486 MANUAL OF MILK PRODUCTS 



FOOD VALUE OF FERMENTED MILK 



The high food value of milk is too generally recognized to need 

 discussion here ; fermented milks also have a high food value, 

 except that in some cases the fat is partially or entirely re- 

 moved. Otherwise the food value of the fermented milk differs 

 little from that of the fresh milk from which it is made. Any 

 increased digestibility of the fermented milk is due not so much 

 to change in the chemical nature as to the fact that the casein 

 is furnished in a precipitated and finely divided condition. In 

 none of the fermented milks is there any material cleavage of 

 the casein resembling the digestion in the stomach. The fat 

 is practically unchanged, and a part only of the sugar is con- 

 verted into acid, alcohol, or gas. In certain gastric troubles 

 in which it is difficult to find any food that can be retained 

 by the patient, fermented milks are frequently used with good 

 results. Kefir and kumiss especially are used under such cir- 

 cumstances, as the stimulating action of the carbon dioxid 

 which they contain is believed to aid in their digestion. To the 

 physician the value of a highly nutritious food which can be 

 digested when other foods are rejected is obvious. 



There are many questions that should be very carefully 

 considered before a fermented milk is introduced as an im- 

 portant part of the diet. As Herter has pointed out in the 

 admirable paper already cited, the addition of fermented 

 milk to the diet may change very materially the ratio of pro- 

 tein to other classes of food. If the milk is taken in place of 

 other food, the daily protein ration may be so reduced that 

 intestinal putrefaction, which is dependent on the protein 

 part of the food, is diminished. On the other hand, if milk 

 is added to the usual food, the protein ratio may be increased 

 rather than diminished. In many cases the condition of the 

 mucous membranes will not permit the presence of organic 

 acid, and soured milk cannot be retained. It is also possible 



