Why is “high heat” nonfat dry milk the type to be used in yeast raised bakery foods?
The decreased volume and slack dough obtained with low heat milk is similar to the action obtained when adding excessive amounts of the reducing agent cysteine. It is thought that the dough softening action is caused by the sulfhydryl groups of cysteine and that during heat treatment, these groups are either oxidized or otherwise modified. Additional work has shown that the dough softening ingredient is present in the milk serum protein which makes up about 7.5% of the nonfat dry milk. The denaturization of these serum proteins is believed the main reaction involved in eliminating the undesirable effect. High heat treatment corrects these conditions.
