Baixa digestibilidade proteica e presença de antinutricionais em produtos tipo mix de cereais / Low protein digestibility and anti-nutritional factors in cereal mix like products

Products composed of cereal mixes and other ingredients such as guarana, gelatin and cocoa powders; yeast; and soybean, flaxseed and sesame extracts have presented increased sales while receiving ever-growing criticism. Amongst the ingredients that could compose this cereal mix, most are of vegetable origin, wholegrain and not thermally processed. Therefore, they may present anti-nutritional factors, which are recognized to harm the bioavailability of nutrients, such as proteins. In this study, we aimed to evaluate the protein quality of these products, sold in the municipality of Uberaba, Brazil. The protein digestibility, tannins and trypsin inhibitors of the 14 samples were assessed. All samples showed trypsin inhibition activity and tannins. These results suggest that those products present low potential for nutrient utilization, especially with regards to proteins.

Productos compuestos por mezclas de cereales y otros ingredientes, como guaraná en polvo, gelatina en polvo, cacao en polvo, levadura de cerveza, extracto de soja, linaza y ajonjolí, presentan creciente comercialización, al mismo tiempo que aumentan los cuestionamientos al respecto. Estos productos están compuestos de variados ingredientes, la mayoría de origen vegetal, integral y sin procesamiento térmico previo, y podrían presentar antinutricionales, reconocidamente capaces de perjudicar la biodisponibilidad de nutrientes, tales como las proteínas. Este estudio evaluó la calidad proteica de productos listos para el consumo, compuestos por mezclas de cereales y otros componentes, comercializados en la ciudad de Uberaba-MG, determinando sus niveles antinutricionales y su digestibilidad proteica in vitro. Todas las muestras analizadas presentaron inhibición en la actividad de tripsina y de taninos. Las muestras presentaron muy claramente bajos valores de digestibilidad proteica in vitro. Los resultados sugieren que estos productos presentan bajo potencial de utilización de sus nutrientes, muy especialmente con respecto a sus proteínas.

Misturas de cereais e outros ingredientes, como guaraná em pó, gelatina em pó, cacau em pó, levedo de cerveja, extrato de soja, linhaça e gergelim, vêm apresentando crescente comercialização, concomitantemente com crescentes questionamentos a seu respeito. Dentre os ingredientes variados que podem compor estes produtos, a maioria é de origem vegetal, integral e sem processamento térmico prévio, e poderiam apresentar antinutricionais, reconhecidamente capazes de prejudicar a biodisponibilidade de nutrientes, como proteínas. Este trabalho buscou avaliar a qualidade proteica de produtos prontos para o consumo, compostos por misturas de cereais e outros componentes, comercializados no município de Uberaba-MG, determinando seus teores de antinutricionais e sua digestibilidade proteica in vitro. Todas as amostras analisadas apresentaram atividade de inibição de tripsina e teores de taninos, e baixa digestibilidade in vitro.

Concomitant production of protease and lipase by Bacillus licheniformis VSG1: production, purification and characterization

This study was aimed at producing protease and lipase simultaneously on a common medium by Bacillus licheniformis VSG1, which was isolated from a tannery effluent. The effect of media composition with respect to protein source, lipid source and emulsifier on the production of protease and lipase was analysed. Both those enzymes were produced under optimized conditions like pH, temperature and incubation time. The enzyme mixture comprising of both protease and lipase was purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography to obtain 20-fold pure enzymes. The purified enzyme mixture was characterized to determine the optimum pH and temperature of protease and lipase, the response of the enzymes to inhibitors, additives and solvents. The molecular weight of both the enzymes was determined as 40 kDa on SDS-PAGE. The concomitant production of protease and lipase and the purification of both the enzymes in a single mixture have industrial significance, as many industrial processes use both protease and lipase together.

