Starch for food purposes; nutritional supplements made of starch and starch products; food preparations made of starch fibres with a high roughage content for processing in bread, pastry and confectionery, namely, starch-based binding agents for ice cream, starch-based thickeners for whipped cream and starch-based candies; food preparations, namely, food starch made of starch fibres with a high roughage content in the form of thickeners and binders for the processing of sausage products