CARBOHYDRATES 



39 



-CH 2 



Maltose. 



EXPERIMENTS ON MALTOSE 



1-6. Repeat Solubility, Fehling's, Nylander's, Phenylhydrazine, Barfoed's 

 and Fermentation tests as given under Glucose, pages 21-31. 



ISO-MALTOSE, C 12 H 22 On 



Iso-maltose, an isomeric form of maltose, is formed along with mal- 

 tose, by the action of diastase upon starch paste, and also by the action 

 of hydrochloric acid upon glucose. It also occurs with maltose as one 

 of the products of salivary digestion. It is dextro-rotatory and with 

 phenylhydrazine gives an osazone which is characteristic Iso-maltose 

 is very soluble and reduces the oxides of bismuth and copper in alkaline 

 solution. Pure iso-maltose is probably only slightly fermentable. 



LACTOSE, Ci 2 H 22 On 



Lactose or milk sugar occurs ordinarily only in milk, but has often 

 been found in the urine of women during pregnancy and lactation. It 

 may also occur in the urine of normal persons after the ingestion of 

 unusually large amounts of lactose in the food. It has a strong reducing 

 power, is dextro-rotatory and forms an osazone with phenylhydrazine. 

 Upon hydrolysis lactose yields one molecule of glucose and one molecule 

 of galactose. 



In the souring of milk the Bacterium lactis acidi or Streptococcus 

 lacticus and certain other micro-organisms bring about lactic acid 

 fermentation by transforming the lactose of the milk into lactic acid , 



H OH 



I I 

 H C C COOH, 



H H 



