| Abstract [eng] |
The aim of this study was to develop the technologies for corn processing waste utilization into biologically valuable ingredients, and to evaluate their possible use for functional bread production. The rational use of natural by-products and wastes generated during the production of grain is very important and promising area. The alternative heat treatment methods for microbial stabilization of such corn material, and the innovative biotechnological instruments ‒ enzymatic hydrolysis and microbial fermentation ‒ for the natural valuable components production, could be succesfully applied for safe functional food production. The yields of albumin, globulin and prolamin fractions, water absorption capacity, water solubility index, foaming capacity and foam stability, and emulsifying properties of albumins and globulins obtained from natural, extruded and treated by infrared irradiation corn byproducts were evaluated. Lacto-fermentation using P. acidilactici and L. sakei strains increased by 35 % the solubility and improved functional properties of corn albumins and globulins, also increased the prolamins digestibility by 18 %, and influenced the degree of prolamin hydrolysis by protease (F = 2.262, P < 0.0001). Fermentation with P. acidilactici affected the changes of protein functional and technological properties at a higher degree than with L. sakei. The highest impact of lacto-fermentation was reported on the proteins isolated from IR treated corn byproducts. The use of optimized amylase and hemicelulases composition was shown to be an effective bio-tool to increase the yield of all corn protein fractions. Therefore, the results indicated that corn grain processing by-products are suitable substrate for the culture of the antimicrobial LAB strains. Metabolites produced after 48 h fermentation of corn by-products by P. acidilactici and three P. pentosaceus strains showed the antifungal activity inhibiting the growth of Fusarium graminearum and Fusarium culmorum. This indicates that corn processing waste or its extracts could be used in new funcrional food developments. The addition of 10 % of thermally treated corn by-products, fermented by P. pentosaceus, producing the bioactive metabolites in corn by-products medium, improved rye bread quality and acceptability, comparing to non-fermented raw material, therefore these corn products can be recommended for the production of bread to increase its nutritional value and safety. |
