The nutritional composition of British bread: London area study

Samples of white and brown bread, both sliced and unsliced, and of wheatgerm breads and wholemeal bread were purchased in London and analysed for a wide range of nutrients. Available carbohydrate, dietary fibre, fatty acids, riboflavin, vitamin B6, and iodine were determined in bulked samples of each type of bread and, in addition, every loaf was analysed for moisture, fat, protein, phosphorus, chloride, sodium, potassium, calcium, magnesium, iron, zinc, copper, manganese, thiamin, nicotinic acid, and free and total folic acid, in order to provide an estimate the variability within each kind of bread. Virtually all the constituents that were measured in the individual loaves showed inter-loaf variation--particularly moisture contents and the levels of calcium, copper and folic acid. Unsliced loaves were more variable than sliced loaves but when expressed on a dry matter basis there were no significant differences in the nutrient levels in sliced and unsliced breads. Wheatgerm breads were relatively more homogenous products but wholemeal loaves were very unhomogenous reflecting the difficulty of accurately identifying unwrapped wholemeal loaves in retail outlets. Some differences from previously published values for all breads were found for dietary fibre, iron, thiamin and vitamin B6. Experience of sampling at retail outlets and analysis provided by this study will be integrated into the design of a planned study of breads throughout Britain.