Optimal conditions for phytate degradation, estimation of phytase activity, and localization of phytate in barley (cv. Blenheim).
Using a multivariate experimental design, optimal conditions for phytate degradation were found to be pH 4.8 and 57 degrees C in barley flour (cv. Blenheim) and pH 5.2 and 47 degrees C in a crude extracted phytase from barley. Three methods for measuring phytase activity in raw and hydrothermally processed barley were compared. Incubation at pH 5 and 55 degrees C for 60 min did not give significantly different results (p > 0.05), whereas incubation at pH 5 and 50 degrees C for 10, 20, 30, and 60 min gave significantly different results (p < 0.001) between methods. The change in microstructure of phytate globoids during hydrothermal processing showed that the degradation was highest in the scutellum cells and less in the aleurone layer.
Bergman
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Department of Food Science, Chalmers University of Technology, P.O. Box 5401, SE-402 29 Göteborg, Sweden. eva-lotta.bergman@fsc.chalmers.se
Autio
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Sandberg
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D010832:6-Phytase / Q000737:chemistry*; D005433:Flour / Q000032:analysis; D001467:Hordeum / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010833:Phytic Acid / Q000737:chemistry*
D010833:Phytic Acid; D010832:6-Phytase