Variation in the content of nutrients in oats and its relevance for the production of cereal products

Abstract

Oat for cereal production needs to fulfil several requirements including the processing properties and permissible amounts of residues and contaminants. Recently, requirements regarding the content of nutrients have been added. This study gives an overview over the variation of the content of nutrients in oat and their relevance on the manufacturing of oat products. Representative samples of commercial oat lots from Germany, Finland, Sweden, Great Britain and Australia harvested between 1995 and 2002 have been investigated. Furthermore, oat samples of variety trials performed by the Agricultural Board of Schleswig-Holstein and Niedersachsen were included. Among others, the content of oat kernels in protein, fat, beta-glucan, vitamin E and thiamine were determined. The protein content of oat varies between 12 and 17 per cent/dm. In some cases a minimum protein content of oat products of 12 per cent is required. The fat content ranges from 6 to 10 per cent/dm. For the production of rolled oats larger contents are particularly suitable while lower values are advantageous for the production of extruded oat products. The amounts of free fatty acids and peroxides should be low to improve storage life of the oat products. The beta-glucan content of oat is 3,6 to 5,1 per cent/dm. For the production of oat products with cholesterol reducing activity larger concentrations of beta-glucan are to be prefered. The vitamin E content of the oat samples also varies significantly. The ratio mg alpha-tocopherol-equivalents/g diene acid equivalents is of major relevance in terms of nutritional quality. Low vitamin E contents indicate an exceeding storage time or inappropriate storage conditions (Hampshire 2003). The content of oat in thiamine is influenced by the farming system (conventional or organic farming) used and also by the oat variety and the growing site. For the production of certain dietary foods minimum levels of thiamine have been defined. Hampshire, J. 2003. Deutsche Lebensmittel-Rundschau 99: 222-231.