in. INDUSTRIAL PREPARATION 341 



the filter cake is washed thoroughly with water to remove retained steep- 

 water. The crude product, essentially a mixed calcium-magnesium salt of 

 phytic acid which contains the impurities mentioned, has often been refer- 

 red to in the literature as "phytin" or as "calcium phytate." This product 

 may be dried by conventional procedures or may be used directly for 

 hydrolysis to inositol. 



Various procedures also may be employed to improve the quality of 

 crude phytate obtained from steepwater. Use of so-called "light steep- 

 water" for precipitation of the phytate, purification of the crude phytate 

 by treatment with alkali, and other modifications may help to reduce the 

 nitrogen content of the crude phytate and give a better raw material for 

 hydrolysis to inositol.^' "^ 



D. HYDROLYSIS OF PHYTATE TO INOSITOL 



Inositol has been obtained from steepwater phytate by hydrolysis under 

 a variety of conditions.**"'" Temperature, pressure, pH, and time of hy- 

 drolysis are variables which have been considered. Temperatures employed 

 have ranged from approximately 100° to 200°, pressures from atmospheric 

 to mild autoclaving conditions, and the medium for hydrolysis from a 25 % 

 calcium hydroxide slurry to a 60% sulfuric acid solution. The time re- 

 quired for completion of hydrolysis has usually been several hours. 



According to Bartow and Walker^ inositol can be obtained conveniently 

 by heating phytate under pressure with either water or acid. The quality 

 of the phytate used and the nature of the impurities present during hy- 

 drolysis appear to have as much influence on the yield of inositol as does 

 any other factor, including the nature of the conditions chosen for hy- 

 drolysis. The calculated yield of inositol based on pure diy calcium phytate 

 is 20.27 %, but the yields of inositol reported to be obtained from steepwater 

 phytate have generally been in the range of 7 to 12 %. 



E. ISOLATION OF INOSITOL FROM HYDROLYZATE 



Hydrolysis of phytate produces 6 moles of inorganic phosphate for each 

 mole of inositol. The inorganic phosphate produced by hydrolysis of phytate 

 may be removed by filtration if the hydrolyzate is first adjusted to a pH 

 that is slightly alkaline. 



The phosphate filter cake is washed with hot water to remove dissolved 

 and adsorbed inositol, and the wash filtrate is combined with the original 

 filtrate. The combined filtrate, a crude aqueous solution of inositol, may be 



« F. A. Hoglan and E. Bartow, J. Am. Chem. Soc. 62, 2397 (1940). 

 ' Corn Products Refining Co., Brit. Pat. 601,273 (May 3, 1948). 



8 E. Bartow and W. W. Walker, Ind. Emj. Chem. 30, 300 (1938). 



9 E. Bartow and W. W. Walker, U. S. Pat. 2,112,553 (March 29, 1938). 



'" E. Elkin and C. M. Meadows, U. S. Pat. 2,414,365 (January 14, 1947). 



