Phytate Content of Soft Wheat Brans as Related to Kernel Size, Cultivar, Location, and Milling and Flour Quality Parameters

Cereal Chem. 69(5):577-581 The phytate content of wheat bran is of interest because bran, an cultivars. Phytate content of the brans from 15 soft wheat cultivars grown important dietary fiber source, contains significant amounts of phytate, at three different locations during the same crop year was influenced which has been reported to impair mineral retention under certain dietary strongly by environmental factors. For these cultivars, the phytate content circumstances. The purposes of this study were to examine the phytate of the bran was significantly (P < 0.01) correlated with the milling paramcontent of brans from soft wheat cultivars as influenced by kernel size eters percent flour extraction, endosperm separation index, and friability and growing location and to determine whether any relationships existed (r = 0.53, -0.41, and 0.47, respectively). These correlations suggest that between phytate content and flour and milling quality parameters. The endosperm is more easily separated from bran and reduced to flour when influence of kernel size upon bran phytate content was determined in it is from soft wheats in which the bran phytate content is greater. The six soft wheat cultivars. The phytate content was significantly greater rankings of bran phytate content and milling and flour quality parameters (12-24%) in bran obtained from the larger kernels in three of the six were highly variable across cultivars and growing locations. Phytic acid (myo-inositol 1,2,3,5/4,6-hexakis[dihydrogenphosphate]) is a compound found in most mature cereal seeds that provides from 40% to more than 80% of the total phosphorus in the seed (O'Dell et al 1972, Lolas et al 1976). It frequently occurs as phytin, a mineral storage material that is used to support seedling growth. In many cereals phytin is found in electrondense particles called globoid crystals that consist mainly of a mixed magnesium and potassium salt of phytic acid (Lott and Ockenden 1986). A major part of the phytate in wheat grains is found in the aleurone layer (O'Dell et al 1972, Wada and Maeda 1980). During the milling process, most of these aleurone cells remain with particles of pericarp; hence phytate becomes concentrated in the bran fractions. Therefore, whole wheat may contain about 0.3% phytate and the bran may contain 5% (O'Dell et al 1972).