Summary
Residues obtained from the juice industry have been underused, wasting a product that might present potential to be included in food for humans. Thus the objective of the present study was to carry out microbiological and nutritional compositional analyses of the flours made from grape, apple, orange and acerola juice residues, with different granulometries. The juice residues were obtained by donation from an industry in Bento Gonçalves (RS/Brazil), dried and ground in order to obtain flours with different granulometries (>0.600, 0.600 mm, 0.425 mm, 0.300 mm and ≤0.250 mm). The flour samples were submitted to an analysis of the proximate composition, acidity, pH, °Brix and total polyphenols. The microbiological analysis consisted of enumerating heat tolerant coliforms and testing for the presence of Salmonella spp. The results indicated satisfactory microbiological quality. The proximate composition showed that granulometry influenced the nutritional values of the flours and that the energy values of flours obtained from acerola, orange and grape residues were inversely proportional to the particle size. All the flours analysed could be considered rich in fibres, with values varying from 11.2% to 54.5%. The grape and acerola flours presented higher protein levels – from 8.2% to 15.6% and from 8.3% to 12.1%, respectively – and the orange and grape residue flours presented high levels of total polyphenols. Thus the use of such residues in human nutrition can be recommended, improving the nutritional value of food preparations.
Key words:
Industrial residues; Polyphenols; Dietary fiber; Whole food use