Hulls

The tough outer coverings of certain grains, seeds, and fruits — such as oat, barley, rice, and almond hulls — that are removed during processing. Though inedible as food, hulls are far from waste: they serve as animal feed, fibre sources, fuel, and growing media. Their removal is a key step in producing refined cereals and clean, safe kernels, and the efficiency of hull separation affects both yield and product purity. In some crops, such as rice, hulls are also explored as a source of silica and bioactive compounds, extending their value beyond simple by-product status.