THE EFFECT OF DRYING TEMPERATURE ON THE PROPERTIES AND QUALITY OF IMMATURE BARLEY

Abstract

The effect of drying temperature was determined on the properties and quality of straight (direct) combined/artificially dried immature barley (Hordeum vulgare L. ’Harrington’) and compared with traditionally swathed/natural air-dried/threshed barley. Four stages of maturity were investigated ranging in kernel moisture content (KMC) from 56 to 19%. Straight combined samples were dried at temperatures of 20, 35, 60 and 90 °C. The artificial drying temperatures produced similar yields and 1000-kernel weights but the lower temperatures produced larger test weights for grain straight combined at 56% KMC. Small reductions in crude protein, crude fat and ash content occurred for the most immature barley when the higher drying temperatures were used. Plumpness, germination and other malting qualities decreased with increasing KMC and artificial drying temperature. Except for a little higher yield for the straight combined barley, both harvesting methods usually produced barley with similar physical properties and composition when the KMC was about 40% or less and the artificial drying temperatures did not exceed 35 °C. Swathing provided barley with the best germination and malting quality when the KMC exceeded 20%.Key words: Barley, drying, harvesting method, quality, immaturity, kernel moisture content