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This work provides the first description of the synthesis and characterization of water-soluble chitosan (Cs) derivatives based on the conjugation of both diethylaminoethyl (DEAE) and catechol groups onto the Cs backbone (Cs-DC) in order to obtain a Cs derivative with antioxidant and antimicrobial properties. The degree of substitution [DS (%)] was 35.46% for DEAE and 2.53% for catechol, determined by spectroscopy. Changes in the molecular packing due to the incorporation of both pendant groups were described by X-ray diffraction and thermogravimetric analysis. For Cs, the crystallinity index was 59.46% and the maximum decomposition rate appeared at 309.3 °C, while for Cs-DC, the values corresponded to 16.98% and 236.4 °C, respectively. The incorporation of DEAE and catechol groups also increases the solubility of the polymer at pH > 7 without harming the antimicrobial activity displayed by the unmodified polymer. The catecholic derivatives increase the radical scavenging activity in terms of the half-maximum effective concentration (EC). An EC of 1.20 μg/mL was found for neat hydrocaffeic acid (HCA) solution, while for chitosan-catechol (Cs-Ca) and Cs-DC solutions, concentrations equivalent to free HCA of 0.33 and 0.41 μg/mL were required, respectively. Cell culture results show that all Cs derivatives have low cytotoxicity, and Cs-DC showed the ability to reduce the activity of reactive oxygen species by 40% at concentrations as low as 4 μg/mL. Polymeric nanoparticles of Cs derivatives with a hydrodynamic diameter (D) of around 200 nm, unimodal size distributions, and a negative ζ-potential were obtained by ionotropic gelation and coated with hyaluronic acid in aqueous suspension, providing the multifunctional nanoparticles with higher stability and a narrower size distribution., This work was funded by the Spanish Ministry of Science and Innovation (PID2020-114086RB-100). F.J.C.-L. acknowledges financial support from CONACyT (México) through the scholarship ‘Apoyo para estancias postdoctorales en el extranjero vinculadas a la consolidación de grupos de investigación y fortalecimiento del Posgrado nacional’. M.R.A. and B.V.-L. are members of the SusPlast platform from CSIC. This research work was performed in the framework of the Nanomedicine CSIC HUB (ref 202180E048). The authors thank R.A.R. from (ICTP), CSIC, for assistance in the biological experiments

In the present study, a culture of

Extracellular vesicles (EVs) are implicated in several biological conditions, including bone metabolism disturbances in breast cancer patients (BCPs). These disorders hinder the adjustment of nutrition interventions due to changes in bone mineral density (BMD). The biophysical properties of EVs (e.g., size or electrostatic repulsion) affect their cellular uptake, however, their clinical relevance is unclear. In this study, we aimed to investigate the association between the biophysical properties of the plasma-derived EVs and BMDs in BCPs who received an individualized nutrition intervention during the first six months of antineoplastic treatment. As part of the nutritional assessment before and after the intervention, body composition including bone densitometry and plasma samples were obtained. In 16 BCPs, EVs were isolated using ExoQuick® and their biophysical properties were analyzed using light-scattering techniques. We found that the average hydrodynamic diameter of large EVs was associated with femoral neck bone mineral content, lumbar spine BMD, and neoplasms’ molecular subtypes. These results provide evidence that EVs play a role in BCPs’ bone disorders and suggest that the biophysical properties of EVs may serve as potential nutritional biomarkers. Further studies are needed to evaluate EVs’ biophysical properties as potential nutritional biomarkers in a clinical context.

A nutritional intervention promotes the loss of body and visceral fat while maintaining muscle mass in breast cancer patients. Extracellular vesicles (EVs) and their characteristics can be potential biomarkers of disease. Here, we explore the changes in the Zeta potential of EVs; the content of miRNA-30, miRNA-145, and miRNA-155; and their association with body composition and biomarkers of metabolic risk in breast cancer patients, before and 6 months after a nutritional intervention. Clinicopathological data (HER2neu, estrogen receptor, and Ki67), anthropometric and body composition data, and plasma samples were available from a previous study. Plasma EVs were isolated and characterized in 16 patients. The expression of miRNA-30, miRNA-145, and miRNA-155 was analyzed. The Zeta potential was associated with HER2neu (β = 2.1; p = 0.00), Ki67 (β = −1.39; p = 0.007), estrogen positive (β = 1.57; p = 0.01), weight (β = −0.09; p = 0.00), and visceral fat (β = 0.004; p = 0.00). miRNA-30 was associated with LDL (β = −0.012; p = 0.01) and HDL (β = −0.02; p = 0.05). miRNA-155 was associated with visceral fat (β = −0.0007; p = 0.05) and Ki67 (β = −0.47; p = 0.04). Our results reveal significant associations between the expression of miRNA-30 and miRNA-155 and the Zeta potential of the EVs with biomarkers of metabolic risk and disease prognosis in women with breast cancer; particularly, the Zeta potential of EVs can be a new biomarker sensitive to changes in the nutritional status and breast cancer progression.

