2 BULLETIN" 781, U. S. i1)EPAET]V[E1*TT OF AGRICULTURE. 



butter; kid, hard-palate, and horse fats; oleo oil and oleo stearin; 

 ox-marrow, ox-tail, and turtle fats. Other papers have reported the 

 digestibility of a large number of vegetable fats,^ including olive, 

 cottonseed, peanut, coconut, and sesame oils; cocoa butter; and al- 

 mond, black-walnut. Brazil-nut, butternut, English-walnut, hickory- 

 nut, pecan, corn, soy-bean, sunflower-seed, Japanese mustard-seed, 

 rapeseed, and charlock-seed oils. The oils of such nuts as almond, 

 black and English walnuts, