All About Gluten
What Is Gluten
Gluten is a general name for the proteins found in wheat, rye, and barley.
Other gluten containing varieties in the wheat family include wheat berries, durum, emmer, semolina, spelt, farina, farro, graham, kamut, einkorn, and triticale.
Gluten is made up of two sub-proteins: glutenin and gliadin that are found in the endosperm (a type of tissue produced in seeds that are ground to make flour) and nourishes plant embryos during germination.
As an ingredient, gluten forms strands which strengthen dough and create pockets which trap the air released from leavening agents such as yeast. Gluten helps foods maintain their shape.
Gluten acts as a glue that holds food together. Gluten can be found in many types of foods, even ones that would not be expected.
What Grains Have Gluten
Wheat, rye and barley all contain gluten and are forbidden on a gluten-free diet.
Wheat flour is milled from the seeds of the wheat plant (wheat berries) and contains starches, proteins and fats. The two main proteins in wheat are glutenin and gliadin. Glutenin is a very large, loosely coiled protein. It provides the strength and elasticity of the dough, allowing it to bounce back after it has been pulled. Gliadin is a much smaller and tightly coiled sphere that provides stretch for the dough.
The Structure Of Wheat
Bran – the hard outer layer of the wheat kernel which is often removed of the production of refined flour. High in fiber and a small amount of fatty acids.
Endosperm – contains 80% starch and 17% protein. Refined white flour is made from only the endosperm.
Germ – the reproductive part of the seed. It is rich in enzymes, fat, and flavor. The germ is a key component in whole grain flour.
In dry flour, these proteins are lifeless strands wrapped around granules of starch. When they come into contact with water and hydrate, they begin to change shape and the protein strands unwind and begin to link together to form a structural network which is called gluten. The strands of gluten combine to form a membrane-like network. The network engulfs the swollen starch granules and gas bubbles (created by yeast, chemical learners like baking powder or whipped egg whites). The gluten allows the batter to stretch and hold in the gas bubbles as the dough rises and bakes. This gives wheat bread the structure and chewy texture that most people are familiar with.
Rye and barley can also be milled into flour, but are not as common as wheat flour. Barley is more often eaten as a whole grain or added to drinks.
Sources of Gluten
There are many food items that may contain gluten often in hidden or unexpected ways. Always read the label of any food product you buy if gluten-free is not specified on the label.
Pastas: penne, spaghetti, tortellini, dumplings, potstickers, couscous, gnocchi and all pasta not specified gluten-free
Noodles: ramen udon, soba (most are made with a combination of wheat and buckwheat flour), spaghetti, and egg noodles. (Note: rice noodles and mung bean noodles are gluten-free)
Breads: roti prata, bao, croissants, pita, naan, bagels, flatbreads, cornbread, potato bread, rolls, croutons, flour tortillas, panko, breadcrumbs
Pastries: muffins, donuts, croissants
Crackers: pretzels, goldfish, graham crackers, table crackers, water crackers
Baked Goods: pineapple tarts, cakes, cookies, pie crusts, brownies
Cereal & Granola: Always check ingredients. malt extract/flavoring, oats and wheat are all common ingredients.
Breakfast Foods:, pancakes, waffles, french toast, crepes, bagels, cereal, Milo and biscuits.
Sauces: soy sauce, oyster sauce, hoisin sauce, teriyaki sauce, cream sauces made with a roux, any gravy using wheat flour as a thickener
Beer: (unless explicitly gluten-free) and any malt beverages
Snacks: Always check flavoring ingredients in chips, crisps, and any packaged snack.
Processed Foods: Anything processed in a packet can contain gluten. Always read ingredients on the label.
Anything that uses ‘wheat flour’ as an ingredient or simply lists ‘flour’ without specifying the source.