Extração de fibras insolúveis do resíduo farelo de trigo.

The generation of waste and by-products is inherent to any productive sector. The agroindustrial sectors produce large quantities of waste, which can present high final disposal problems and potential pollutants, and often represent losses of biomass and high-value nutrients. Among the agroindustrial chains, the wheat processing chain is praised for treating the cereal with the largest volume of production in the world, which generates significant volumes (23%) of waste (wheat bran), representing a major problem for the milling industry . Wheat bran is a renewable and poorly exploited food resource, although it is one of the richest sources of fiber, mainly insoluble fibers. Fiber fibers present several benefits to human health, being considered as functional component, acting in the prevention of several diseases. The food industry, attentive to the scenario, are developing several products enriched with fibers, aiming to meet the growing demand of individuals interested in a healthier diet. However, single fibers are expensive and their supply is currently restricted by international companies. In view of this context, the objective of the work is to develop or improve a methodology for the extraction of insoluble fiber from wheat bran, with the wheat mills being applied as well as obtaining a new product with higher added value, the insoluble fibers available for commercialization and In the food industry. This work was subdivided into three stages: 1) systematic bibliographical review, 2) physicochemical characterization of different wheat bran, and 3) experimentation of different methodologies for the extraction of insoluble fibers. In the experimentation of different extraction methods, the first preliminary experiment (EP-I) varied the content of the aqueous extraction solution between acids and bases. When the ideal aqueous solution was determined, preliminary experiment II (EP-II) was used in a completely randomized design, in a 3x2 factorial scheme with 3 different temperatures and at 20 and 30 minutes. The preliminary experiment III (EP-III), which worked on the purification step of the extracted solution, was carried out with the solution of ultrafiltration and activated carbon. With three preliminary experiments carried out, the extractive experiment was based on the main stage of the process, which is exactly the extraction phase, where it was varied between enzymatic, physical and mixed treatments.As a result ten patents related to the fiber extraction process were found, of which nine deal with the enzymatic extraction and only one of the physical extraction. The wheat bran samples analyzed had insoluble fiber contents between 39.9 - 44.1%, and the M3 sample had the highest content (44.1%). Among the extraction processes, the best results were E1 - physical treatment, with 12.3% of insoluble fibers in samples M1 and M2. The physical treatment extraction process showed an average yield of approximately 29%. The product obtained was an aqueous solution of fibers, which may or may not be subjected to the drying process. Therefore, the methodology of fiber extraction proposed by this work is summarized in: removal of impurities with ethyl alcohol; extraction in aqueous solution with pure water; autoclaving with minimum temperature and time of 174 °C and 20 minutes, respectively; centrifugation, purification with ultrafiltration membrane or reverse osmosis; bleaching and drying.