Crescimento micelial associado ao efeito da concentração de spawn na produção de cogumelo e peptidases para a fabricação de alimentos.

Abstract

The consumption of natural foods rich in bioactive compounds beneficial to human health has been growing every year. Edible mushrooms are considered natural sources of peptidases with promising biochemical properties for food manufacturing. The objective of this work was to evaluate mycelial growth and investigate the production and characterization of peptidases from Pleurotus albidus DPUA 1692 for biomass application in the formulation of a food product with nutritional characteristics for health promotion. The species provided by the DPUA culture collection, from the Federal University of Amazonas, was reactivated in BDA+ Yeast Extract agar 0.5% (w/v). To select the culture medium in order to obtain the inoculum of P. albidus, synthetic potato agar, malt agar, Sabourad agar, Corn agar and purple yam agar were used, supplemented with 0.5% yeast extract (w/v). After selection of the inoculum, vertical mycelial growth, production of peptidases were carried out in solid state fermentation using cupuaçu exocarp, açaí seed, pineapple exocarp and sawdust, supplemented with rice bran or wheat bran, sterilized at 121 °C for two consecutive days, the bioprocess was carried out at 25 °C, for 15 days, in the absence of light. Peptidases were extracted in sterilized distilled water, under stirring at 180 rpm, at 30 °C. The proteolytic activity was determined with 1% azocasein solution (w/v). The enzyme was biochemically characterized regarding the effect of pH and temperature on activity and stability, in addition to evaluating the effect of metal ions and inhibitors on the catalytic action of the biocatalyst. The production of basidiomas was carried out in the substrate that showed satisfactory vertical mycelial growth and vigorous mycelium. Biological efficiency, productivity, rate of production and loss of organic matter, microbiological quality and the nutritional value of the residue, basidiomas and of the food supplement product were determined. The proximate composition, microbiological quality and technological characteristics of the flour were evaluated in this feed. Sabouraud +YE favored radial mycelial growth and was selected to obtain the inoculum of P. albidus. In cupuaçu exocarp supplemented with rice bran (CC+FA) the mushroom developed strongly dense mycelium and was used for basidioma production. Significant proteolytic activity (208.1 U/mL) was also verified on this same substrate, the peptidases showed optimal activity at pH 6.0 at 40 °C, these results indicate that P. albidus excretes peptidases with potential for use in the production of bakery products.