Gluten is found in many cereals, such as wheat, spelt, rye and barley, and serves as a storage protein for plants. In coeliac disease patients, however, it triggers an inflammatory response, leading to intestinal damage. Even traces of gluten are toxic.

Gluten is the generic term used for the family of storage proteins found in wheat rye and barley. Gluten proteins are found, conjoined with starch, in the endosperm of the grain seed. They make up approximately 5 – 10% by weight of the dry grain matter and thus around 80% of the total grain protein. Gluten is an adhesive protein and has various food-technological properties. Gluten itself has a low nutritional value but is a good emulsifier and flavour carrier; it gels, binds water and acts as a stabiliser. Gluten is therefore versatile when used in convenience foods and sauces, as well as an additive in food technology.

Gluten is soluble in alcohol and can be divided into prolamins and glutelins.

Wheat prolamins are called gliadins, while wheat glutelins are called glutenins.

Only prolamins, the alcohol-soluble protein fractions of the following grains, are toxic to persons with coeliac disease:

• Wheat (gliadin)
• Barley (hordein)
• Rye (secalin)
• Botanically related species, e.g. as spelt, green spelt, kamut, emmer and einkorn

Digestion of prolamins

Prolamins are rich in proline and glutamine, two amino acids that are difficult to digest. Neither proline or glutamine are classified as essential amino acids. It is the high proline and glutamine content in gluten that prevents the proteins from being completely broken down by the digestive enzymes. The long-term result of this is that toxic oligopeptides, proteins with up to ten amino acids, are present in the small intestine. Proline is degraded using an oxidase, which converts proline into glutamic acid using glutamate-gamma-semialdehyde. The glutamic acid in turn must be converted into glutamine, so that it can be transported to the brain, where it is necessary for protein synthesis.

Oats

The prolamin found in oats (known as avenin) is not believed to be toxic to the majority of coeliac patients. However, there is a high risk that standard oat products may be contaminated with gluten and should be avoided. Current advice from the National Institute of Clinical Excellence states that patients can choose to include gluten free oats in their diet at any stage and will be advised whether to continue eating gluten free oats depending on their immunological, clinical or histological response.

Gluten-free flours: properties and uses in the kitchen

Knowing gluten-free flours is a top priority when starting a gluten free diet. Alternative flours allow you to make fragrant and delicious bread, pizza and desserts just like the classic ones. However, it is important to know the characteristics of each one, in order to be able to use them in the kitchen to the fullest.

To make the task easier for you when you shop, avoiding doubts in front of the super shelf, here is a list of gluten-free flours. They are divided into three groups based on their derivation from cereals, pseudocereals and dried fruit and legumes. Each flour is then analyzed individually on the basis of nutritional properties, characteristics and the most suitable uses in the kitchen.

Gluten-free flours derived from cereals

• corn flour
• rice flour
• millet flour
• teff flour
• sorghum flour

Gluten-free flours derived from pseudocereals

• buckwheat flour
• quinoa flour
• amaranth flour
• sativa hemp flour

Gluten-free flours derived from dried fruit and legumes

• almond flour
• hazelnut flour
• Chestnut flour
• chickpea flour
• lupine flour

1 – The nutritional properties of gluten-free flours derived from cereals

Corn flour: together with corn flour, it is the best known gluten free flour used in the kitchen. It is obtained by grinding the grain of maize and has a sweet and rustic flavor. Mixed with other gluten-free flours, it gives friability to doughs for desserts, pizzas and breads. There are many varieties, including bramata, white corn, foil, etc.

Rice flour: on the market it can be found in many varieties, from white to wholemeal, with more or less fine grain, depending on the type of grinding. It is ideal for preparing almost all gluten-free recipes, from pasta to biscuits, from pizza to desserts that need particular softness. It can be a good base for soups and batters.