The fungus

The consumption of cricket (Acheta domesticus, AD) has recently increased due to its high nutritional and bioactive compound contents. However, limited studies have explored the beneficial effects of AD consumption. Therefore, we aimed to evaluate the protective effect of a diet supplemented with AD flour on obesity control and its complications in an in vivo model. The chemical profiling of the AD showed an important protein content, chitin, and polyunsaturated fatty acids contents. For the in vivo study, a high-fructose and saturated fat diet (HFFD) was supplemented with AD (4% and 8%). The 8% AD supplementation reduced body weight gain (19%) and serum triglycerides (37%) in HFFD-fed rats. These benefits were related to a greater lipid excretion in feces (97%) and the partial inhibition of pancreatic lipase in vitro by the aqueous extract and the hydrolyzed proteins obtained from AD. Additionally, the 8% AD supplementation improved insulin resistance measured by the HOMA index (61%). Thus, 8% AD supplementation to HFFD-fed rats was effective in preventing obesity, dyslipidemia, and insulin resistance. PRACTICAL APPLICATIONS: Obesity is a risk factor for developing insulin resistance and dyslipidemia. Therefore, there is an increasing interest in consuming foods rich in bioactive compounds as therapeutic alternatives for managing the development of obesity and its complications. Edible insects, such as crickets, are attractive for treating obesity due to their content of protein, fiber, and polyunsaturated fatty acids. Studies have explored the effect of glycosaminoglycan (GAG)-enriched extracts from the cricket Gryllus bimaculatus against obesity. However, GAG content in crickets is low, and crickets are commonly consumed whole instead of extracts. The cricket Acheta domesticus (AD) is among the most rearing cricket species as it is easy to farm and has a better flavor. However, limited studies have explored the beneficial effects of AD consumption. This study demonstrates that AD prevents obesity and ameliorates dyslipidemia and insulin resistance. Therefore, AD is a valuable entomotherapeutic strategy to reduce the comorbidities associated with diet-induced obesity.

The Diels–Alder reaction is recognized to generate highly selective and regiospecific cycloadducts. In this study, we carried out a rheological and kinetic study of N-furfuryl chitosan hydrogels based on the Diels–Alder click reaction with different poly(ethylene)glycol-maleimide derivatives in dilute aqueous acidic solutions. It was possible to prepare clear and transparent hydrogels with excellent mechanical properties. Applying the Winter and Chambon criterion the gel times were estimated at different temperatures, and the activation energy was calculated. The higher the temperature of gelation, the higher the reaction rate. The crosslinking density and the elastic properties seem to be controlled by the diffusion of the polymer segments, rather than by the kinetics of the reaction. An increase in the concentration of any of the two functional groups is accompanied by a higher crosslinking density regardless maleimide:furan molar ratio. The hydrogel showed an improvement in their mechanical properties as the temperature increases up to 70 °C. Above that, there is a drop in G’ values indicating that there is a process opposing to the Diels–Alder reaction, most likely the retro-Diels–Alder.

Rhizoclonium riparium is a filamentous green seaweed widely distributed along the coast of Sinaloa. Unfortunately, this seaweed remains unexploited despite having been described as an important source of bioactive molecules. Guided fractionation based on solvent partitioning is a common approach to screen for new natural bioactive compounds. By applying accurate design and interpretation among partition stages, this technique should permit an improvement in the bioactive response of extracts. Thus, the phytochemical composition and bioactivity of R. riparium fractions (FM methanol, FH hexane) obtained from acetone crude extracts (ACE) and sub-fractions from FM (FM1ethylacetate and FM2 water) by solvent partition were assessed. Chlorophyll and carotenoid content decreased during the partition process. The highest antioxidant activity of FM1, as assessed with the DPPH (2,2-diphenyl-1-picrylhydrazyl) test (501.39 Trolox equivalent antioxidant capacity or TEAC), was explained by the high total flavonoid (TFC) and phenol content (TPC). Moreover, a high flavonoid content led to the highest antioxidant activity being observed in FM, as assessed by ABTS·+(2, 2′-azinobis [3-ethylbenzthiazoline]-6-sulphonic acid) reduction (449.59 TEAC). Apart from FM2, the remaining fractions exhibited a strong antimutagenic activity at 0.015 mg per plate (> 40%); FM1 showed the highest antimutagenic bioactivity in both tested bacterial strains (90.4% and 88% for strains TA98 and TA100) of Salmonella typhimurium. Results showed that bioassay-guided fractionation exerted a selective effect on the phytochemical profile that enhanced the antioxidant and antimutagenic activity of the extracts of R. riparium.

