Quinoa germ and starch separation by wet milling, performance and characterization of the fractions

Abstract

Quinoa is a pseudocereal with remarkable nutritional characteristics due to high content of gluten-free biologically valuable protein. The grain is mostly consumed as a whole grain or flour; however, protein fraction is concentrated in the germ, which is external, represents one third of the whole seed and surrounding the perisperm, composed mainly of starch. The aim of this work was to purpose a method for germ and perisperm separation, through a wet milling stage in a roller mill. The method described enables to obtain an enriched fraction of the germ that represents a recovery of 96.5% of the proteins, 95.8% of lipids and 92.6% of ashes, with respect to the germ manually extracted. Additionally, the starch can be recovered in a further step. The extraction yields, nutritional losses and characteristics of the different fractions are discussed.