Bread belongs to those foods that form the basis of all civilizations’ diets due to its nutritive value, its low price, and the simplicity of using its primary ingredient, the cereals, for culinary purposes. Cereals belong to the family of Gramineae, which are characterised by seed and fruit forming the same structure: the grain. Therefore, the term “cereals” comprises the Gramineae plants (Poaceae Family) and their ripe fruit (unspoilt, dry and as a whole (Martín et al., 2007).
Since prehistoric times, bread has been a staple food in man’s diet. Probably, the first breads were made with acorn or beechnut flour. It is known that Egyptians prepared bread and it is thought that they discovered fermentation casually.
The term bread designates the ‘perishable food prepared by cooking a dough of wheat flour, water and salt, fermented by specific microorganisms, typical of bread fermentation, such as Saccharomyces cerevisiae’. When other cereals are used to prepare the flour, the bread is named with the corresponding type of cereal used (for example, rye bread, corn bread, etc.) (Ávila et al., 2007).
Bread is rich in complex carbohydrates (starch being the major component), it has a high content of plant proteins, and hardly contains fat. It is a good source of B vitamins and minerals such as phosphorus, potassium, and magnesium. Due to these nutritional properties, it comes as no surprise that nutrition experts define bread as an essential part of the food pyramid’s base, as it should also constitute the base of the diet (in countries where bread is a staple source of carbohydrates), the way it has been for the majority of cultures over the course of human history (Incerpan, 2007).
Bread: a source of carbohydrates
In a balanced diet, at least 50% of total calories of diet should come from carbohydrates, which are needed to provide our body with energy to function and develop correctly.
Bread contains on average 50-60 g of carbohydrates, mainly as starch (a part of which is resistant starch, which is a type of carbohydrate of slow absorption) (Salvador, et al., 2001). Starch is the main component in the wheat grain, accounting for two thirds of it. Other polysaccharides such as cellulose, hemicellulose, lignin and pentosans are also present but in lower amounts. Bread also contains dextrins, maltose and glucose, which are starch breakdown products.
Bread and fibre
Fibre in cereals is concentrated in the bran, which is removed to obtain white flour for the production of white bread (the most consumed bread in developed countries). Consequently, the fibre content is much higher in whole grain breads than in white breads, approximately from 2 to 6 times higher.
Whole grain breads are made with flour produced from whole cereal grains, except for the most external layer. In the bread-making process, fibre increases water absorption, the time of dough development and the kneading resistance. Fibre also lowers the retention capacity of gas and therefore the bread volume, and it darkens the crumb.
Although fibre is not a nutrient, its consumption is necessary because it has numerous benefits for health. The most well-known benefit is that it helps intestinal transit. The fibre found in bread is insoluble, so it produces a bigger laxative effect.
Essential vitamins and minerals in bread
Bread provides water-soluble vitamins of the B group, which our body has little capacity to store, as well as numerous minerals that our organism needs to function properly. For this reason, we have to ensure their intake through our daily diet in order to cover our body’s needs.
Specifically, bread contains vitamin B1 or thiamine, vitamin B2 or riboflavin, vitamin B3 or niacin, vitamin B6 or pyridoxine and vitamin B9 or folic acid. With respect to minerals, it contains large amounts of phosphorus, magnesium, calcium and potassium, and in lesser quantities others such as sodium, iron, or iodine.
Both vitamins and minerals are concentrated in the bran and in the germ, parts that are removed during the milling. In consequence, white bread has a much lower content of vitamins and minerals than whole grain bread. This is another reason, together with the higher content of fibre, why it is recommended to increase the consumption of whole grain bread (Incerpan, 2007).
Composition and nutritional value
Table 1: Macronutrient content of some types of bread (per 100 g)
| Type of bread | Energy (kcal) | Water (g) | Protein (g) | Lipids (g) | Carbohydrates (g) | Fibre (g) |
| White bread | 261 | 34.9 | 8.5 | 1.5 | 51.5 | 3.5 |
| Toasted white bread | 262 | 37.5 | 6.8 | 4.4 | 46 | 5.3 |
| Rye bread | 230 | 40.5 | 6.2 | 1 | 45.8 | 6.5 |
| Sliced bread | 272 | 34.9 | 7.9 | 3.8 | 49.9 | 3.6 |
| Whole grain bread | 259 | 36.1 | 10.9 | 3 | 44 | 6 |
| Hamburger bread | 271 | 36.2 | 7.5 | 4.7 | 47.5 | 4.1 |
Source: Ortega R, López AM, Requejo AM, Carvajales PA.
Table 2: Micronutrient content of some types of bread (per 100 g)
| Type of bread | Ca (mg) | Fe (mg) | Mg (mg) | Zn (mg) | Thiamine (mg) | Riboflavine(mg) | Niacin (mg) |
| White bread | 56 | 1.6 | 25.1 | 0.61 | 0.086 | 0.06 | 3 |
| Toasted white bread | 114 | 1 | 25 | 0.78 | 0.36 | 0.27 | 6.2 |
| Rye bread | 29 | 2.4 | 35 | 1.2 | 0.18 | 0.11 | 3 |
| Sliced bread | 91 | 2.3 | 21.9 | 0.5 | 0.2 | 0.05 | 3.1 |
| Whole grain bread | 99 | 3.8 | 58 | 1.4 | 0.35 | 0.33 | 6.7 |
| Hamburger bread | 211 | 2.3 | 34 | 1.8 | 0.32 | 0.14 | 2.5 |
Source: Ortega R, López AM, Carvajales PA.
Conclusions
Many false beliefs exist around nutrition and food habits and in the case of bread (and other staple carbohydrate food sources), the popular myth is that it should be one of the principal components to eliminate or restrict when being on a weight loss diet. This false belief according to which carbohydrates make you fat and lack nutritional importance, has caused bread consumption to fall far behind the World Health Organization (WHO) recommendations to eat bread several times a day. A number of European countries recommend a daily bread intake of about 250g, which corresponds to 4-8 slices depending on national food habits (World Health Organization, 2003).
Taking into account its nutritional value, bread should constitute a vital part of the diet (in countries where bread is the major carbohydrate staple), ideally being present in all meals from breakfast to dinner. Not consuming bread habitually contributes to an unbalanced calorie intake because the amount of calories coming from foods high in fat or protein would increase, thus deviating from the recommendations for a balanced diet, where 50-55% of total calories should come from carbohydrates, 10-15% from proteins and 30-35% from fat. Therefore, bread should be a regular part of everybody’s diet. Only people that suffer from coeliac disease or gluten intolerance (gluten is a protein found in wheat and other cereals like rye, barley and oats) need to substitute it by other varieties (e.g. corn bread), which are free of gluten.
References
- Ávila, J. M., Beltrán, B., Cuadrado, C., del Pozo, S., Rodríguez, M. V., Ruiz, E. La Alimentación Española: características nutricionales de los principales alimentos de nuestra dieta. Ministerio de Agricultura, Pesca y Alimentación, 2007.
- Dossier de prensa de la campaña “Pan cada día”. Incerhpan, 2007.
- Martín, E., de Mateo, B., Miján, A, Pérez, A. M., Redondo, P., Sáenz, I. Pan y Cereales. Dirección General de Salud Pública y Alimentación. Comunidad de Madrid, 2007.
- Salvador, G., Bultó, L. Larousse de la Dietética y la Nutrición. Spes Editorial, 2001.
- World Health Organization. Food based dietary guidelines in the WHO European Region, 2001. www.euro.who.int/Document/E79832.pdf
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