El cultivo de olivo sustenta una poderosa industria cuyos principales productos son aceite y aceituna de mesa. El proceso de extracción del aceite de oliva deja un subproducto sólido conocido como orujo. Este residuo es una pasta húmeda compuesta principalmente por pulpa de aceitunas y sus semillas, que puede ser considerado un desecho con alto potencial contaminante. Por otra parte, el orujo puede ser utilizado como materia prima para la obtención de compuestos bioactivos. En este sentido, se caracterizó químicamente el desecho sólido de la extracción de aceite de olivo de la región de Caborca, Sonora. De resultados del análisis proximal se encontró que el orujo está constituido principalmente de grasas (17-19 %) y carbohidratos (13.8 %). El contenido de fenoles totales del orujo varió entre 44.7 a 46.4 mg EAC/g. El perfil de ácidos grasos del orujo resulto similar al observado en pasta de olivo usada como referencia. En general, el orujo mantiene los componentes de la pasta de olivo de donde proviene, por lo que puede ser utilizado como materia prima para la obtención de compuestos bioactivos y otras sustancias de interés comercial

El quitosano es un polisacárido natural que ha sido utilizado frecuentemente en el desarrollo de distintos materiales, debido a sus excepcionales propiedades fisicoquímicas y biológicas. Las nanopartículas de quitosano son generalmente producidas por estrategias denominadas de construcción (del inglés “bottom up”), donde el ensamblado polimérico es promovido por distintas interacciones moleculares. Sin embargo, un grupo de estrategias llamadas de deconstrucción (del inglés “top-down”) basadas en la fragmentación de estructuras macroscópicas, han generado un gran interés recientemente como alternativa para la obtención de nanomateriales. El presente trabajo hace una revisión bibliográfica de los resultados obtenidos por distintas investigaciones sobre la producción de sistemas de nanopartículas basadas en quitosano durante las últimas décadas. Las evidencias demostraron que las nanopartículas de quitosano juegan un papel preponderante en la investigación de los nanomateriales poliméricos con aplicaciones biomédicas y farmacéuticas, debido a la gran diversidad de métodos de obtención existentes que determinan las propiedades de los materiales, tales como tamaño de partícula, capacidad de incorporación y liberación de compuestos bioactivos, carga superficial, mucoadhesividad, entre otras.

Los arabinoxilanos (AX) son polisacáridos no amiláceos presentes en varios tejidos de cereales. Estos polisacáridos tienen la capacidad de formar geles covalentes mediante el acoplamiento oxidativo del ácido ferúlico por acción de agentes generadores de radicales libres. La capacidad gelificante de los AX depende de las características estructurales del polisacárido, por lo que el conocimiento de estas y su efecto en las propiedades del gel es esencial para crear una comprensión profunda sobre la naturaleza de estos geles. El contenido de proteína en AX es una de estas características estructurales, cuyo impacto en la gelificación del polisacárido y en las propiedades del gel no ha sido investigado a profundidad. Hasta el momento, no se conoce cómo es que la proteína se encuentra unida al AX. Esta revisión presenta investigaciones realizadas sobre la asociación arabinoxilano-proteína y la relación de la fracción proteica con la capacidad gelificante del polisacárido, así como de la posible unión covalente en dicha asociación.

Arabinoxylans (AX) microspheres with different insulin/AX mass ratio were prepared by formation of phenoxy radical issued from the ferulic acid by enzymatic oxidation (entrapped in situ of insulin). Phenolic acid content and FT-IR spectrum of unloaded and insulin-loaded AX microspheres revealed that the phenoxy radical issued from the ferulic acid by enzymatic oxidation did not interact covalently with insulin. The microspheres showed a spherical shape, smooth surface and an average diameter of particles of 320 μm. In vitro control release found that AX microspheres minimized the insulin loss in the upper GI tract, retaining high percentage (~75%) of insulin in its matrix. The stability of the secondary structure of insulin was studied by dichroism circular (CD). The CD spectra of insulin released from AX microspheres did not change according to the insulin/AX mass ratio of the microsphere. Significant hypoglycemic effects with improved insulin-relative bioavailability tested on an in vivo murine model revealed the efficacy of these enzymatically cross-linked arabinoxylans microspheres as a new oral insulin carrier.

