Distribution of phytase activity, total phosphorus and phytate phosphorus in legume seeds, cereals and cereal by-products as influenced by harvest year and cultivar

Effect of germination on the phytase activity, phytate and total phosphorus contents of rice (Oryza sativa), maize (Zea mays), millet (Panicum miliaceum), sorghum (Sorghum bicolor) and wheat (Triticum aestivum)

“…One factor responsible for the large variations in literature values is the differences in analytical procedures used for the determination of phytase activity. As previously shown by Greiner and Egli (2003), phytase activities in cereals based on extraction methods are considerably lower than those obtained by means of direct incubation methods (Steiner et al 2007). According to Greiner and Egli (2003) the incomplete extraction of plant phytases might be attributed to proteolytic degradation and a partial association of the enzymes with membrane structures.…”

“…With the exception of maize and sorghum significant differences (P<0.05) were observed in the phytase activities (0.21-0.67 U g -1) of the cereal grains screened. Steiner et al (2007) reported a range of 0.4-6.0 U g -1 for oats, barley, triticale, rye and wheat. They reported 2.8 U g -1 for wheat, which is higher than that presented in this study (0.67 U g -1 ), while Cossa et al (2000) reported 0.520-1.4 U g -1 for wheat, which is in agreement with the present study.…”

“…According to Greiner and Egli (2003) the incomplete extraction of plant phytases might be attributed to proteolytic degradation and a partial association of the enzymes with membrane structures. Differences in the composition of the cell walls, interaction of phytases with morphological grain fractions and differences in the location of the enzymes within the grains are considered to be additional factors responsible for the incomplete and different extraction rates of plant phytases (Steiner et al 2007). Generally, high native phytase activities are present in cereals and cereal by-products, whereas lower activities have been reported for legume seeds (Steiner et al 2007).…”

“…The phytases used for this purpose are usually of microbial origin and the technology involved in the extraction, purification and thermo-stabilization of the enzymes is still beyond the reach of developing countries especially in Africa. High native phytase activities are present in cereals and cereal by-products (Steiner et al 2007). It appears that phytase activity usually increases on germination (Sung et al 2005) and germination has been used to induce phytase activity in cereals (Senna et al 2006).…”

Phytic acid concentration in selected raw materials and analysis of its hydrolysis rate with the use of microbial phytases during the mashing process

“…Phytic acid, also known as inositol hexakisphosphate (IP6), is regarded as primary phosphorus storage compound accounting for up to 80% of the total phosphorus in plant seeds (1,2). Phytates (phytic acid salts) are accumulated mainly in the seed aleurone layer and the embryo (3).…”