THE HYDROLYSIS OF CORN-STARCH BY COMMERCIAL PAiWREATIN

The hydrolysis of potato starch by pancreatin has been the subject of much investigation, particularly by Sherman and his pupils (I), who have studied the action of both malt and pancreatic amylase upon potato starch, especially with reference to optimum concentration of enzyme, substrate, pH value, and concentration of activating salts. The best conditions of hydrolysis were at (2) 40” in the presence of sodium chloride and disodium phosphate which acted as promoters or activators to the diastase. The favorable infiuence of these two salts is explained by the maint’enance of a hydrogen ion concentration most favorable to the activity of the amylase. Potassium and ammonium chlorides are mentioned as exerting the same influence as the sodium chloride, while the combined effect of sodium carbonate and disodium phosphate was found to be the same as when the latter salt was used alone. The hydrolysis of potato starch proceeds more rapidly and completely than the hydrolysis of corn-starch. This fact, which was brought to the attention of t’he authors by Dr. David Klein, led to the present investigation, which deals with the most favorable conditions for the hydrolysis of corn-starch.