Effects of differences in manufacturing methods and raw materials on the mineral composition of bran-derived phytin

抄録

Phytic acid is usually deposited in dormant seeds bound to minerals in the form of phytin. Bran is a byproduct of grain processing and used as a raw material for phytin production. In this study, commercially available rice bran and wheat bran were used as raw materials, and phytin was extracted and prepared by four typical production methods: alkali addition, calcium salt addition, magnesium salt addition, and ethanol precipitation. In addition to phosphorus, the raw bran contained magnesium, calcium, manganese, zinc, and iron, and these minerals were also recovered in all phytin products. The phytin products produced by alkali addition showed a mineral composition that was almost identical to the proportions found in the bran. The addition of alkali metal salts increased the corresponding metal content in the phytin products, suggesting that magnesium and calcium may be antagonistic in their binding to phytic acid. Ethanol precipitation resulted in lower calcium and magnesium recoveries and a relatively higher iron content. Among the phytate products obtained, those with a high iron ratio were amber in color, while those with a high manganese ratio were pink. The mineral composition in phytin is affected and complicated by the type of raw material and method of production, and the mineral composition in phytin and phytic acid must be noted when interpreting the results of animal studies on phytin and phytic acid.