By the action of a peptonizing powder which is composed of a digestive agent known as the extractum pancreatis and bicarbonate of soda, which is added to the plain or diluted milk. This is sold in tubes or in tablets, and it is the active ingredient of the peptogenic milk powder.
Describe the process.
The plain or modified milk is placed in a clean glass jar or bottle, and the peptonizing powder, which is first rubbed up with a tablespoonful of the milk, is added and the bottle shaken. The bottle is then placed in a large pitcher or basin containing water kept at the temperature of about 110° F., or as warm as the hand can bear comfortably, and left for ten to twenty minutes if the milk is to be partially peptonized; for two hours if it is to be completely peptonized.
What taste has partially peptonized milk?
None, if peptonizing is continued for only ten minutes, but at the end of twenty minutes it begins to be bitter, when the process of digestion has gone further.
How is the bitter taste avoided in partially peptonized milk?
At the end of ten or fifteen minutes the milk may be placed in a saucepan and quickly raised to boiling point; this kills the ferment, so that the milk will not become bitter when warmed a second time. Or, the milk may be rapidly cooled by placing the bottles first in cool and then in ice water; in this way the ferment is not destroyed, and the milk may become bitter when warmed for feeding.
Should the whole day's supply be peptonized at once, or each bottle separately just before the feeding?
Either plan may be followed. If the former, it is better to raise the milk to boiling point after peptonizing; if the latter, it should not be peptonized more than ten minutes, for it will continue to peptonize while it is being taken by the child.
Is not the bitter taste of completely peptonized milk a great obstacle to its use?