Abstract Biomaterials developed with biopolymers contribute to the healing process of healthy or diabetic patients. The objective of the present study was to evaluate the effect of honey incorporation (0.3, 0.6, and 1.2 g/100 mL) in chitosan/collagen/glycerol composite films. The Ch/Coll/1.2H films revealed the greatest percentage of elongation (27.10%) and Young´s modulus (65.58 MPa). The barrier properties (WVTR and WVP) exhibited a significant increase when the honey was incorporated into the films. The absorption capacity, solubility, and enzymatic biodegradability were lower in films containing honey. The chemical interactions between the functional groups of the films were verified by FTIR. The morphology studied by SEM confirmed the mixture’s homogeneity. Finally, all formulations exhibited antibacterial properties against Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, and Salmonella Typhimurium. The aforementioned properties of formulated dressings are suitable for their potential application in chronic wounds.

ABSTRACT Intensive horticultural crop production usually involves challenges from excessive application of fertilizer, mainly nitrogen (N). The effect of N fertilizer on the fruit quality and antioxidant status of two cherry tomato cultivars (Caballero and Victoria) under greenhouse conditions was performed. Nitrogen treatments were applied ranging from conditions comprising deficiency to toxicity (0, 15, 30, 45 and 60 mmol∙L-1). Yield, weight, diameter, fruit quality, phenols, flavonoids, lycopene, ascorbic acid and antioxidant capacity were measured at physiological maturity of the fresh tomato fruits. N treatment with 30 mmol∙L-1 produced the highest yield, fruit weight, firmness and diameter in both cultivars. However, increasing N from 30 to 60 mmol∙L-1 increased the concentration of phenolics, flavonoids, and antioxidant capacity by 50, 125 and 33% in ‘Caballero’ tomatoes and by 60, 95 and 24% in ‘Victoria’ tomatoes, respectively. Lycopene content increased with increasing N doses (45 and 60 mmol∙L-1) for ‘Caballero’ tomatoes, while vitamin C decreased as N concentration increased, suggesting that ascorbic acid acts by protecting against oxidative stress in tomato. The present work shows how N fertilization considerably influences yield and quality of tomatoes, as well as nutritional and healthy values.

Abstract Electrospun nanofibers from gelatin (G), chitosan (CS), and chitosan-polyvinyl alcohol (CS-PVA) were developed by electrospinning process. Mechanical properties were determined by the tensile test, the elastic modulus values of the nanofibers were G (15.418-34.34 MPa) and CS-PVA (17.44-126.427 MPa). The morphological characterization by SEM revealed that the systems with 15% G and 6% CS-PVA showed morphological homogeneity. Structural characterization by FTIR indicated an interaction among some functional groups of the component. Thermal analysis by DSC and TGA showed degradation temperatures for G (330 °C), CS (210 °C to 370 °C), and PVA (310 °C to 420 °C). The contact angles values denoted the hydrophilic nature of the material. Finally, the antimicrobial assay proved that both 15% G and 7% PVA on the CS-PVA system presented the best antimicrobial effect. The results indicate that the electrospun nanofibers fabricated with G or CS-PVA can be used as wound healing dressings.

The presence of dietary fiber (DF) in the food matrix of some tropical fruits plays an important role in the release and absorption of its bioactive compounds, such as phenolic compounds (PCs). The aim of this study was to evaluate the effect of the DF fractions in mango cv. ‘Ataulfo’, papaya cv. ‘Maradol’ and pineapple cv. ‘Esmeralda’, on the bioaccessibility of their PCs and antioxidant capacity (AOXC) under an in vitro digestion model. The highest PCs content and AOXC was found in mango (274.30 mg GAE/100 g FW), followed by papaya (212 mg GAE//100 g FW), and pineapple (107.63 mg GAE/100 g FW), respectively. About 50% of the total PCs in all fruits was released at gastric phase, increasing closer to 60% at intestinal phase in mango and pineapple. However, the highest content of PCs associated to DF was found in mango (2.48 mg GAE/100 g FW) compared with papaya DF fractions (0.96 GAE/100 g FW) and pineapple (0.52 GAE/100 g FW). The presence of DF in mango, papaya and pineapple did not represent a major limitation on the bioaccessibility of its PCs according to the in vitro digestion model used in this study.

