3. Quality and recipes

3.4. The nutritional value of bread

Cereal grains are the principal crops which have made the continuation of mankind possible. Except for the rice-eating peoples, the principal products of cereal crops have been some form of bakery foods. The great contribution of the Egyptians to food development was in bread making - they produced at least 40 varieties. This variety came not only from using yeast, but also from blending various kinds of cereal grains to make breads differing in texture. Bread was so basic to most people's diets by Roman times that the word was a synonym for food. The role of bread in the maintenance of life and limb is recognized in the English description (1638) that "bread is the staff of life". One is tempted to speculate upon whether the decrease in the domestic consumption of the food we call the "staff of life" may somehow be associated with the increasing prevalence of obesity and possibly other diseases, and our decreasing national productivity. The image of bread as "starchy" or "fattening" is, ironically, contrary to the unique role of cereal grain foods in the history of man.

Governments all over the world have health campaigns. In these campaigns always advocates one of the following recommendations

  1. To avoid overweight, consume only as much energy as is expended; if overweight, decrease energy intake and increase energy expenditure.
  2. Increase the consumption of complex carbohydrates and "naturally occurring" sugars from about 28 percent of energy intake to about 48 percent of energy intake.
  3. Reduce the consumption of refined and processed sugars by about 45 percent to account for about 10 percent of total energy intake.
  4. Reduce over-all fat consumption from approximately 40 percent to about 30 percent of energy intake.
  5. Reduce saturated fat consumption to account for about 10 percent of total energy intake; and balance that with poly-unsaturated and mono-unsaturated fats, which also should account for about 10 percent of energy intake for a total of 20 percent of calories from fats and oils.
  6. Reduce cholesterol consumption to about 300 milligrams per day.
  7. Limit the intake of sodium by reducing the intake of salt to about five grams per day.

As a result we should:

  1. Increase the consumption of fruit, vegetables and whole grains.
  2. Decrease the consumption of refined and other processed carbohydrates and foods high in simple carbohydrates.
  3. Decrease the consumption of foods high in total fat, and partially replace saturated fats, whether obtained from animal or vegetable sources, with polyunsaturated d fats.
  4. Decrease the consumption of animal fat and choose meat, poultry and fish which will reduce saturated fat intake.
  5. Except for young children, substitute low-fat and nonfat milk for whole milk, and low-fat dairy products for high-fat dairy products.
  6. Decrease the consumption of butterfat, eggs and other high cholesterol sources. Some consideration should be given to easing the cholesterol goal for pre-menopausal women, young women and the elderly in order to obtain the nutritional benefit of eggs in the diet.
  7. Decrease the consumption of salt in foods and foods high in salt content.

Analysis of white flour and wholemeal flour

Before talking about the nutritional value of bread, let's have a look at chemical analysis of white flour and wholemeal flour. Analysis give the following average values:

for 100 g
white flour
wholemeal flour
proteins
11,5 g
12,0 g
carbohydrates
71,0 g
67,0 g
fibre
3,2 g
5,6 g
fats
1,1 g
1,5 g
fytic acid
90 mg
510 mg
calcium
15 mg
24 mg
magnesium
28 mg
65 mg
iron
1,2 mg
2,3 mg
vitamin B 1
110 µg
330 µg
vitamin B 6
100 µg
280 µg
vitamin B 9
16 µg
25 µg
vitamin E
340 µg
950 µg

The proteins in white flour are the gluten of course. With regards to the nutritional value, gluten are not very interesting because they contain little of no lysine, an essential amino acid for humans (70 % less then in eggs for instance). Gluten are also not rich in merdionine and valine, another two amino acid which are important for human beings. White flour also contains much less minerals and vitamins: just compare both analysis and it will be obvious(88 95 % extraction).

Brown bread has always been the favourite for nutritionists. The first 3 - 4 layers of the wheat kernel is an excellent source for all kind of vitamins, fibres and proteins. These layers do contain lysine and are rich in vitamin B and fytic acid that forms chelates with the minerals so these can be assimilated by the human body.