In vivo evaluation of arabinoxylans (AX) microspheres showed to protect insulin from degradation in the upper gastrointestinal tract and carrier insulin to colon. Insulin-loaded AX microspheres (50 UI/kg) decreased blood glucose level by 39% in diabetic rats with a maximum effect at 18 h post-administration, indicating that insulin remains bioactive. The continuous administration (4 days) of insulin-loaded AX microspheres improved the polyuria and increased the production of short-chain fatty acids, as well as Bifidobacterium and Bacteroides in diabetic rats compared to untreated diabetic rats. AX microspheres are a potential microbiota-activated carrier for colon-specific drug delivery and could be useful as a complementary treatment for diabetes.

The objective of the present study is to evaluate the effect of individual and combined coatings of chitosan (0.008 g&middot, mL&minus, 1) and carnauba wax (0.1 g&middot, 1) with oregano essential oil (OEO, 0.08 g&middot, 1) to reduce dehydration and microbial decay of fresh cucumbers stored at 10 &deg, C. Chitosan-OEO-wax films showed the lowest water vapor transmission rate (0.141 g&middot, m&minus, 2&middot, h&minus, 1), compared to single chitosan films (0.257 g&middot, 1). While chitosan-OEO films completely inhibited the in vitro growth of Alternaria alternata and reduced the growth of Salmonella Typhimurium, Escherichia coli O157:H7, mesophilic bacteria, and fungi isolated from decayed cucumbers. Besides, the infrared analysis of chitosan-OEO-wax films showed shifts in O&ndash, H and N&ndash, H absorption bands, indicating possible hydrogen bonding between the components. Wax and wax-OEO were the most effective coatings to prevent weight loss in cucumbers during 15 days of storage at 10 &deg, C, while the most effective antimicrobial treatments were chitosan and chitosan-OEO. Therefore, these results showed that carnauba wax and carnauba wax-OEO coatings were the most effective in weight loss, whereas chitosan and chitosan-OEO were the most effective to reduce the microbial load of the treated fresh cucumber.

This work aimed to design a synthetic route under mild conditions allowing the main chitosan chain to be grafted with β-cyclodextrin (β-CD) and poly(N-isopropyl acrylamide) (PNIPAm), at C2 and C6 positions, respectively. For this reason, the regioselectivity of proposed reactions is an important factor to be considered. β-CD is an oligosaccharide with a cyclic structure capable of forming inclusion complexes with hydrophobic molecules. Grafting β-CD onto the chitosan backbone by reductive N-alkylation at C2 position was carried out. With this purpose, the previous preparation of β-CD monoaldehyde was required. PNIPAm is a thermosensitive polymer with a transition temperature near 33 °C. To regioselectively anchor poly(N-isopropyl acrylamide) chains onto chitosan at C6 position, it was required to attach at the C6 position of chitosan an alkyl group for the subsequent grafting of PNIPAm-N3 by means of copper-catalyzed azide-alkyne cycloaddition click reaction. To guarantee the regioselectivity of the functionalization of chitosan with a C6 terminal alkyne, its oxyalkylation with glycidyl propargyl ether in a solvent composed of LiOH/KOH/urea was used. The structure of all derivatives was confirmed by FT-IR and 1H-NMR spectroscopy.

Essential oils (EO) have been studied as a possible substitute of fungicides. EO have been loaded in polymeric nanoparticles to prevent their degradation and enhance antifungal activity. In this work was to prepared chitosan nanoparticles with Schinus molle EO by ionotropic gelation. The bionanocomposites were characterized by scanning electronic microscopy (SEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). The antifungal activity was evaluated in different growth stages of A. parasiticus (spore germination, radial growth and spore viability) and the effect in aflatoxin production was analyzed by using affinity chromatography columns from VICAM. DLS results showed that the Np-CS and Np-CS-SEO diameters were 361.9 ± 31.4 and 516.9 ± 45.4 nm, respectively. According to SEM, the NPs presented spherical shape and the zeta potential was slightly decreased when Schinus molle EO was incorporated. The Np-CS-SEO (62.5–500 μg mL−1) showed a high inhibition (>80%) on spore germination of A. parasiticus at 12 h of incubation, while, radial growth was not inhibited for these NPs. At a concentration of 500 μg mL−1, Np-CS-SEO inhibited up to 59% the aflatoxin production. Depending on concentration, the Np-CS-SEO can be considered as an alternative to control A. parasiticus.

