Genetics, characteristics, and utilization of oil in caryopses of oat species

Abstract

Abstract For oats to be an economically feasible oilseed crop in Iowa, the oil percentage would have to be increased to ca. 16%. A survey of the oil percentage in 445 oat cultivars and collections gave a range of 2.0–11.0%. The oil percentage was only slightly affected by growing oats in 5 different locations in Iowa. Inheritance studies indicated that oil percentage was inherited polygenically, and there was a tendency for high oil percentage to be partially dominant. Analysis of 64 cultivars and collections showed a wide variation of fatty acid composition: palmitic, 14–23%; stearic, <1–4%; oleic, 29–53%; linoleic, 24–48%; linolenic, < 1–5%. The oil percentage was positively correlated with oleic acid and negatively correlated with linoleic and linolenic acids. Oats contained a lipase that made extraction of oil with low acid values difficult. The lipase was strongly affected by moisture and was most active in oat doughs containing 25–50% moisture. There was at least a 20‐fold variation in lipase activity in oat cultivars and collections. Whole oats may be kept in dry storage for several years without significant lipolysis, but in broken or crushed caryopses, lipolysis occurs even at low moisture levels. The lipase may be inactivated by heat or 95% ethanol treatments.