Elaboração de barras de cereais utilizando resíduos agroindustriais de goiaba e caju enriquecidos proteicamente por via microbiana.

Abstract

With traditional sources of protein becoming more expensive every day, there is a need to develop new food products with high nutritional value that are still low cost and can be consumed by the population of all economic classes. The cereal bars already represent an alternative food complement based on carbohydrates and fibers, so, this research aims to elaborate cereal bars containing in their composition agroindustrial residues, which undergo the process of microbial protein enrichment, will increase the protein and nutritional content of this respective product, besides making them cheaper. The microorganism used was the yeast Saccharomyces cerevisiae, and the residues chosen for this purpose were the cashew bagasse and the guava husks. Initially the waste was prepared, which were dried in an oven with air circulation at 55 ± 2 ° C until constant weight. The physico-chemical characterization of the cashew and guava residues showed that they could be submitted to the fermentative process of protein enrichment and later as ingredients in the elaboration of the cereal bars, presenting sufficient levels of reducing sugars, pectin and fibers, besides a pH suitable for culture medium. For protein enrichment, the yeast was used at a concentration of 3% for the cashew residue and 5% for the guava residue, at a temperature of 30 ° C for 9h of culture. Both the cashew and guava residue had their protein content elevated fourfold. After obtaining the protein enriched residues, four formulations of cereal bars were elaborated, where the oats were replaced partially by the agroindustrial residues, (F0) reference formulation without addition of none of the residues, (F1) constituted only by the cashew residue, F2) constituted only by guava residue and (F3) constituted by the two residues, guava and cashew. The elaborated cereal bars were physicochemically characterized as water, ash, lipids, carbohydrates, protein and dietary fiber, presenting satisfactory results, mainly regarding the protein content, around 12% for the formulation F1, value higher than that found in cereal bars marketed on the market. Subsequently, they were submitted to microbiological analysis to verify the absence/presence of total coliforms, fecal coliforms and salmonella sp., the results obtained were lower than the maximum stipulated by RDC n° 12, thus meeting the requirements of current legislation. Finally, the formulations were evaluated sensorially in a gymnasium of the city by a group of 40 judges who evaluated the attributes: color, aroma, flavor, texture and global acceptance, using a hedonic scale of 9 points, besides the intention to buy, using a hedonic scale of 5 points. The results obtained were satisfactory for all cereal bars analyzed by the judges who stated that they liked moderately (7) and that they would possibly buy (4) if they were marketed.