Sivell L M, Wenlock R W
Hum Nutr Appl Nutr. 1983 Dec;37(6):459-69.
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.
在伦敦购买了白面包、棕色面包（切片和未切片）、麦芽面包和全麦面包的样本，并对其进行了多种营养素分析。测定了每种面包的混合样本中的可利用碳水化合物、膳食纤维、脂肪酸、核黄素、维生素B6和碘，此外，还对每一条面包分析了水分、脂肪、蛋白质、磷、氯、钠、钾、钙、镁、铁、锌、铜、锰、硫胺素、烟酸以及游离和总叶酸，以便估计每种面包内部的变异性。实际上，在单个面包中测量的所有成分都存在面包间的差异——尤其是水分含量以及钙、铜和叶酸的水平。未切片的面包比切片面包变异性更大，但以干物质为基础表示时，切片面包和未切片面包的营养水平没有显著差异。麦芽面包相对来说是更均匀的产品，但全麦面包非常不均匀，这反映了在零售商店准确识别未包装的全麦面包的困难。在膳食纤维、铁、硫胺素和维生素B6方面，发现与之前公布的所有面包的值存在一些差异。本研究提供的在零售商店采样和分析的经验将被纳入一项针对全英国面包的计划研究的设计中。
