Nutritional properties of bread

The composition of the dry matter of wheat varies widely depending on soil, climate and genetic variations between wheat types. Wheat in New Zealand has a protein content that ranges on average from 8% to 13%. It has a high carbohydrate content of about 83% of the weight of a kernel.

Other components of the wheat grain include bran and germ. Bran, the outer coating or “shell”, is rich in B vitamins and minerals.

The wheat germ or embryo is a rich source of B vitamins, oil, vitamin E and fat. It needs to be discarded during milling because the fat is liable to become rancid during storage. It is still very valuable and is used in many products.

Minerals contained in wheat include calcium, phosphorous, potassium, iron, magnesium and sodium.

Vitamins such as thiamine (B1), riboflavin (B2), pantothenic acid, inosotol, P-aminobenzoic acid, folic acid and vitamin B6 are also distributed throughout the wheat grain.
All the nutrients contained in wheat make bread an essential part of the diet. Bread is one of the cheapest, high quality nutritious foods in New Zealand and not only provides many essential nutrients but is also low in fat, cholesterol and sugar.

While current thinking is promoting whole grain breads and cereals as the better choice for maintaining health, white bread has properties which make it an equally valid choice as part of a balanced diet.
American vs. New Zealand bread

Often the facts about white bread referred to on websites or in the media are misleading as they refer to white bread made in the USA or UK rather than in New Zealand.

In New Zealand, the milling extraction rate of wheat grain for white bread is much higher than in the USA. The New Zealand extraction rate is 78% compared with a rate of less than 75% in the USA. A higher milling extraction rate means that higher levels of nutrients (B vitamins, protein and carbohydrate) are retained in New Zealand bread. Therefore it is not necessary to add synthetic vitamins and minerals into New Zealand bread as occurs in the USA and UK.

Americans prefer their breads to be sweetened, so sugar is added to the bread. In New Zealand sugar is added purely to be used in the fermentation process and enhance add to flavour. Only traces of sugars, around 1-3 g per 100 g of white bread, are left in the final product.

In New Zealand there are also tight restrictions on what ingredients can be added to bread. In the USA, bleached flour is used for making bread. Bleached flour has been treated with chlorine to speed up the natural lightening and maturing of flour. Bleached flour is not permitted for use in New Zealand and there are fewer chemicals in New Zealand bread. Most bread packaging here states that no artificial colours or flavours have been added.
Facts about white bread in New Zealand

White bread gets its goodness from the flour that is used to make it. The white flour used in white bread is produced from the endosperm of the grain, which is a rich source of carbohydrate and protein. White bread has approximately the same carbohydrate and protein content as wholemeal bread, and contains some dietary fibre and a good percentage of the nutrients of wholegrain bread.

Some consumers perceive white bread to be fattening. Energy in bread comes from the complex carbohydrates present, not from fat or sugar as with most processed foods. The energy content of white bread is approximately 1040 kJ per 100 g, or 380 kJ in each 37 g slice. This is actually a lot lower than other snack foods, such as potato chips (approximately 2180 kJ per 100g or 981 kJ per 45 g bag) or snack bars (1600 kJ per 100 g).

The quantity of fat in white bread is small at around 2.5 g per 100 g, while the saturated fat content is usually less than 1 gram per 100 g. Most bread made in New Zealand contains vegetable oil in small amounts to improve the texture and the keeping quality of the bread. The most commonly used vegetable oil is canola. A monounsaturated oil or ‘good oil’, canola is known to lower total fat and LDL cholesterol in the blood. Bread contains no cholesterol as no animal fats are added during its manufacture.

Be aware of what you are spreading on your bread as this can dramatically increase the amount of fat and energy of the meal or snack. All yellow spreads (butter, margarine) are high in fat, with some margarines containing 12-14 g fat in every tablespoon. It is not the bread that is fattening but the spread. Try using jam and honey on bread without butter or margarine or choose alternatives such as light cream cheese (3 g fat per tablespoon) or avocado (4 g fat per tablespoon) for sandwiches.

