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Background Prolamins are the endosperm storage proteins of cereal grains. Currently, the agri-food industry generates large quantities of by-products, among which are those generated from wet-milling, such as Gluten Meals (GM), dry-milling, such as the Distillers Dried Grains with Solubles (DDGS) and Brewer's Spent Grain (BSG). These by-products are important biopolymer sources such as prolamins. The prolamins have low nutritional value, however can be are useful for obtaining micro- and nanomaterials Scope and approach The main objective of this review was to make known the techniques of obtaining and its main applications in micro- and nanotechnology of prolamins obtained from cereal, and the purpose of this investigation was to promote the use of prolamins obtained from cereal by-products. Key findings and conclusions The prolamins can be obtained of by-products cereals and due to their economic importance and high productivity, the main cereals that generate these types of by-products are wheat and corn, in addition to sorghum, which is experiencing an increasing boom. The conformational structure of prolamins render them feasible for producing various micro- and nanomaterials, particles and fibers. These micro- and nanomaterials are of interest in the food industry and medicine for protection of bioactive compounds, pickering emulsions stabilized, drug delivery system and controlled release fertilizer. There is more evidence on nanomaterials that micromaterials that have been obtained from prolamins: from 2014 and up to date, around 247 investigations have been published dealing with the obtention of nanoparticles and nanofibers, of which only 2.0% corresponds to materials obtained from cereals by-products. Therefore, future prolamin research in nanotechnology from the by-products of cereals is necessary, with the purpose of increase added value and decreasing environmental contamination.

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.

Evaluating the biological potential of wheat grain cultivated in northwestern Mexico is important because it mainly varies according to the cultivar and production area. The aim of the present study was to evaluate ferulic acid (FA) bioaccessibility in breads supplemented with bioprocessed bran. Bran that was bioprocessed with xylanase enzyme (EB), yeast fermentation (FB), and a combination of both treatments (FEB) showed a higher total phenol content and antioxidant capacity compared with native bran (NB), and the majority of these components were found in a bound fraction. For NB and bioprocessed bran, FA was found at higher levels compared to the other hydroxycinnamic acids evaluated. Bioprocessing increased the free FA content six-fold compared to NB. The % bioaccessibility of FA in different breads increased in the following order: FEB

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 &plusmn, 0.42 mM TE/g, DPPH and 18.37 &plusmn, 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.

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.

At present, the development of natural polymeric microparticles is carried out to obtain release systems. Prolonged-release systems are a potential solution to avoid nitrogen (N) losses in agricultural fields. The aim of this study was to develop microspheres from wheat-gluten proteins soluble in ethanol 70% (v/v), to ascertain their characterization, and to study their potential application in agricultural fields. Soluble-protein extraction was performed with 1600 mL of ethanol 70% (v/v). Likewise, ethanolic solutions with protein concentrations of 0.5%, 1%, and 2% (w/v) are classified as non-Newtonian fluids with pseudoplastic behavior. Using the nanoprecipitation method, it was possible to develop urea-loaded microspheres with a diameter ranging from 900 nm–1.7 μm. The Fourier transform infrared spectroscopy (FTIR) test exhibited interaction through hydrogen bonds between carbonyls and amino groups from the urea and proteins. Also, the thermogravimetric analysis (TGA) test demonstrated thermal stability at 130°C. The release experiment showed that the microspheres achieved equilibrium when 88% of the urea was released. Finally, according to the empirical model of Ritger and Peppas, urea release is carried out through Fickian diffusion. We conclude that the microspheres could be applied in the fields and with this improve agricultural practices. Also, they could reduce the potential environmental pollution and developing a sustainable agriculture.