Processing of oats: Structure, composition and milling

It has overview of oats processing

1. Processing of Oats

2. Introduction to Oats Oats (Avena sativa) are cereal grains primarily cultivated in temperate regions. They are valued for their nutritional quality, rich in soluble fiber (β-glucan), protein, fat and minerals. Oats are used for human food, livestock feed, and industrial products.

3. Nutritional Composition Oats contain approximately: • Carbohydrates – 66% (Dietary fiber- 12%; -glucan- 4%) • Protein – 1 7 % • Lipids – 7% • Minerals – Calcium, Iron, Phosphorus These nutrients contribute to the health benefits of oats.

4. Uses of Oats Rolled oats for porridge and breakfast cereals Instant oats and oat flour for bakery products Oat bran as a dietary supplement Oat hulls used as animal feed and fuel

5. Oat Grain Structure Oat grains consist of hull (outer layer), bran, endosperm, and germ. The hull is inedible and must be removed during processing. The groat (dehulled oat kernel) is the main edible part.

6. Processing Objectives • Remove foreign matter and impurities • Dehull oats to obtain groats • Inactivate enzymes to prevent rancidity • Improve flavor and texture • Produce different oat products (flakes, flour, bran)

7. Flow Chart of Oat Processing

8. Cleaning and Grading Oats are cleaned using air aspirators, sieves, and magnetic separators to remove dust, stones, and other impurities. Grading ensures uniform kernel size for efficient dehulling.

9. Dehulling Dehulling removes the outer hull using impact dehullers. The hulls are separated from groats by air classification or sieving. Efficient dehulling minimizes kernel breakage.

10. Kilning (Heat Treatment) Oat groats are heat-treated or 'kilned' at 90–100°C to inactivate lipase enzymes, stabilize fat, and develop a nutty flavor. Kilning also improves milling characteristics.

11. Cutting and Sizing Groats are cut into smaller pieces using steel cutters to produce 'steel-cut oats'. Cutting size determines final product texture.

12. Rolling and Flaking Cut or whole groats are steamed and rolled into flakes using heavy rollers. Flake thickness affects cooking time and texture — thick flakes for traditional oats, thin flakes for quick oats.

13. Drying and Packaging After rolling, oats are dried to a safe moisture level (around 10–12%) and packaged in moisture-proof materials to ensure shelf stability.

14. By-products and Utilization Oat hulls are used for animal feed, biomass fuel, or extraction of xylose. Oat bran and germ fractions are valuable for functional food formulations.

15. Recent Technological Advances • Enzyme stabilization using infrared heating • Extrusion cooking for instant oats • Oat protein and fiber fortification in beverages • Gluten-free oat processing innovations.

16. Additional Slides