White bread may not contain the same high levels of fibre that wholemeal or multigrain breads contain, but it is still a valuable source of fibre, especially if the total amount of white bread consumed in the diet is considered. 100 g of white bread contains approximately 2.5 g fibre, whereas wholemeal and mixed grain products contain between 4 g and 7 g fibre per 100g bread. However, there are now high-fibre white breads available on the market such as Natures Fresh Hi-Fibre White and TipTop UP Iron & Double the Fibre. These breads contain added vegetable or cereal fibre which doubles the amount of fibre present in the white bread to approximately 4.8 g fibre per 100 g.

White bread is also an important source of protein in the New Zealand diet. 100 g of white bread contains 8 g of protein – that’s 8%. For comparison, milk contains 3% protein and eggs contain 12% protein. However, because bread is a cereal source of protein it is important to combine bread with animal proteins such as cheese or milk to make sure that you are consuming a good source of complete protein and that you are receiving all the amino acids required to build protein in the body.

White bread is also an important source of vitamins and minerals. The B vitamins present in white bread are naturally occurring due to their presence in the wheat grain. White bread has 50% of Vitamin B1 (Thiamine), the same level of Vitamin B2 (Riboflavin) and 30% of the level of Vitamin B3 (Niacin) that is present in wholemeal bread. Although these amounts are lower than wholemeal bread, white bread is still a significant source of these vitamins. All breads supply calcium, but it is more available in white bread. In wholemeal or grain breads, phytates are present which bind to the calcium and prevent or slow its absorption in the body.

The Glycaemic Index (GI) ranks the carbohydrate present in foods, based on its immediate effect on blood glucose levels. In high GI foods, the carbohydrate present is broken down quickly during digestion. This corresponds to high blood glucose levels, although these are short lived. White bread is a high GI food, but this does not make white bread a bad food choice. What it does mean is that after eating white bread, there will be a more instant burst of energy as glucose rapidly moves into the blood. Eating high GI foods can be useful after exercise to replace the energy used during the activity.

Six to 11 servings of cereal products are recommended per day, depending on your age and activity level. Substituting fatty and sugary foods with starchy foods such as white bread can help reduce over eating and obesity. Therefore as white bread provides an array of nutrients, such as B vitamin, protein and carbohydrate, it is an important food to include in a balanced diet.

The B vitamins, niacin, riboflavin and thiamin, are essential nutrients that cannot be made by our bodies in sufficient amounts for our needs. They need to be supplied by our diet and must be consumed regularly as they are not stored in our bodies.

The main function of thiamin is to break down carbohydrates into sugars to produce energy. Riboflavin is necessary for the production of energy in the body and niacin is essential for making use of the energy produced in all cells.

Calcium is an essential mineral for bone production and maintenance of healthy bones and teeth. New Zealander’s are actively encouraged to maintain a reasonable level of calcium intake throughout life. Iron is also an essential mineral required in our bodies. It assists with the transport of oxygen to the cells where it is used. It is part of a pigment called haemoglobin in the red blood cells. Potassium is contained inside the cells of our bodies. It enables cells to have the correct fluid mixture they need to work properly.

Dietary fibre is a mixture of many different components that give a rigid structure to plant cell walls. It helps food pass through our digestion system more easily and has been shown to reduce the effects of some common ailments such as constipation and other similar problems.

Nutrient content is affected by extraction rate (the amount of flour removed from the grain). White flour (usually extracted so that 78% of the grain remains in the flour) contains a lower proportion of some nutrients than 100% extraction rate wholemeal flour. The difference between wholemeal flour and white flour is that the bran and germ layers are removed during white flour milling. Wheat germ is a very good source of B vitamins and extremely rich in iron, zinc, manganese and copper. It is also the richest plant source of vitamin E.

Pure wheat bran is the richest known source of dietary fibre and contains minerals (such as manganese and iron) and vitamins (niacin, vitamin B6).

When you compare white flour and wholemeal flour in the table you will see that wholemeal flour contains on average 3.6 times the quantity of fibre contained in white flour. However, white flour is still a good general source of dietary fibre, and is also an excellent source of other essential nutrients, including carbohydrates, amino acids, magnesium, manganese, phosphorus, potassium, sodium, sulphur, zinc, selenium and lipids.

All flour is nutritions so no matter which type you use it will contribute towards a healthy diet.