The materials produced by the supercritical CO drying have outstanding properties that allow the incorporation of molecules in their porous structure. In this context, dried chitosan nanoparticles including β-lactoglobulin were obtained. First, the nanoparticles in water suspension were produced by ionotropic gelation incorporating the protein with high loading efficiency. Later, solvent exchange and CO supercritical drying procedures were performed. The physicochemical characteristics and structural properties were determined, demonstrating a stable porous structure in the dried materials and corroborating the presence of the protein after the drying. The CO supercritical dried chitosan nanoparticles can be effectively resuspended in acidic aqueous medium remaining in the nanoscale with minimum effect on the loading parameters. The release of the β-lactoglobulin was highly influenced by the pH, reaching around 40% under acidic conditions in ten hours. The obtained results demonstrate the possibility to apply these chitosan materials as a controlled release material., The authors want to acknowledge the financial support of CONACYT through the Project CB-2011-01-169626 and the fellowship DC2013-256 for FJCL. Similarly, it is highly appreciated the valuable input of the Biomaterials Research Group of the ICTP and the technical staff of the Biopolymers Research Group of CIAD.

In this study, particles of chitosan-carrageenan (Cs-Crg) and chitosan-carrageenan-lysozyme (CS-Crg-LZ) were synthesized by ionic complexation. The particles were analyzed by atomic force microscopy, dynamic light scattering and FT-IR, and the percentage of association of lysozyme was determined. The biological activity of the particles was evaluated by viability assays of Aspergillus parasiticus spores and cytotoxicity in ARPE-19 cells. The effect on subcellular structures was analyzed by fluorescence microscopy. The addition of lysozyme reduced the size of the particles. The size and Z potential of the synthesized particles were 725±5.5 and 250±8.1 nm and 28.7±1.0 and 21.6±0.8 mV for CS-Crg and CS-Crg-LZ, respectively. CS-Crg-LZ and CS-Crg particles exhibited a higher (p

Pectobacterium carotovorum causes soft rot in plant food due to its ability to synthesize exoenzymes, and secrete polymeric substances to form biofilm; in addition, this aggregated form of bacteria creates resistance during disinfection. However, the biofilm formation process and composition of P. carotovorum is still uncharacterized, which is important to design more efficient disinfection procedures. Among the actual disinfection trends, the use of plant compounds has deserved plenty of attention; being carvacrol, a monoterpene constituent of oregano essential oil that is known to reduce biofilm formation of many bacteria. Therefore, the objective of this study was to evaluate the effect of carvacrol against biofilm development of P. carotovorum, EPS composition, bacterial surface charge, adhesion potential and motility. Minimal planktonic inhibitory and bactericidal concentrations of carvacrol were 2.66 and 3.99 mM; whereas, concentrations of 1.33 and 3.99 mM were needed to inhibit and eradicate biofilm, respectively. Carvacrol at 0.66 mM was chosen as the concentration to evaluate its effect on EPS secretion, motility and surface physicochemical characteristics without affecting the viability of planktonic cells. It was shown that carvacrol at this concentration decreased bacterial surface charge (−2.15 mV), adhesion potential (−1.5 mJ/m2) and swimming motility of P. carotovorum (48.2 mm) compared with untreated bacteria. In addition, polysaccharides were the main components of the biofilm matrix of P. carotovorum, whose synthesis was inhibited by the presence of carvacrol. These results demonstrated that carvacrol could be effective against P. carotovorum biofilm formation and eradication, reducing adhesion, motility and synthesis of polysaccharides.

Recent studies have demonstrated that the micro and nanoparticles of chitosan (CS) have an in vitro antifungal effect against filamentous fungus that are of importance in food. This study was made to evaluate the antifungal activity of chitosan nanoparticles, pepper tree essential oil (PEO), and chitosan biocomposites loaded with pepper tree essential oil (CS-PEO), on the in vitro growth of Colletotrichum gloeosporioides. The particles were obtained by nanoprecipitation and the size and superficial charge (Z potential) were evaluated using dynamic light dispersion analysis (DLS). The mutagenic potential and the acute toxicity were also evaluated. The effect on the radial growth, spore’s germination, viability, and damage to the membrane´s integrity, were determined. The effect on the kinetic growth parameters was also determined. Results showed that the CS and CS-PEO particles diameter was 341.2 ± 12.40 and 355.3 ± 25.3 mm, respectively. In vitro assays showed both nanoparticles with a high inhibition potential on C. gloeosporioides, and low mutagenicity and toxicity. At a concentration of 0.160 mg/mL, the CS-PEO biocomposite presented a greater (P

