Abstract
[purpose] An inorganic phosphorus is often used for a processed food as food additives, and these are known to have better digestion than organic phosphorus. For a kidney disease patient, the excessive intake of phosphorus tend to causes the hyperphosphatemia so that they have to note the food additives, but the phosphorus-containing food additives are hard to understand from the indication written on the packages. We investigated the quantity of the total, water-soluble (high inorganic phosphorus content), and insoluble (high organic phosphorus content) phosphorus in some breads. [method] Six commercial bread and one bread for the kidney disease patitents are homogenized with water, centrifuged and separated to a water-soluble fraction and a water-insoluble fraction. These fractions and no treatment breads are baked and ashed. The determination of phosphorus content is based on the vanadomolybdate method. The quantity of phosphorus in the breads are compared whether food additives (yeast food, emulsifier) are included or not. [results] The quantity of total phosphorus in the bread for the kidney disease was approximately 54% of total phosphorus and 31% of water-soluble phosphorus respectively. Compared with the amount of phosphorus in the 6 commercial bread, the significant difference was seen in the water-soluble phosphorus, but not seen in the total phosphorus. When the quantity of estimated absorption ratio are 90% in water-soluble phosphate, and 50% in insoluble phosphate, the amount of the phosphate of the bread including food additives were significantly high. [consideration] Although the quantity of phosphorus did not habe the shifnificant difference in commercial bread, it was suggested that estimated absorption ratio would be higher in the bread containing yeast food and emulsifier. The kidney disease patient should be careful about the bread including these food additives. However, packages of foods have no mention that phosphorus is included in the food additives. We expect a mention to understand what phosphorus is included in the food additives.