Today nobody doubts anyore that whole grain contains undefined phytochemicals that are discarded when grains are refined. Some of the more common grains are wheat of course but also oats, corn, barley, buckwheat, rye, flax, sorghum, spelt and kamut. Less well known are quinoa and teff. The challenge of incorporating these different grains is maintaining some kind of structure in the baked product and at the same time take advantage of the particular flavour notes they can impart to the bread.

grain
% fibre content
kamut
19,2 %
barley
17,3 %
rye
14,6 %
wheat
12,2 %
oats
10,6 %
buckwheat
10,0 %
sorghum
9,0 %
corn
7,3 %
quinoa
5,9 %

We also forget too easily that these grains can be used as excellent sources of carbohydrates to make particular kinds of sourdoughs. I have seen sourdoughs made from chickpeas, sorghum or where a part of the flour was replaced by potatoes (see chapter on sourdough).

Finally one additional consideration: these different types of cereals can absorb considerable amounts of water, which can be the reason by there is some volume loss of the bread. When too much water is needed to hydrate the dough, the water activity will increase, making the bread more susceptable to mould growth.

The underestimated importance of fibres

Do you like a bowl of muesli for breakfast ? Do you always eat wholemeal bread and do you like fruit and vegetables ? Nutritionists will love this. All these products are rich on nutritional fibres. Those are very important to our body but we are having too few of them. Especially our intestines (bowels) suffer from the lack of them.

Being healthy or not has a lot to do with our nutrition. A balanced nutrition contains all the needs for a good functioning. Vitamins, proteins, minerals, fats, carbohydrates (sugars, dextrins and starch). We know all these substances. Nutritional fibres are at least as important, but it is less known that they are of great importance to our body. And don't think that breakfast cereals are healthy: rice krispies or frosted flakes are full of sugars and fats. If you want to eat healthy have a slice or two of wholemeal bread in the morning. On top of that bread is much cheaper then all the breakfast cereals. Just calculate the price per kilogram and you will be surprised.

What is a nutritional fibre ? Most of us think it is as thready as the fibres of a piece of textile. This is not the case. Blackberries for instance contain a lot of nutritional fibres and they are not thready at all.

A nutritional fibre is that part of the plant we cannot digest. It is a general term for different substances which are located in the cell-wall of plants. Fibres provide firmness to the plant and damp absorption in the plant. More or less the same occurs in our body. Because fibres don't digest and retain fluid, they give volume to the content of the stomach and the intestines. They promote the bowel transit. For people who are having bowel problems, such as slow motion, haemorrhoids or constipation, fibre rich food is often sufficient to solve a large part of the problems.

Nutritious fibres are only found in plants. Eggs, cheese, milk, fish or chicken contain none. The most important sources of nutritious fibres are rye bread, wholemeal bread, vegetables, fruit, brown rice, nuts and white beans.

Nutritionists make a difference between 2 kinds of fibres. Fibres dissolving in water are mainly found in vegetables, fruit and leguminous plants. They have a laxative effect. They a positive effect on the cholesterol and glucose percentage in the blood and would therefore be useful for diabetics.

Non-dissolving fibres are mainly found in wholemeal products. They are a means against constipation because they are able to absorb water in the bowels.

Nutritional fibres are only found in unprocessed products. According to our nutritious habits, we get too little of them : wholemeal flour has become white flour, brown rice is white, apples are processed into transparent apple juice. And with the processes, fibres disappear from our daily diet. Besides nutritious fibres don't get destroyed during baking or cooking : they just become softer.

Nutritious fibres are considered to be an important element in the prevention of the typical prosperity diseases such as obesity, heart conditions and cancer of the bowels. A fibre shortage is not the cause of these diseases, but fibres will slow down the development of these diseases. Especially in the industrialized and well-developed countries, these prosperity diseases appear. Exactly in these places, the use of refined products such as white bread, white rice and white sugar is high.

