Wheat starch sepn into first and second grades - with improved water recycling

摘要

Prodn. of wheat starch comprises mixing wheat flour with water, washing the resulting dough with water, sieving the resulting crude starch milk and classifying it into the first grade starch milk and the second grade starch milk contg. some first grade starch. The second grade starch milk is evaporated and the vapour is condensed and recycled. High degree of water recycling is achieved. The efficiency of the entire process is improved. Besides the first grade starch, a starch mixt. is obtd. contg. some natural and decomposed starches of the first and the second grade, water-soluble components of wheat flour esp. proteins and pentosan, mineral substances, B-complex vitamins raw fibres and residual gluten. This mixt. can be used as a food additive, e.g. baking aid, in pharmacy etc. The effluents are reduced to 2.5 m3/ton of wheat flour; they are non-toxic and do not contain any settling impurities; their oxygen demand does not exceed 200.