Process for fractioning grain flour into components of food quality

摘要

The present invention is concerned with a process by means of which the fraction of grain flour that remains after separation of the main part of the starch in the grain flour, and possibly of the gluten-type protein, which remaining fraction contains 15 to 40 per cent by weight of the dry substance of the grain flour, depending on the species of grain, is divided into two products of food quality, one of these products comprising a 20 to 35 percent-by-weight fraction of the dry substance, consisting mainly of the albumin-globulin-type proteins soluble in water of the grain, and the other one, a syrupy product, consisting mainly of sugars obtained as products of hydrolysis of small-particle starch of grain. By means of the process, grain flour can be fractioned into three, in the case of certain flour species, four, industrially usable products, which are ordinary grain starch, gluten in the case of certain grains species, syrup obtained from small-particle starch, and soluble proteins, so that no waste or waste waters are produced at all. According to the invention the homogenous slurry obtained after separation of ordinary grain starch and gluten from the grain flour by known methods and containing 15 to 40 per cent by weight of the dry substance of the grain flour, is heated at a temperature of at least 120°C, treated at a temperature of at the most 90°C simultaneously by means of alpha-amylase and beta-glucanase, the produced precipitate, containing at least 40 per cent by weight of protein, as calculated from the dry substance of the precipitate, is separated from the sludge, washed, and dried, the remaining clear fraction is sugared by means of amyloglucosidase or fungalamylase at a temperature of at the most 55°C until the dextrose equivalent (DE) of the sludge is at least 20, and the syrup obtained is, if necessary, concentrated by evaporating water.