This study aimed to investigate the effect of arabinoxylans (AX) partial de-esterification with feruloyl esterase on the polysaccharide conformational behavior, topographical features, and antioxidant activity. After enzyme treatment, the ferulic acid (FA) content in AX was reduced from 7.30 to 5.48 µg FA/mg polysaccharide, and the molecule registered a small reduction in radius of gyration (RG), hydrodynamic radius (Rh), characteristic ratio (C∞), and persistence length (q). A slight decrease in α and a small increase in K constants in the Mark–Houwink–Sakurada equation for partially de-esterified AX (FAX) suggested a reduction in molecule structural rigidity and a more expanded coil conformation, respectively, in relation to AX. Fourier transform infrared spectroscopy spectra of AX and FAX presented a pattern characteristic for this polysaccharide. Atomic force microscopy topographic analysis of FAX showed a more regular surface without larger hollows in relation to AX. The antioxidant activity of FAX, compared to AX, was reduced by 30 and 41% using both 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS+) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) methods, respectively. These results suggest that feruloyl esterase treatment of AX could offer a strategy to tailor AX chains conformation, morphological features, and antioxidant activity, impacting the development of advanced biomaterials for biomedical and pharmaceutical applications.

In this research, sorghum procyanidins (PCs) and procyanidin B1 (PB1) were encapsulated in gelatin (Gel) to form nanoparticles as a strategy to maintain their stability and bioactivity and for possible applications as inhibitors of metalloproteinases (MMPs) of the gelatinase type. Encapsulation was carried out by adding either PCs or PB1 to an aqueous solution of A- or B-type Gel (GelA or GelB) at different concentrations and pH. Under this procedure, the nanoparticles PCs–GelA, PCs–GelB, PB1–GelA, and PB1–GelB were synthesized and subsequently characterized by experimental and computational methods. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that all types of nanoparticles had sizes in the range of 22–138 nm and tended to adopt an approximately spherical morphology with a smooth surface, and they were immersed in a Gel matrix. Spectral analysis indicated that the nanoparticles were synthesized by establishing hydrogen bonds and hydrophobic interactions between Gel and the PCs or PB1. Study of simulated gastrointestinal digestion suggested that PCs were not released from the Gel nanoparticles, and they maintained their morphology (SEM analysis) and antioxidant activity determined by Trolox-equivalent antioxidant capacity (TEAC) assay. Computational characterization carried out through molecular docking studies of PB1 with Gel or (pro-)metalloproteinase-2 [(pro-)MMP-2], as a model representative of the PCs, showed very favorable binding energies (around −5.0 kcal/mol) provided by hydrogen bonds, van der Waals interactions, and desolvation. Additionally, it was found that PB1 could act as a selective inhibitor of (pro-)MMP-2.

This study evaluated the effect of grape stems extracts on motility, surface energy and adhesion of L. monocytogenes to stainless steel and polypropylene surfaces. Stem extracts from Red Globe grapes showed a higher content of total phenolics than Carignan stems. Moreover, both extracts reduced adhesion of Listeria to stainless steel (0.77-2.22 log CFU cm-2) and polypropylene (0.71-2.38 log CFU cm-2) and completely inhibited bacterial motility at 4.5 and 5 mg mL-1 of Red Globe and Carignan extracts, respectively. Similarly, both extracts affected the surface energy of bacteria and modified the adhesion potential of L. monocytogenes to both surfaces. Otherwise, caffeic, ferulic and gallic acids, catechin and rutin, presented in both extracts, reduced adhesion of L. monocytogenes to stainless steel (0.39-2.04 log CFU cm-2) at 10 mM. In conclusion, Red Globe and Carignan grape stem extracts inhibited adhesion of L. monocytogenes to stainless steel and polypropylene surfaces by inhibiting motility and modifying its adhesion potential.

Pectins are linear macromolecules with carboxylate and methoxylate groups. That may serve as coagulant-flocculant agents. At the same time it is expected that carboxylate groups act as a chelating agent and favor the entrapment of heavy metals. In this paper nopal pectin was tested to treat synthetic waste water (SWW) contaminated with metallic ions. First of all, it was extracted and characterized by FT-IR and NMR. Its molecular weight was approached by viscosimetry. Zeta potential measurements were done to determine the surface charge of the macromolecule and its ability to remove of metallic ions (Ca 2+ , Cu 2+ , Zn 2+ , Cr 3+ , Ni 2+ , Pb 2+ and Cd 2+ ). After its complete characterization, the ideal dose for the separation was obtained from experiments of consecutive additions of pectin in to a SWW. Finally, the solid and the supernatant were recovered and analyzed by MP-AES and SEM-EDS analyzes, it was determined that a dose of 0.019 mg/mL, removed to 99% of all metallic ions.

