CHEMICAL PUOPliUTlES OF FATS AND OILS 293 



ported its synthesis from two molecules of 1-piperoiiyl-l-bromoethane. 

 This latest work confirms the structure assigned to it by Hawortli et al.'"^'^ 

 The addition of NDGA to fats up to a maximum concentration of 0.01% 

 was permitted by the War Food Administration under the Meat Inspec- 

 tion Division (U. S. Department of Agriculture), Memorandum No. 25, 

 issued December, 1943. 



(e) Gum Guaiac. The active principle in gum guaiac is presumably 

 guaiaretic acid. The gum is a secretion of the tropical tree, Guajacum 

 officinale (lignumvitae). Newton and Grettie*^" have described its use for 

 the protection of lard, and the federal government has approved the addi- 

 tion of this product to lard up to a maximum of 0.1%. Grettie*"^^ has dem- 

 onstrated its effectiveness as an antioxidant. Higgins and Black*^^ have 

 reported that the addition of gum guaiac in amounts of 0.1% to prime 

 steam lard delayed rancidit.y from 6 to 24 hours, as determined by the 

 active oxygen method, from 7 to 23 days, as determined by the oven test 

 at 60°C., and from 5 to 35 days, according to the oven test on crackers at 

 60°C. Gum guaiac behaves like the phenolic antioxidants, but it is less 

 eiTective than most of them. It resembles them in being more effective on 

 animal than on vegetable fats.^^^ The complete innocuousness of gum 

 guaiac, when fed in amounts far in excess of any possible level of consump- 

 tion in fats, has been demonstrated by Johnson, Carlson, Kleitman, and 

 Bergstrom.^^^'' 



(/) Propyl Gallate and Gallic Acid. Boehm and Williams^^*-^'^'' first de- 

 scribed the use of propyl gallate as a potent phenolic antioxidant. It has a 

 lower toxicity than pyrogallol. It dissolves sparingly in fats, although 

 Lundberg*^^ states that 1.6 g. will dissolve in 100 g. of soybean oil. It has a 

 lower solubility in lard,"- but it is extremely soluble in ethanol.'*^* Propyl 

 gallate is approved by the Meat Inspection Division of the U. S. Depart- 

 ment of Agriculture"^ as a stabilizer for fats in amounts not exceeding 

 0.01%. Higgins and Black"^ have reported that propyl gallate is effective 

 for preserving lard but not for crackers. 



Lea^'-'- has demonstrated that lower aliphatic esters of gallic acid other 

 than the propyl ester are likewise effective antioxidants. The use of some 



6'6 R. C. Newton and D. P. Grettie (to Swift & Co.), U. S. Patent No. 1,903,126 (March 

 28, 1933); French Patent No. 741,417 (Aug. 20, 1932); Chcm. Abst., 27, 2833, 3354 

 (1932). 



5" D. P. Grettie, Oil & Soap, 10, 126-127 (1933). 



5>8 J. W. Higgins and H. C. Black, Oil & Soap, 21, 277-279 (1944). 



*!»" V. Johnson, A. J. Carlson, N. Kleitman, and P. Bergstrom, Food Research, S, 

 555-574 (1938). 



"^ E. Boehm and R. Williams, Quart. J. Pharm. Pharmacol., 16, 232-243 (1943). 



520 E. Boehm and R. Williams, Pharm. J., 151, 53, 163-164 (1943). 



"1 U. S. Dept. Agr., Meat Inspection Div., Memo. No. 104, Cited by W. O. Lund- 

 berg, Publication No. 20, Hormel Institute, University of Minnesota, 1947, p. 25. 



"2 C. H. Lea, J. Soc. Chem. Ind., 63, 107-112 (1944). 



