• Naked oats showed high protein variability but consistent, lysine‑rich AA profiles • No association was found between bound phenolics and arabinoxylan • Tempering moisture had a significant effect, while longer tempering had no benefit • Cryogenic milling affected particle size only, but not nutrient distribution • Fractionation remained consistent across roller‑mill scales The demand for low-processed oat ingredients continues to rise, driven by the interest in health‑oriented foods. Compared to hulled oats ( Avena sativa ), naked oats ( Avena nuda ) offer certain nutritional advantages and obviate the dehulling step, thus providing an energy‑efficient alternative for the production of tailored oat fractions. In this study, twelve oat cultivars were characterised with respect to their nutritional and functional properties. This was followed by a systematic evaluation of roller milling performance and tempering conditions both at laboratory and pilot scale, on the distribution of key ingredients in bran fractions. The cultivars exhibited significant compositional variation in the content of protein, fat, starch, dietary fibre, arabinoxylan and phenolic acids, while the amino acid profile remained similar. Short tempering to 11 – 12% moisture for 20 min at room temperature enabled the most effective separation during roller milling, whereas higher moisture (15%) or extended tempering (18 h) decreased yield without improving fractionation. Cryogenic milling mainly altered particle size, while composition remained largely unaffected. Scale up confirmed the robustness of the tempering conditions. Utilizing a bran finisher effectively removed adhering endosperm and further resulted in marked nutrient enrichment, increasing total dietary fibre from 17% to 30%, β-glucan from 3.8% to 9.5% and protein from 15% to 23%, while reducing starch from 60% to 30%. These findings demonstrate that the combination of cultivar selection and controlled processing enables the production of specific, nutrient dense oat bran, which facilitate application in baking and other health-driven food formats.
Hoefler et al. (Fri,) studied this question.