In the study made by the National Council of Nutrition we learn that the average Belgian only gets 21 g of fibres every day while the recommended amount is 30 to 40 g per day.

The message is simple : eat more fibres. Therefore, systematically choose wholemeal bread or rye bread, both of which are rich in fibres. And if you choose for breakfast cereals, at least make an intelligent choice : choose the less sugared ones.

Different kinds of fibre

Traditionally fibre is thought to come from grains This notion has changed greatly in the past few years and as a result the definition of fibre has also changed. The AACC has been instrumental in developing a better definition for fibre. Today it is even possible to make a white bread with the same fibre content as a whole meal bread, just by chosing the right type of fibre and by adding the right amount of it. Today dietary fibre is defined as "the remnants of the edible part of plants, analogous to carbohydrates that are resistant to digestion and absorption in the small intestines". It includes polysaccharides, oligiosaccharides, lignin and similar plant substances. Dietary fibre has a positive effect on laxation (fecal bulking and softening), blood cholesterol levels and/or blood glucose levels.

One dietary fibre used often in the bakery (to make white bread with the same amount of fibres as wholemeal bread) is inulin. There are a number of plants that contain a lot of inulin: bananas, chicory, garlic, onions and yams for instance. What is inulin or inulins? Inulins are a group of naturally occurring polysaccharides produced by many types of plants, and industrially is most often extracted from chicory. The inulins belong to a class of dietary fibers known as fructans. Most plants that synthesize and store inulin do not store other forms of carbohydrate such as starch. Inulins are polymers composed mainly of fructose units, and typically have a terminal glucose (see chemical structure below). The fructose units in inulins are joined by a (2-1) glycosidic bond. In general, plant inulins contain between 20 and several thousand fructose units. Smaller compounds are called fructooligosaccharides, the simplest being 1-kestose, which has 2 fructose units and 1 glucose unit. Basically these are all starches (carbohydrates), just varying in structure. Since inulin is not absorbed from the gastrointestinal tract, it is considered to be a fiber. It is a soluble fiber as opposed to cellulose which is insoluble. It also has a slightly sweet taste and is very low on the glycemic index making it suitable for diabetics.

Commercially, inulin is usually extracted from chicory root although it may also be extracted from Jerusalem artichoke or manufactured by fermenting. The root is chopped and mixed with water to make a wet pulp. The pulp is refined to remove and purify the chicory juice, the water is evaporated and the final product is spray dried to create inulin powder.

The good properties of inulin: inulin is being used as a pre-biotic and showing up in all kinds of foods, especially in bakery products and dairy products. Because it transits to the large intestine almost unchanged, inulin essentially serves as fertilizer for the bacteria in your colon. Certain lactobacillus species of bacteria have been shown to preferentially ferment inulin, especially the Bifidus species. For this reason, it is being promoted as a supplement to feed the good bacteria in our guts. Bifidobacteria digest inulin to produce short chain fatty-acids, such as acetic, propionic, and butyric acids. The first two fatty acids can be used by the liver for energy production, while butyric acid has been shown to have cancer-preventing properties within the intestine. Recent animal research also shows that inulin prevents precancerous changes in the colon.

Studies have shown that inulin alters the gut flora composition in favour of bifidobacteria. More studies need to be done to determine the value of prebiotics. It may be possible to prevent various gastrointestinal complaints through the selectively targeting specific gut bacteria. Other studies indicate that lactobacillus, bifidobacteria and other non-pathogenic bacteria create environments in which pathogenic bacteria are inhibited by modifying pH, producing surfactants that keep pathogens from binding to the lining of the gut and making compounds that are toxic to the undesired bacteria.

