Ultrasonic pulses are considered green technology for the improvement of the functional properties of proteins. In this study, four high-intensity ultrasound pulse treatments (ultrasound-pulsed gelatin (UPG)-42, UPG-52, UPG-71, UPG-84, and non-pulsed control gelatin (CG)) were applied to tilapia (Oreochromis niloticus) skin gelatin in order to study their effect on its physicochemical and antioxidant properties; a non-treated gelatin was used as a control. UPGs showed a significant increase in soluble protein and surface hydrophobicity compared to the control gelatin, and no significant difference was found in the electrophoretic profiles. The effects on the secondary structure were studied by circular dichroism and infrared spectra, and these showed that the random coil conformation was the main component in all treatments and the ultrasonic treatments only affected the α-helix and β-sheet proportion. Finally, the ABTS ((2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (ferric reducing ability) assays demonstrated that ultrasound treatments could improve the antioxidant activity of gelatins as free radical scavengers and electron donors. These results suggest that high-intensity ultrasound pulse technology is useful to improve fish gelatin antioxidant properties, which could be associated with secondary structure disruption.

El propósito del estudio fue identificar cambios significativos en las variables cinemáticas del tiro de baloncesto con relación a la distancia desde el aro en jugadoras infantiles de la rama femenil. Participaron niñas entre 10 y 11 años de edad pertenecientes a la Selección Estatal Sonorense de Baloncesto, con experiencia de práctica deportiva de cuando menos dos años. Los sujetos realizaron tiros a la canasta a distancias de 2, 3, 4, 5 y 6 metros del aro y se midieron las variables cinemáticas respuesta de ángulos relativos del codo y rodilla, y de ángulos absolutos de hombro y tronco. Se encontraron diferencias significativas (p≤0.05) en las medias de las variables cinemáticas a causa de la distancia de tiro, excepto en distancias adyacentes en las variables de ángulo de codo (4-5m, 3-4m), inclinación del tronco (4-5m), ángulo de rodilla (4-5-6m, 3-4m) y ángulo absoluto del hombro (3-4m). Los resultados sugieren que realizar un alto volumen de repeticiones de tiro a la canasta en distancias mayores a cuatro metros distorsiona significativamente la técnica del tiro, lo que provoca la generación de un hábito motor incorrecto. Palabras clave: baloncesto, infantil femenil, tiro a la canasta, distancia, cinemática.

Trypsin from the viscera of sierra (Scomberomorus sierra) was purified by affinity chromatography on Sepharose-4B coupled to soybean trypsin inhibitor and characterized with respect to its purity, sensitivity to temperature, pH and inhibition. Trypsin was purified from sierra viscera with 11.9-fold and 29.7% yield. The enzyme had a molecular weight of 25.4 kDa estimated by SDS-PAGE and two possible trypsin isoforms were observed in activity gels. Trypsin activity was strongly inhibited by soybean trypsin inhibitor and porcine trypsin inhibitor, showing a partial inhibition by a serine protease inhibitor. The optimal activity of the enzyme was observed at pH 9 and 60C with n-a-benzoyl-dl-arginine-p-nitroanilide as a substrate. The enzyme maintained more than 50% of its activity in temperatures up to 50C and within the pH range of 8-10 for a period of up to 2 h. PRACTICAL APPLICATIONSThe potential applications of purified trypsin from tropical sierra fish viscera are those that are already in use for trypsin, such as an aid for hydrolysis of food proteins, as an aid in reducing viscosity of stickwater from fish processing plants, and in obtaining bioactive fractions from protein hydrolisates. Specific uses of this particular trypsin from tropical sierra could be those that comply with the optimum conditions at 60C and pH 9-10 or stability described in the results. bs_bs_banner Journal of Food Biochemistry

Interest in developing novel wound dressings with antibacterial properties elaborated from natural sources continues to grow. In this study, a Tween-80 (T80)-stabilized carvacrol (CAR) emulsion was incorporated into pectin (PEC) membranes at 0 (control), 0.25, 0.50, and 1.00% (v/v). Membranes were obtained by the dry-casting method, characterized by scanning electron microscopy, infrared spectroscopy, and CAR retention (HPLC), and tested for antibacterial activity. The retention percentage of CAR in the membranes ranged from 9.1-13.9%. Infrared spectra analysis indicated changes in the hydrogen bonds of the membranes that suggest an interaction between the polymer matrix and the CAR:T80 emulsion. Microstructural analysis of the membranes showed the presence of hole-like features on the surface (≈ 4-6 µm diameter) that indicate entrapment of the micelles in the matrix (microcapsules). The PEC-CAR membranes exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus, two pathogens commonly associated with wounds and intra-hospital infections.

El propósito del estudio fue identificar cambios significativos en las variables cinemáticas del tiro de baloncesto con relación a la distancia desde el aro en jugadoras infantiles de la rama femenil. Participaron niñas entre 10 y 11 años de edad pertenecientes a la Selección Estatal Sonorense de Baloncesto, con experiencia de práctica deportiva de cuando menos dos años. Los sujetos realizaron tiros a la canasta a distancias de 2, 3, 4, 5 y 6 metros del aro y se midieron las variables cinemáticas respuesta de ángulos relativos del codo y rodilla, y de ángulos absolutos de hombro y tronco. Se encontraron diferencias significativas (p≤0.05) en las medias de las variables cinemáticas a causa de la distancia de tiro, excepto en distancias adyacentes en las variables de ángulo de codo (4-5m, 3-4m), inclinación del tronco (4-5m), ángulo de rodilla (4-5-6m, 3-4m) y ángulo absoluto del hombro (3-4m). Los resultados sugieren que realizar un alto volumen de repeticiones de tiro a la canasta en distancias mayores a cuatro metros distorsiona significativamente la técnica del tiro, lo que provoca la generación de un hábito motor incorrecto. Palabras clave: baloncesto, infantil femenil, tiro a la canasta, distancia, cinemática.