Background Arabinoxylans (AX) are polysaccharides constituted by a backbone of xyloses with arabinose substituents ester-linked to ferulic acid (FA). The arabinose to xylose ratio (A/X) in AX may vary from 0.3 to 1.1. AX form covalent gels by cross-linking of FA but physical interactions between AX chains also contribute to the network formation. The objective of this study was to investigate the rheological and microstructural characteristics of gels based on AX enzymatically modified in A/X. Results Tailored AX presented A/X ranging from 0.68 to 0.51 and formed covalent gels. Dimers of FA content and elasticity (G’) increased from 0.31 to 0.39 g kg−1 AX and from 106 to 164 Pa when the A/X in the polysaccharide decreased from 0.68 to 0.51. Atomic Force Microscopy (AFM) images of AX gels showed a sponge-like microstructure at A/X = 0.68 while at lower values, gels presented a more compact microstructure. Scanning electron microscopy (SEM) analysis of AX gels show an arrangement of different morphology, passing from an imperfect honeycomb (A/X = 0.68) to a flakes-like microstructure (A/X = 0.51). Conclusion Lower A/X values favor the aggregation of AX chains resulting in an increase in di-FA content which improve the rheological and microstructural characteristics of the gel formed.

Antioxidant, anticarcinogenic, and antimicrobial properties have been reported for ferulic acid (FA), therefore, its application interests both food and agriculture research. FA was immobilized in different chitosan (CS) matrices, physicochemicaly characterized and the effect on Aspergillus parasiticus ecological parameters evaluated. Nanoparticles (Nparticles), microparticles (Mparticles) and microcapsules (Mcapsules) of 35–40 nm, 30–40 μm, and 20 μm, respectively were obtained; FA incorporation in matrices affected their morphology, physicochemical properties, and their fungistatic effect. The effect of the particles was dependent on the matrix exposed. Nparticles and Mparticles showed high FA immobilization efficiency as well as a good fungistatic effect against A. parasiticus: Radial growth at 168 h was 28.46 ± 1.01 and 28.84 ± 1.36 and the inhibition of spore germination at 30 h was 57.44 ± 0.22 and 55.74 ± 2.19, for Nparticles and Mparticles, respectively compared with control cultures. Abnormalities in mycelium, hyphae, and spores morphology were observed, as well as low sporulation due particle interaction with the fungus.

Herein are reported the production and characteristics of chitosan nanoparticles that go through supercritical CO2 drying. First, chitosan nanoparticles in aqueous colloidal suspension were produced by ionic crosslinking with sodium tripolyphosphate. The produced nanoparticles have a surface charge (ζ-potential) of +27 mV and an average diameter of approximately 100 nm, measured by dynamic light scattering and field emission-scanning electron microscopy observations. The liquid phase of the nanoparticle suspension was replaced successively with ethanol and supercritical CO2 to produce dried chitosan nanoparticles finally. The main characteristics of the obtained nanoparticles were determined by diverse analytical techniques. Infrared spectroscopy, solid-state 13C nuclear magnetic resonance and X-ray diffraction studies were performed to explore possible physicochemical changes induced by the drying procedure. Also, the thermal stability of the dry chitosan nanoparticles was determined by thermogravimetric assay and dynamic scanning calorimetry. Structural properties were analyzed and compared with lyophilized nanoparticles finding that the supercritically dried chitosan nanoparticles have a surface area an order of magnitude higher. Microscopy images showed that the supercritically dried chitosan nanoparticles have a porous conglomerated structure, suggesting that there is particle aggregation through the drying process. Notwithstanding, the dry chitosan nanoparticles resuspended in the dilute acid medium readily; microscopy observations showed that the size of the resuspended particles remains in the nanoscale range. The proposed procedure is able to furnish dried chitosan nanoparticles with structural characteristics and functional properties that are appealing for their use in diverse applications.