Inulin might also have some negative effects in certain individuals. Appart from the fact that it can lead gastrointestinal side effects, such as bloating or gas, inulin might also encourage the growth of Klebsiella. This is a micro-organsim naturally present in the intestines and it is harmless within the colon. But if it comes in other parts of the body it might cause infections.

Also the so called resistant starch is an interesting source of dietary fibre. Carbohydrates, such as sugars and most starch, are rapidly digested and absorbed as glucose into the body through the small intestine and subsequently used for short-term energy needs. Resistant starch, on the other hand, resists digestion and passes through to the large intestine where it acts like dietary fiber. There are 4 different categories of resistant starch but the resistant starch derived from high amylose corn, is the one most used in the bakery. It belongs to the so-called RS2 category. Research of RS2 resistant starches from high amylose corn indicates benefits in intestinal/colonic health as well as metabolic benefits in glycemic management, satiety and hunger. Different types and sources of resistant starch are digested and/or fermented differently and thus must be considered individually

When formulating breads with increased fibre content, I would advise to use a combination of fibres. Each fibre has its own strengths that needs to be taken into account in creating a good "fibre coctail". A good coctail can be created by using 2 parts of insoluble fibre, one part of soluble fibre and one part of resistant starch for instance. Resistant starch will mimic starch like texture. Oat fibre for instance will impart resilience and firmness to the crumb while the soluble fibre will improve softness. When inulin is used as a sole source of fibre, the gluten network does not form very well, however inulin is an excellent source of dietary fibre when used at optimum levels without having negative effects on the structure of the bread.

It is well known that the inclusion of inulin in bread affects dough and bread properties. Processing of the dough is influenced, as well as dough development and bread structure, and measures have to be taken to obtain proper inulin enriched bread. Equally important is the final inulin content of the bread. The effect of bakers yeast on inulin was also investigated, as it is well known that the invertase from this micro organism is able to hydrolyse short chain inulins

The results of rheological studies show that stability of the dough increases with increasing average chain length of the inulin (degree of polymerisation). Water absorption is also affected by the addition of inulin: less water is required for a certain dough consistency following the addition of inulin. This parameter is not affected by the chain length of the carbohydrate or by the protein content of the flour. Dough consistency during kneading is influenced by the chain length of the inulin and by the protein content of the flour. Using less water during dough preparation is not suitable as this will have a negative impact on further dough development and bread structure. On the other hand with more water added to the dough it may become too weak which will hamper processing of the dough. Therefore the addition of an additional ingredient such as CMC to support a proper water distribution during dough development and further processing is beneficial. CMC would absorb the excess water during kneading of the dough and release it during baking, thus leading to proper dough and bread properties.

Inulin also has an effect on the crust. Inulin contains fructan chains that may speed up the caramelization of the crust during baking, giving the baked goods a crunchy brown crust in a shorter amount of time. In this context the baker has too look for the right balance between baking time (which must be sufficiently long) and baking temperature keeping in mind that excessive browning is not desirable.

Nutritional value of bread

The consumer thinks that bread is fattening. NOT TRUE. The butter, the cheese, the jam or the processed meats are much more fattening then a slice of bread. Bread cannot be classified as fattening because it contains little or no fat. Daily bread has an energy value of about 250 kcl/100 g which is many times less then processed meats, cheese etc. Even products such as "Leerdammer Light" or "Milner Light" contain round about 15 % of fat, which is, I admit, much less then the normal cheese but it is still about 10 times as much as in bread.

Nutritional value of bread
bread

% moisture

energy
kcal

proteins
g/100 g

fats
g/ 100g
carbohydrates
g/100 g
white bread
25
290
10,0
0,8
61,0
brown bread
32
270
8,5
1,0
56,0
wholemeal bread
38
250
8,5
2,0
49,0
rye bread
33
270
8,0
1,7
55,5
raisin bread
30
385
8,0
2,0
49,0
milk bread
23
380
10,0
15,5
49,5
croissant
28
570
6,0
40,0
47,0
rusks
9
380
8,0
4,5
75,0


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