Incremento del valor nutrimental, actividad antioxidante y potencial inhibitorio de α-glucosida en brownies a base de leguminosas cocidas / Increase in nutritional value, antioxidant activity and inhibitory potential of α-glucoside in brownies from cooked legumes

El objetivo de la presente investigación fue evaluar el valor nutrimental, actividad antioxidante e inhibición de la enzima α-glucosidasa de brownies libres de gluten enriquecidos principalmente con leguminosas. Los brownies fueron elaborados principalmente con leguminosas cocidas de frijol pinto (Phaseolus vulgaris L.), alubia chica (Phaseolus vulgaris L.), garbanzo (Cicer arietinum L.) o lenteja (Lens culinaris L.) (300 g de producto). Cada producto fue dividido en porciones de 100 g cada uno. Posteriormente, se determinó su composición nutrimental, y de los extractos etanólicos libres y ligados obtenidos, se evaluó el contenido de fenólicos totales, flavonoides, actividad antioxidante y el potencial inhibitorio de la enzima α-glucosidasa. Los brownies a base de leguminosas cocidas fueron significativamente mejores que los comerciales, y presentaron un contenido de proteínas entre 6.2 y 6.9%, 1.6-4.2% de lípidos, 1.2-5.8% de fibra dietaria soluble y 11.7-21.5% de fibra dietaria insoluble. Los productos presentaron en mayor proporción a los ácidos grasos linolénico y linoleico, además fueron ricos en minerales. El contenido de fenólicos totales, y flavonoides varió dependiendo de la leguminosa con la cual se desarrolló el producto, así como de la fracción que se evaluó. La actividad antioxidante total fue mayor en los brownies de alubia. La mayor inhibición de α-glucosidasa la presentaron los extractos de brownies elaborados a base de lenteja (fracción libre) y garbanzo (fracción ligada). Los brownies elaborados con lenteja fueron sensorialmente los más aceptados. La introducción de este tipo de productos promoverá un consumo nutritivo de alimentos por personas de diferentes edades y con efectos benéficos en la salud(AU)

The aim of the present study was to evaluate the nutritional value, antioxidant activity and inhibition of α-glucosidase enzyme of gluten-free brownies enriched mainly with legumes. The brownies were elaborated mainly with cooked legumes of pinto (Phaseolus vulgaris L.), haricot bean (Phaseolus vulgaris L.), chickpea (Cicer arietinum L.) or lentils (Lens culinaris L.) (300 g of product). Each product was divided into portions of 100 g and the chemical and nutritive composition were determined. From the free and bound ethanolic extracts obtained, the content of total phenolics, flavonoids, antioxidant activity and the potential inhibitor of the α-glucosidase enzyme were evaluated. Brownies based on cooked legumes were significantly better than commercial brownies, with a protein content between 6.2 and 6.8%, 1.6-4.2% lipids, 1.2-5.8% soluble dietary fiber and 11.7-21.5% insoluble dietary fiber. The products had a higher proportion of linolenic and linoleic fatty acids, and they were rich in minerals. The content of total phenolics and flavonoids varied depending on the legume as well as the fraction that was evaluated. Total antioxidant activity was higher in haricot bean-brownies. The highest inhibition of α-glucosidase was detected in extracts obtained from lentil (free fraction) and chickpea (bound fraction) brownies. Brownies based on lentil were the most accepted in the sensory test. The introduction of this type of products promotes a nutritious consumption of foods by people of different ages with beneficial effects on health(AU)

Increase of content and bioactivity of total phenolic compounds from spent coffee grounds through solid state fermentation by Bacillus clausii.

Spent coffee grounds are waste material generated during coffee beverage preparation. This by-product disposal causes a negative environmental impact, in addition to the loss of a rich source of nutrients and bioactive compounds. A rotating central composition design was used to determine the optimal conditions for the bioactivity of phenolic compounds obtained after the solid state fermentation of spent coffee grounds by Bacillus clausii. To achieve this, temperature and fermentation time were varied according to the experimental design and the total phenolic and flavonoid content, antioxidant activity and antimicrobial activity were determined. Surface response methodology showed that optimum bioprocessing conditions were a temperature of 37 °C and a fermentation time of 39 h. Under these conditions, total phenolic and flavonoid contents increased by 36 and 13%, respectively, in fermented extracts as compared to non-fermented. In addition, the antioxidant activity was increased by 15% and higher antimicrobial activity was observed against Gram positive and negative bacteria. These data demonstrated that bioprocessing optimization of spent coffee grounds using the surface response methodology was an important tool to improve phenolic extraction, which could be used as an antioxidant and antimicrobial agents incorporated into different types of food products.

Use of whey as a culture medium for Bacillus clausii for the production of protein hydrolysates with antimicrobial and antioxidant activity.

The use of whey as a natural culture medium to produce hydrolysates with antimicrobial from Bacillus clausii is the objective of this research. The fermentation process was carried out at 25 ℃ for five days, where proteolytic activity, soluble peptides quantification, and antimicrobial activity using the disc diffusion method were determined every day. The fermented whey reached values ​​of proteolytic activity between 90 and 260 U ml-1 and a production of soluble peptides between 100 and 2070 µg ml-1. The maximum values ​​were reached after three days of fermentation to all determinations. In addition, the inhibition zone of fermented whey against Salmonella Typhimurium, Escherichia coli, Shigella flexneri, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis strains were 13.7, 13.2, 14.4, 14.6, 9.8, 15.7 mm, respectively. The hydrolysates inhibited the 2, 2'-azinobis (3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals by 85 and 80%, respectively. The whey was used to allow the growth of B. clausii and to generate peptides with antioxidant and antimicrobial activity through the hydrolysis of proteins present in the natural culture medium. This process could be used for the development of new dairy products added with probiotics.