espanolSe determino la composicion bioquimica de algas verdes (Ulva expansa, Caulerpa sertularioides, Rhizoclonium riparium, Codium isabelae), rojas (Spyridia filamentosa, Gracilaria vermiculophylla) y parda ( Padina durvillaei) recolectadas en diferentes lagunas tropicales en la costa del Pacifico en Sinaloa, Mexico. El contenido de proteinas fue mas alto en C. sertularioides, S. filamentosa y G. vermiculophylla (10–12%), seguido de R. riparium, P. durvillaei y U. expansa (8%, 6% y 4%, respectivamente). El contenido de lipidos se encontro en el intervalo de 0.3–1.5%, con el valor mas alto encontrado en R. riparium. El contenido mas alto del extracto libre de nitrogeno (i.e., carbohidratos) (69%) y el valor mas bajo de cenizas (25%) se encontro en P. durvillaei. El contenido de acidos grasos poliinsaturados (AGPI) se encontro en el intervalo del 5% al 45%, con los valores mas altos en R. riparium (45%), C. sertularioides (39%) y P. durvillaei (23%). Las algas rojas mostraron el mayor valor de colesterol+dehidrocolesterol (>90%), mientras que las algas verdes mostraron el mayor contenido de β-sitosterol (71–77%), excepto U. expansa, para la cual el principal esterol fue el fucoesterol+isofucosterol (79%). El contenido de pigmentos fue diferente entre las algas, aunque coincidio con reportes previos. Los componentes bioquimicos usados como biomarcadores se analizaron por componentes principales para discriminar entre las variables analizadas y agrupar las especies de algas en funcion de la variabilidad de su composicion bioquimica. Los resultados mostraron una composicion similar en cada grupo de algas, pero particularmente diferente en U. expansa y P. durvillaei. Los compuestos bioquimicos que contribuyeron a la variabilidad total fueron β-sitosterol, 20:4n-6, 20:5n-3, clorofila a y b, β-caroteno y, en menor grado, fucosterol+isofucosterol y 22:6n-3. Los resultados indican que las especies de algas analizadas podrian ser utilizadas como alimento para animales, pero tambien para consumo humano. EnglishBiochemical composition was assessed in green ( Ulva expansa, Caulerpa sertularioides, Rhizoclonium riparium, Codium isabelae), red ( Spyridia filamentosa, Gracilaria vermiculophylla), and brown (Padina durvillaei) seaweeds collected from different tropical lagoons on the Pacific coast of Sinaloa, Mexico. Protein content was higher in C. sertularioides, S. filamentosa, and G. vermiculophylla (10–12%), followed by R. riparium, P. durvillaei, and U. expansa (8%, 6%, and 4%, respectively). Lipid content was in the range of 0.3–1.5%, with the highest value found in R. riparium. The highest content of nitrogen-free extract (i.e., carbohydrates) (69%) and the lowest ash value (25%) were assessed in P. durvillaei. Polyunsaturated fatty acid content was in the range of 5–45%, with higher values in R. riparium (45%), C. sertularioides (39%), and P. durvillaei (23%). Red seaweeds showed the highest value of cholesterol+dehydrocholesterol (>90%), while green seaweeds showed the highest contents of β-sitosterol (71–77%), except for U. expansa, for which fucosterol+isofucosterol (79%) was highest. Pigment composition was different among seaweeds but coincided with previous reports. The biochemical components used as biomarkers were assessed by principal component analysis to discriminate among assessed variables and to cluster seaweed species according to the common variability of their biochemical composition. Results showed that composition was similar within seaweed divisions but particularly different in U. expansa and P. durvillaei. Biochemical compounds that contributed to total variability were β-sitosterol, 20:4n-6, 20:5n-3, chlorophyll a and b, and β-carotene, and to a lesser extent fucosterol+isofocusterol and 22:6n-3. Results showed that the analyzed seaweed species may be useful for animal nutrition and appropriate for human consumption.

This chapter is centered on fundamental and applied aspects of polysaccharides and their capability to form nanoparticles to be used as oral drug delivery systems. Polysaccharides are natural biopolymers diverse in size, charge as well as complex and diverse in chemical structure. They participate in the life process and are used in health, food and cosmetics industries due to its biocompatibility and biodegradability. Polysaccharides have been studied for therapeutic purposes as an alternative to developing less invasive and more personalized treatments that allow the use of lower drugs doses and the reduction of side effects caused by medications when levels are outside of the therapeutic range. Different methods reported for polysaccharide nanoparticles fabrication as well as how they are selected depending on factors such as particle size, stability, active agent and toxicity, among others, are discussed. Examples of nanoparticles based on polysaccharides as carriers and oral delivery system are described, emphasizing their capability to improve drug stability against enzymatic degradation in the gastrointestinal environment due to the protective polymer network. Finally, it is evident that polysaccharides can represent an attractive alternative for the development of specialized formulations in nanomedicine since these macromolecules offer a variety of beneficial and exclusive physicochemical properties. Furthermore, polysaccharides represent an abundant group of biopolymers available from renewable sources. For all these reasons, polysaccharides appear to be remarkable based on materials for oral drug delivery nanoparticle systems.