Optimization of β-glucan levels in different oat fractions by milling and air classification

Sammanfattning: Oat (Avena Sativa) is an important crop worldwide which is mostly due to its various characteristics and nutritional profile. The recent progression in food nutrition have shown the importance of the different components in oats. Many health benefits of oats are attributed to β-glucan which have been demonstrated and well-studied over the years. This investigation is part of a project commissioned by Lantmännen that has for a long time pursued plant breeding of oats and invested in research and de-velopment. The aim of this project was to investigate if there is a potential to obtain a fraction from oat with high levels of β-glucan. Air classification and sieve analysis were utilized for β-glucan enrichment from a pre-fractionated oat fraction with 20 % β-glucan. Effects of speed of the classifying wheel, size of particle and different mill-ing settings on the β-glucan separation efficiency were evaluated. To better under-stand the separation efficiency between the fine and coarse fractions, both particle size distribution analysis and scanning electron microscopy were performed. Through optimization of milling and air-classification parameters, a β-glucan content up to 26.9 % could be obtained. Results indicate that air classification is a good method to use for enrichment of β-glucan from oats and prevents breakdown of the β-glucan molecule. The ability to enrich β-glucan level can increase the economic value of oats and possibility to tailoring fraction for specific markets in the food in-dustry and lead to new product development. It can be concluded that in the near future there will be health-promoting products in the market where β-glucan content is increased