The role of total lipids and fatty acids profile on the water uptake of barley grain during steeping

Abstract

Steeping is the first operation of malting and its overall purpose is to increase the water content of the grain, as well as to activate the enzymatic pool in the endosperm. The aim of this study was to evaluate the effects of total lipids content and individual fatty acids on water uptake, by commercial barley varieties. The results from this study showed that unsaturated fatty acids, such as oleic acid (18:1-n9), have a role in controlling water uptake by the barley endosperm during steeping. When partial least squares (PLS) regression was used to relate total lipids, individual fatty acids and water uptake, oleic (18:1-n9) acid had a positive effect, while long chain unsaturated fatty acids such as arachidic (20:0) and lignoceric (24:0) acids had a negative effect on explaining 72% of the total variability in water uptake. Water uptake by the endosperm is just a component of the system that is responsible for the overall malt quality properties and chemical characteristics of a given material. In this context, both total lipids and individual fatty acids have a role on determining malt quality in barley.