GLUTEN AND CELIAC DISEASE: Understanding the Reasons

[WHAT IS GLUTEN?]

Gluten is the protein component found in cereals, primarily in soft wheat flour and durum wheat semolina. It is also present in flours such as spelt, barley, and rye. In soft wheat, the most commonly used cereal in breadmaking, the protein content in flour varies between 8% and 18%. This variation depends on the type of seed cultivated, the region of cultivation, and the farming techniques used.

Among all the proteins present, two are particularly important for the leavening process and the final result of bread or other baked goods:

  • Gliadin: An insoluble protein composed of small, globular molecules. It forms a pasty mass that gives gluten its plastic properties.
  • Glutenin: An insoluble protein made up of large molecules linked by disulfide bonds formed during kneading. Glutenin contributes to the dough's consistency during baking, enhancing its stability.

During mixing and kneading, gluten formation occurs, creating the so-called gluten network, which is essential for providing the proper texture and functionality to bread, pizza, pasta, and various baked goods. The hydration and mixing of gliadin and glutenin result in bonds that form an elastic, gummy substance, which provides strength and structure to the dough. These bonds, known as disulfide bonds, are key to the dough's performance.


[WHAT IS THE FUNCTION OF GLUTEN IN BREAD OR PASTRIES?]

The main function of gluten is to form the gluten network. This elastic film forms within the dough, trapping gases produced during fermentation. During baking, gluten proteins coagulate (solidify), creating an external semi-rigid structure that provides firmness while the interior remains soft.

The amount and ratio of gliadin and glutenin in flour influence the final product's:

  • Structure
  • Volume
  • Appearance

Depending on the amount of gluten, different types of baked goods can be achieved:

  • Low gluten content: Suitable for shortcrust pastries and tart bases.
  • Medium-low gluten content: Ideal for common or artisan bread and sponge cakes.
  • Medium-high gluten content: Used for puff pastry or specialty breads.
  • High gluten content: Required for light, airy breads like rolls or rich desserts like panettone and colomba.

In Italy, local soft wheat flours typically have a moderate gluten content. To achieve higher levels, they are often blended with wheat varieties imported from countries like Canada or Australia, which naturally have higher gluten content. Flour made from such grains is known as Manitoba flour (see article “Bread at home”).


[HOW IS GLUTEN MEASURED?]

In milling, the percentage of gluten is indirectly indicated by the "W" value. A higher "W" value corresponds to a higher gluten content.

The alveograph measures this value, which is typically around 230-260 W for standard flour.

Additionally, the gluten ratio can produce dough with varying elasticity or rigidity, depending on the proportions of gliadin and glutenin. This balance is measured by the P/L ratio (elasticity/tenacity), also determined with the alveograph.

Ideally, the P/L value should be around 0.5:

  • Below 0.5: The dough is too elastic and risks collapsing during baking.
  • Above 0.5: The dough is too rigid and results in poor leavening and overly crusty bread.


[CELIAC DISEASE]

An increasing number of people suffer from celiac disease, a condition triggered by the presence of gluten in foods. It is caused by an autoimmune reaction to gluten.

Celiac disease is a chronic inflammation of the small intestine characterized by the destruction of its mucosal lining. Upon exposure to gluten, the immune system attacks the intestinal lining, damaging the villi responsible for nutrient and mineral absorption.

Symptoms include chronic diarrhea, abdominal pain, bloating, and vomiting. In young children, it can lead to weight loss or failure to thrive. However, it is important to clarify that celiac disease does not cause life-threatening reactions like anaphylactic shock since it is not an allergy.


The exact triggers of celiac disease are not yet fully understood. The most common theory is a genetic predisposition, often manifesting in adulthood. There is also speculation that genetically modified grains (GMOs) could play a role. Celiac disease affects about 1% of the population and is more common in women than in men.

Currently, there is no cure for celiac disease. The only effective solution is to adopt a gluten-free diet, avoiding all gluten-containing foods, including unexpected sources like sauces, processed meats, and canned soups. This requires careful reading of product labels or purchasing from specialized stores. By eliminating gluten, symptoms can be avoided, and existing damage to the intestinal lining will heal over time.