FACTORS INFLUENCING DIASTASE FORMATION 



231 



The water content of the air-dry grains increased only slightly 

 when suspended above a saturated solution of CaCl 2 at 5, 10, 

 15, 20, and 25°C. respectively. The total increase of water con- 

 tent in the range of temperatures used is 1.07%. Above a solu- 

 tion of half that density, an increase in temperature of 5°C. is 

 sufficient to cause an increase in water content, (1.07%) equiva- 

 lent to that obtained throughout the whole range of tempera- 

 ture (5°C. to 25°C.) above a saturated solution. In the range 

 of temperatures used (5°C. to 25°C.) an increase of 4% in the 

 water content was observed. Above the other concentrations of 

 the salt solution an increase of 5°C. produces an increase of 



TABLE 5 



Comparison of the water content of grains immersed in a saturated solution of LiCl 



at 30°C. with diastase activity 



from 1 to 1.5% in the amount of water imbibed. When distilled 

 water is used, the effect of the temperature is about the same as 

 in the more dilute salt solutions; an increase of 5°C. producing 

 an increase of from 1 to 1.5% in the water absorbed. 



In column 5 of table 5 are given the amounts imbibed, in per 

 cent, by barley grains immersed in a saturated solution of LiCl 

 at 30°C. In this case it is the time factor and the approach to 

 imbibitional equilibrium that produces the differences in water 

 content. At the end of two hours the grains absorb 14.85% of 

 water, that is, have a total water content of 23.61% — water con- 

 tent of air-dry grains, 8.76% plus 14.85% increase. The quan- 

 tity of water taken up was unexpectedly large. The results ob- 

 tained by Shull in his experiments with Xanthium show a much 



