Phospholipase, cereal

Only one acyl residue is cleaved by hydrolysis (cf. 3.7.1.2.1) with phospholipase A. This yields the corresponding lyso-compounds from lecithin or phosphatidyl ethanolamine. Some of these lyso-derivatives occur in nature, e. g., in cereals. Phosphatidyl glycerol is invariably found in green plants, particularly in chloroplasts ... 

It should be taken into account in lipid extraction that the phospholipase D activities are relatively high in ripe cereals and this enzyme transfers the phosphatidyl residue of phospholipids to alcohols, which are used to extract lipids (cf. 3.7.1.2.1). The enzyme is inactivated during extraction with boiling water-saturated butanol. A phospholipase that hydrolyzes both acyl residues in the lecithin molecule ( phospholipase B ) has been found in germinating cereal. It influences the foam stability in beer (cf. 20.1.7.9). 

Acker, L. Phospholipases of cereals. In Advances in cereal science and technology (Ed, Pomeranz, Y,), Vol. VII, p. 85, American Association of Cereal Chemists St. Paul. Minn. 1985 Ali, M. R., D Appolonia, B.L. EinfluB von Roggen-pentosanen auf die Teig- und Broteigenschaften. Ge-treide Mehl Brot 33, 334 (1979)... 

Lysophosphatidyl cholines (LPC), which occur in cereal as amylose inclusion compounds (starch lipids cf. 15.2.5), reduce the foam stability. The terrqterature management during the mashing process regulates the LPC concentration because it determines the activity ratio of a-amylase, which contributes to the release of LPC from amylose, to phospholipase B, which catalyzes the... 

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