.42 mM TE/g, DPPH and 18.37 ± 0.016 mM TE/g, ABTS. The UPLC-MS analysis indicated the decrease in phenolic compounds in the CE and the presence of gallic acid and resorcinol, compounds that had not been identified in other species of Stenocereus spp. The correlation analysis indicated that all the phytochemicals present in the pitaya contribute significantly to the antioxidant capacity. The ultrafiltration process could be a viable option to improve the biological activity of the natural extracts.

Preparation and Characterization of Quercetin-Loaded Zein Nanoparticles by Electrospraying and Study of In Vitro Bioavailability.

Quercetin is a hydrophobic flavonoid with high antioxidant activity. However, for biological applications, the bioavailability of quercetin is low due to physiological barriers. For this reason, an alternative is the protection of quercetin in matrices of biopolymers as zein. The objective of this work was to prepare and characterize quercetin-loaded zein nanoparticles by electrospraying and its study of in vitro bioavailability. The physicochemical parameters such as viscosity, density, and electrical conductivity of zein solutions showed a dependence of the ethanol concentration. In addition, rheological parameters demonstrated that solutions of zein in aqueous ethanol present Newtonian behavior, rebounding in the formation of nanoparticles by electrospraying, providing spherical, homogeneous, and compact morphologies, mainly at a concentration of 80% (v/v) of ethanol and of 5% (w/v) of zein. The size and shape of quercetin-loaded zein nanoparticles were studied by transmission electron microscopy (TEM), observing that it was entrapped, distributed throughout the nanoparticle of zein. Analysis by Fourier transform-infrared (FT-IR) of zein nanoparticles loaded with quercetin revealed interactions via hydrogen bonds. The efficacy of zein nanoparticles to entrap quercetin was particularly high for all quercetin concentration evaluated in this work (87.9 ± 1.5% to 93.0 ± 2.6%). The in vitro gastrointestinal release of trapped quercetin after 240 min was 79.1%, while that for free quercetin was 99.2%. The in vitro bioavailability was higher for trapped quercetin (5.9%) compared to free quercetin (1.9%), than of gastrointestinal digestion. It is concluded, that the electrospraying technique made possible the obtention of quercitin-loaded zein nanoparticles increasing their bioavailability. PRACTICAL APPLICATION: This type of nanosystems can be used in the food and pharmaceutical industry. Quercetin-loaded zein nanoparticles for its improvement compared to free quercetin can be used to decrease the prevalence of chronic degenerative diseases by increasing of the bioavailability of quercetin in the bloodstream. Other application can be as an antioxidant system in functional foods or oils to increase shelf life.

Gallic Acid-Loaded Zein Nanoparticles by Electrospraying Process.

Currently, electrospraying is a novel process for obtaining the nanoparticles from biopolymers. Zein nanoparticles have been obtained by this method and used to protect both hydrophilic and hydrophobic antioxidant molecules from environmental factors. The objective of this work was to prepare and characterize gallic acid-loaded zein nanoparticles obtained by the electrospraying process to provide protection to gallic acid from environmental factors. Thus, it was related to the concentration of gallic acid in physicochemical and rheological properties of the electrosprayed solution, and also to equipment parameters, such as voltage, flow rate, and distance of the collector in morphology, and particle size. The physicochemical properties showed a relationship in the formation of a Taylor cone, in which at a low concentration of gallic acid (1% w/v), low viscosity (0.00464 ± 0.00001 Pa·s), and density (0.886 ± 0.00002 g/cm3 ), as well as high electrical conductivity (369 ± 4.3 µs/cm), forms a stable cone-jet mode. The rheological properties and the Power Law model of the gallic acid-zein electrosprayed solution demonstrated Newtonian behavior (n = 1). The morphology and size of the particle were dependent on the concentration of gallic acid. Electrosprayed parameters with high voltage (15 kV), low flow rate (0.1 mL/hr), and short distance (10 cm) exhibited a smaller diameter and spherical morphology. FT-IR showed interaction in the gallic acid-loaded zein nanoparticle by hydrogen bonds. Therefore, the electrospraying process is a feasible technique for obtaining gallic acid-loaded zein nanoparticles and providing potential protection to gallic acid from environmental factors.

Zein-polysaccharide nanoparticles as matrices for antioxidant compounds: A strategy for prevention of chronic degenerative diseases.

Oxidative Stress (OS) produces the formation of free radicals and other reactive oxygen and nitrogen species that are intimately involved in many diseases, especially Chronic Degenerative Diseases (CDD) such as cancer, diabetes, cardiovascular diseases, and obesity, among others. Thus, reactive compounds need to be quenched by antioxidants. The problems of these compounds include that they are susceptible to degradation, have low bioavailability, and can lose their bioactivity in the gastroIntestinal tract. Therefore, an alternative is encapsulation. Zein is a protein used in nanotechnology as a polymer matrix because it can encapsulate different compounds such as antioxidants to provide stability and control of the release. The disadvantage of zein as a delivery vehicle is that it is limited by the low stability of aggregation when suspended in water, in addition to the conditions of acid pH or that higher ionic strength tends to destabilize. To reduce these limitations, the incorporation of polysaccharides as a second polymer matrix can provide stability in zein nanoparticles. In this review, we discuss OS as a source of CDD, the role of antioxidants in the prevention of these diseases, and the preparation, characterization, and application of antioxidant-zein-polysaccharide particles as delivery systems as well as possible mechanisms to control CDD.