Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/1999
Publication Date: 2/10/2000
Citation: Doehlert, D.C., McMullen, M.S. 2000. Genotype and environment effects on oat milling characteristics and groat hardness. Cereal Chemistry. 77:148-154. Interpretive Summary: Oat bran production involves the dehulling of oats, the heat inactivation of their enzymes and the subsequent grinding and sieving of the clean groats to isolate the larger bran particles. In this study, we determined ways that the variety of oat milled and the environment in which it was grown affects the bran yield and the bran composition. We also investigated properties associated with groat hardness that we postulated to be associated with resistance of groats to breakage and with the bran yield. Bran yield was strongly influenced by groat composition. Bran composition was dependent on a combination of groat composition and bran yield. Groat breakage was most strongly influenced by the environment. Environments where crown rust infections of the oat plants was most severe produced groats most likely to break. Bran yield was not as strongly affected by the crown rust infestation, indicating that bran yield and groat breakage are manifestations of different types of groat hardness and are only partially related.
Technical Abstract: The production of oat bran involves the dehulling of oats, inactivation of their enzymes and the subsequent grinding and sieving of the clean groats to isolate the larger bran particles. The bran yield from the oat groats may be related to their hardness, as it is in wheat. Groat breakage, which occurs during the dehulling process, reduces milling yield and may also be related to groat hardness. This study sought to investigate genotypic and environmental effects on oat dry milling and oat dehulling characteristics, and attempted to define properties associated with oat groat hardness. Significant genotypic differences in bran yield were largely attributed to groat composition, where higher beta-glucan and oil concentrations in the groat were associated with higher bran yields. Bran composition was largely dependent on a combination of the bran yield and the groat composition. Although groat breakage was correlated with bran yield and with groat beta-glucan concentration, environmental factors appeared to be more influential. Locations that had suffered severe crown rust infestations exhibited higher rates of groat breakage during dehulling. Bran yield was not as strongly affected by the crown rust infestation, indicating that bran yield and groat breakage are manifestations of different types of groat hardness and are only partially related.