Propiedades nutritivas y tecno funcionales de barras de pseudocereales adicionadas con soya, mango y granada / Nutritional and techno functional properties of pseudocereal bars added with soy, mango and pomegranate

Las barras de cereal (BC), se comercializan como un snack saludable, no obstante, su calidad nutricional es baja. Una alternativa para mejorar esto, es la incorporación de ingredientes como pseudocereales, germinados y subproductos de fruta. Objetivo. Evaluar el contenido nutricional y propiedades tecnofuncionales de una barra de cereal formulada a partir de pseudocereales, germinados de soya y subproductos del procesamiento de frutas. Materiales y Métodos. Se desarrollaron 6 formulaciones (F0-F5). Se determinó el contenido de proteína y fibra cruda, se seleccionó la formulación que presentó el mayor contenido de estos componentes. A la BC seleccionada se le determinó la digestibilidad in-vitro de la proteína, las propiedades tecnofuncionales potencial prebiótico y actividad inhibitoria de ECA-I. Resultados. La formulación seleccionada fue F1 (13,6 g/100 g p.s. proteína y 13,1 g/100 g p.s. fibra cruda). La digestibilidad de la proteína fue del 69 %, el cual es cercano a valores reportados para algunos componentes de la BC. La capacidad de hinchamiento y retención de agua fue 2,55 ml/g; 12,74 %, respectivamente. El crecimiento de L. brevis en medio MRS modificado con BC no presentó diferencias estadísticas con el medio control, indicando el potencial prebiótico presente en la BC. La barra de cereal tuvo un 39% de actividad inhibitoria de ECA-I, demostrando la acción de los compuestos bioactivos posiblemente liberados durante la digestión de la BC. Conclusión. La formulación desarrollada presenta propiedades funcionales importantes y podría generar beneficios para la salud(AU)

Introduction. Cereal bars (CB) are marketed as a healthy snack; however, their nutritional quality is low. An alternative to improve this is the incorporation of ingredients such as soybean sprouts, which have a higher protein content than some seeds; as well as fruit by-products that contain important bioactive compounds. Objective. To evaluate the nutritional content and techno-functional properties of a cereal bar formulated from pseudocereals, soybean sprouts, and fruit processing by-products. Materials and Methods. 6 formulations (F0-F5) were developed. The content of protein and crude fiber was determined, the formulation that presented the highest content of these components was selected. The in-vitro digestibility of the protein, the technofunctional properties, potential prebiotic and inhibitory activity of ACE-I were determined for the selected BC. Results. The selected formulation was F1 (13.6g/100g p.s. protein and 13.1g/100 g p.s. crude fiber). Protein digestibility was 69%, which is close to reported values for some CB components. The swelling and water retention capacity was 2.55 ml/g; 12.74%, respectively. The growth of L. brevis in modified MRS medium with CB did not present statistical differences with the control medium, indicating the prebiotic potential present in CB. The cereal bar had 39% ACE-I inhibitory activity, demonstrating the action of bioactive compounds possibly released during CB digestion. Conclusion. The developed formulation has important functional properties and could generate health benefits(AU)

Halophilic hydrolases as a new tool for the biotechnological industries.

Halophilic micro-organisms are able to survive in high salt concentrations because they have developed diverse biochemical, structural and physiological modifications, allowing the catalytic synthesis of proteins with interesting physicochemical and structural properties. The main characteristic of halophilic enzymes that allows them to be considered as a novel alternative for use in the biotechnological industries is their polyextremophilicity, i.e. they have the capacity to be thermostable, tolerate a wide range of pH, withstand denaturation and tolerate high salt concentrations. However, there have been relatively few studies on halophilic enzymes, with some being based on their isolation and others on their characterisation. These enzymes are scarcely researched because attention has been focused on other extremophile micro-organisms. Only a few industrial applications of halophilic enzymes, principally in the fermented food, textile, pharmaceutical and leather industries, have been reported. However, it is important to investigate applications of these enzymes in more biotechnological processes at both the chemical and the molecular level. This review discusses the modifications of these enzymes, their industrial applications and research perspectives in different biotechnological areas.

A process to produce penicillin G acylase by surface-adhesion fermentation using Mucor griseocyanus to obtain 6-aminopenicillanic acid by penicillin G hydrolysis.

The production of extracellular and mycelia-associated penicillin G acylase (maPGA) with Mucor griseocyanus H/55.1.1 by surface-adhesion fermentation using Opuntia imbricata, a cactus, as a natural immobilization support was studied. Enzyme activity to form 6-aminopencillanic acid (6-APA) from penicillin G was assayed spectrophotometrically. The penicillin G hydrolysis to 6-APA was evaluated at six different times using PGA samples recovered from the skim milk medium at five different incubation times. Additionally, the effect of varying the penicillin G substrate concentration level on the PGA enzyme activity was also studied. The maximum reaction rate, V (max), and the Michaelis constant, K (M), were determined using the Michaelis-Menten model. The maximum levels for maPGA and extracellular activity were found to be 2,126.50 international unit per liter (IU/l; equal to 997.83 IU/g of support) at 48 h and 755.33 IU/l at 60 h, respectively. Kinetics of biomass production for total biomass showed a maximum growth at 60 h of 3.36 and 2.55 g/l (equal to 0.012 g of biomass per gram of support) for the immobilized M. griseocyanus biomass. The maPGA was employed for the hydrolysis of penicillin G to obtain 6-APA in a batch reactor. The highest quantity of 6-APA obtained was 226.16 mg/l after 40-min reaction. The effect of substrate concentration on maPGA activity was evaluated at different concentrations of penicillin G (0-10 mM). K(M) and V(max) were determined to be 3.0 x 10(-3) M and 4.4 x 10(-3) mM/min, respectively.