Giardia duodenalis: inter-strain variability of proteins, antigens, proteases, isoenzymes and nucleic acids

Os isolados de Giardia duodenalis de individuos assintomaticos, de pacientes e de animais apresentam diferencas e semelhancas em sua composicao proteica, expressao de antigenos, proteases e isoenzimas, assim como na constituicao dos acidos nucleicos. A presente revisao analisa estas diferencas com enfase na interacao parasita e hospedeiro, e nos possiveis mecanismos de virulencia do protozoario

Presencia de lectinas, taninos e inhibidores de proteasas en algas marinas de las costas Venezolanas / Presence of lectins, tannins and protease inhibitors in Venezuelan marine algae

Se estudió la presencia de lectinas, taninos e inhibidores de proteases, en 27 especies de algas colectadas en barreras coralinas de cuatro regiones de Venezuela. Sólo seis de las especies estudiadas, presentaron actividad hemaglutinante atribuible a lectinas, obteniéndose los mayores títulos de hemaglutinación com eritrocitos tratados con pronasa. En cuatro de las especies, las lectinas fueron inhibidas por más de un azúcar sencillo y por la mucina de glándula submaxilar de bovino: Caulerpa sertularioides, Enteromorpha intestinalis, Codium repens y Codium isthmocladum (Chlorophyta). La lectina de Grateloupia filicina fue inhibida solamente por NAcGal. Ninguno de los compuestos probados inhibió la hemaglutinación causada por Halimeda opuntia. El tratamiento de los extractos con polivinilpolipirrolidona eliminó la actividad hemaglutinante de las algas pardas y rojas, menos en dos especies de rodofitas: Grateloupia filicina e Hypnea cervicornis, lo que hace presumir la presencia de lectinas en ambas. Los taninos presentes en las Phaeophyta y Rhodophyta estudiadas son aparentemente del tipo florotaninos con un mayor contenido en las primeras. Sólo se encontró actividad inhibidora de tripsina en: Padina gymnospora (Phaeophyta) y Acantophora spicifera (Rhodophyta). En ningún caso se encontró actividad inhibidora contra subtilisina.

A study of antitrypsin and macroglobulin levels in serum and saliva of patients with gingivitis.

Periodontal diseases are associated with chronic inflammation. The destruction of connective tissue matrix is responsible for the pathogenesis of chronic inflammatory states. The degradation of matrix is initiated extra and pericellularly by proteinases produced locally at the inflammatory site. The regulation of these proteinases are by inhibitors present in serum and extravascular tissues, and it is the proteinase/proteinase inhibitor balance that determines the progression of chronic inflammatory state. Few contradicting studies are available on changes in the levels of proteinase inhibitors in serum in periodontal disease. The occurrence of these inhibitors in saliva has not been studied in detail. The present study was aimed at measuring the Proteinase inhibitors in serum and saliva of patients with periodontal disease.

Bacterial chemistry-III: preliminary studies on Trypanosomal activities of Chromobacterium violaceum products

It has been found that the pigment-I from Chromobacterium violaceum, 3 [1,2 dihydro 5 (5 hydroxy 1H indol 3 yl) 2 oxo 3H pyrrol-3 ylidiene] 1,3 dihydro 2H indol 2 one, has trypanocide activity. The formylated derivatives, pigment-III, immobilized 100% of the Trypanosoma cruzi at a level of 46 micronM after 48h of interaction with a total growth inhibition in the same period. Pigment I exhibited low toxicity and a DNA synthesis inhibition similar to that of Nifurtimox, a known trypanocide compound

Structural similarity in Bowman-Birk type protease inhibitors based on hydrophobicity

The degree of similarity in the three-dimensional structures of thirteen legume Bowman-Birk type protease inhibitors has been examined on the basis of the patterns of hydrophobicity found in their amino acid sequences, following the procedure described by Sweet & Eisenberg (1983). In the group of such double-headed protease inhibitors two sub-groups are distinguished presenting high structural similarity among their respective members and low similarity between them. Phylogenetic trees have been constructed from hydrophobicity difference and minimum mutational distance matrices, respectively