The drying of wheat. IV. Phosphatase activity as an index of heat damage in cereals

The baking quality, germination vitality and phosphatase activity of a wheat were examined after heat treatment at moisture contents ranging from 5.5 to 35%. Curves relating the percentage of phosphatase inactivation to temperature of treatment are presented. The correlation between phosphatase inactivation and damage to either vitality or baking quality varies with moisture content and is less than that between vitality and baking quality in the important region above 15% moisture. The detection and uset of an ezyme system of greater heat lability than phosphatase is desirable for the unequivocal diagnosis of mild damage to either vitality or baking quality of wheat.