Recently the food, pharmacy and cosmetic industries have focused on the search for natural compounds with antimicrobial and antioxidant properties, commonly these compounds are obtained from plants. Nowadays, macroscopic fungus are being considered for the extraction these compounds. For this reason, the objective of the present work was to evaluate the antibacterial and antioxidant capacity of fractionated methanolic extracts (polar and non-polar) from Phellinus merrillii. The non-fractionated methanolic extract showed the highest content of phenolics (913.91 mg gallic acid equivalents/g, mgGAE/g), flavonoids (563.83 mg quercetin equivalents/g, mgQE/g), the lowest efficient concentration to inactivate the 50% of the free radical DPPH (0.1767 g/L), and the highest inhibition percent against Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica Choleraesuis and Listeria monocytogenes. Followed by the non-polar fraction with values 254.50 mgGAE/g, 179.44 mgQE/g and 0.7238 g/L, and the polar fraction 254.50 mgGAE/g, 163.98 mgQE/g and 1.1767 g/L. Moreover, the antibacterial activity correlated positively with the total phenolic, flavonoid content and antioxidant activity for all the extracts. Therefore, P. merrillii could be a source of antibacterial and antioxidant extracts.

En los últimos años las industrias de alimentos, farmacéutica y cosmética se han enfocado en la búsqueda de compuestos naturales con propiedades antimicrobianas y antioxidantes, los cuales se obtienen principalmente de plantas. Sin embargo, recientemente los hongos han sido considerados foco de estudio para la extracción de estos compuestos. Es por ello que el objetivo del presente trabajo fue evaluar la capacidad antibacteriana y antioxidante de extractos metanólicos fraccionados (polar y no polar) del hongo Phellinus merrillii. El extracto metanólico sin fraccionar presentó el mayor contenido de fenoles (913.91 mg de equivalentes de ácido gálico/g, mgEAG/g), flavonoides totales (563.83 mg de equivalentes de quercetina/g, mgEQ/g), la concentración eficiente más baja para inhibir el 50% del radical libre DPPH (0.1767 g/L) y el mayor porcentaje de inhibición contra Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica Choleraesuis y Listeria monocytogenes. Seguido de la fracción no polar con valores de 254.50 mgEAG/g, 179.44 mgEQ/g y 0.7238 g/L, y la fracción polar 254.50 mgEAG/g, 163.98 mgEQ/g y 1.1767 g/L. Adicionalmente, la inhibición bacteriana correlacionó positivamente con el contenido de fenoles, flavonoides y actividad antioxidante para todos los extractos. Por ello, el hongo P. merrillii podría ser una fuente de extractos con propiedad antibacteriana y antioxidante.

Complexation of chlorogenic acid (CA) by β-cyclodextrin (β-CD) at mildly acidic pH, was studied by fluorescence spectroscopy, isothermal titration calorimetry (ITC), cyclic voltammetry (CV) and NMR spectroscopy. Thermodynamic parameters (ΔH°, ΔS° and K) determined by both fluorescence and ITC, showed that the complexation of CA by β-CD is an enthalpy-driven process. Results show that CA molecule can be complexed through both polyphenolic and quinic acid moiety, leading to the formation of two supramolecular isomers with 1:1 stoichiometry.

La complejación del ácido clorogénico (AC) por β-ciclodextrina (β-CD) a pH ligeramente ácido se estudió por espectroscopia de fluorescencia, calorimetría isotérmica de titulación (CIT), voltamperometría cíclica (VC) y RMN. Los parámetros termodinámicos del sistema ((ΔH°, ΔS° and K) determinados por fluorescencia e CIT sugieren que la complejación está regulada por procesos entálpicos. De los resultados obtenidos, se puede deducir que las moléculas del AC pueden ser complejadas tanto por la región fenólica como por la región quínica, dando lugar a la formación de dos isómeros supramoleculares con estequiometría 1:1.