Millet flour: obtained by grinding the grains of millet, a plant classified as a minor cereal. It is a gluten-free flour with a delicate flavor, very rich in vitamins A and B. It is suitable for the preparation of crepes, pancakes and wet desserts (banana bread), in which it can also replace up to 30% of the total amount of flour. There are two varieties on the market: golden millet (light color) and wild millet (brown color).

Teff flour: obtained from a microscopic grain, it is a wholemeal flour with a rather sweet taste. It is used in the recipes of short crust pastry, shortbread, biscuits, pancakes and bread, in which it can replace up to 25% of the total flour.Sorghum flour: with a delicate, light and neutral flavor, it is obtained from the seeds of an African plant, the cob of sorghum (in particular the white one). Also known as “durra flour”, it is a precious source of vitamins, mineral salts and fibers and is indicated in both sweet and savory recipes

2 – The nutritional properties of gluten-free flours derived from pseudocereals

Buckwheat Flour: Not everyone knows that buckwheat is not a cereal, but a plant belonging to the rhubarb family. With a robust, toasted and slightly bitter flavor, in traditional cuisine it is the basis of various preparations, such as pizzoccheri from Valtellina, Russian blinis and Japanese soba noodles. Even in gluten-free cooking this flour is suitable for making fresh pasta and bread (if mixed with other gluten-free flours), crepes and desserts.

Quinoa flour: with a flavor reminiscent of legumes, it is also on the market in the toasted version. It is a very versatile ingredient, rich in proteins and with a low glycemic index, ideal for savory recipes, especially breads. It can be used alone or mixed with other flours.

Amaranth flour: obtained from the tiny seeds of Amaranth, a plant of Central American origin, it is very rich in essential amino acids among which lysine, which is not found in other cereals, stands out. It is a flour with a strong, almost toasted flavor, reminiscent of the flavor of dried fruit and malt. It is excellent with rice flour or quinoa flour, and should be mixed carefully in bread and pizza doughs.

Sativa hemp flour: it is obtained from Cannabis sativa (free of psychotropic substances) and is particularly protein, therefore suitable in the diet of athletes. Mixed with other gluten-free flours, it gives a vaguely nutty aftertaste to preparations. It can be added to sauces, smoothies and ice creams, or taken dissolved in water.

3 – The nutritional properties of gluten-free flours derived from legumes and dried fruit

Almond flour: derives from the processing of almonds. It can be easily obtained at home by grinding almonds in a blender with sharp blades for nuts or coffee beans. It contains few carbohydrates but is a precious source of vitamin E and monounsaturated fats. Plus, it has a low glycemic index. But… watch out for calories! Its sweet and robust flavor makes this flour very suitable for the preparation of desserts.

Hazelnut flour: obtained by grinding the Tonda Gentile delle Langhe (synonym Trilobata) , or Piedmont Hazelnut variety. Low in carbohydrates, like that of almonds, it is rich in vitamins (A, C, E and group B), mineral salts and fiber. It is particularly suitable for making sweets, creams and ice creams.

Chestnut flour: obtained from the grinding of previously dried chestnuts. An ingredient already known in Italian cuisine, because at the base of specialties such as castagnaccio (chestnut cake), it is rich in complex carbohydrates and starches, and has a high caloric intake.

Chickpea flour: it is a source of fiber and precious nutrients. Although it has a sweetish taste, it is often used for savory preparations (meatballs, farinata, panelle, etc.). It is also used for browning and frying.

Lupine flour: the legume from which this gluten-free flour is obtained is among the richest in proteins (16.4 g per 100 g of product, a quantity greater than that of eggs). It is recommended in the preparation of baked, sweet or savory products.

It is always advisable to make sure that the symbol of the crossed ear or the claim “gluten-free” appears on the packaging of naturally gluten-free flours, because they can be subject to the risk of cross-contamination during processing.

4 – Forbidden flours: the most common ones containing gluten

To conclude (and dispel any doubts!) It is good to do a little review of the flours prohibited in the gluten-free diet, namely:

• wheat flour
• spelled flour
• kamut flour
• Rye flour