Caracterização das fibras alimentares em borras de café expresso submetidas à tratamento com peróxido de hidrogênio alcalino

Abstract

The objective of this study was to obtain post rich dietary fiber power (PRF) from the coffee grounds expressed in raw form and modified in different concentrations with alkaline hydrogen peroxide. From these powders, there was the characterization by means of physical-chemical analysis (moisture, fixed mineral residue, ether extract and soluble and insoluble dietary fiber). The technological properties were evaluated by determining the water absorption capacity (WAC), oil absorption capacity (OBC) Swelling volume (SV) and water solubilty capacity (WSC). The colorimetric analyzes were performed using 10 observation angle and standard illuminant D65 (daylight). Total extractable phenolic tests by the Folin-Ciocalteu method and also of non-extractable proanthocyanidins-NEPA by the method butanolHCl treatment (butanolysis) and the proof test of antioxidant capacity by DPPH method. The results showed that treatment with alkaline hydrogen peroxide was effective to improve the technological properties of the fibers. The treatment provided significant changes in the color parameters, physicochemical properties, as well as in yield and particle size obtained. The treatment had a significant impact on the antioxidant activity measured by DPPH method. While the chemical treatment with hydrogen peroxide to provide a decreased content of phenolic compounds and which was correlated with a lower antioxidant activity assessed by the DPPH method, proanthocyanidins content not extractable obtained in high concentrations with the treatment were still similar or superior in relative to other agricultural residues.