Oat vary among oat varieties. Also, oats products are frequently cross-contaminated with other gluten-containing cereals during grain harvesting, transport, storage or processing. Pure oats contain less than 20 parts per million of gluten from wheat, barley, rye, or any of their hybrids. Use of pure oats in a gluten-free diet offers improved nutritional value from the rich content of oat protein, vitamins, minerals, fiber, and lipids, but remains controversial because a small proportion of people with celiac disease react to pure oats. Some cultivars of pure oat could be a safe part of a gluten-free diet, requiring knowledge of the oat
Wheat gluten (food) observed a week of vegetarianism each year. "Miàn jīn" is often deep fried before being cooked in Chinese cuisine, which confers a crispy rind that enhances the texture of the gluten. There are three primary Chinese forms of wheat gluten. Oil-fried gluten (, "yóu miàn jīn") is raw gluten that has been torn into small bits, then deep-fried into small puffy balls of around 3–5 cm in diameter and sold as "imitation abalone". They are golden brown in color, and braised or boiled in a savory soup or stew before eating. They are frequently paired with "xiang gu" (black mushrooms).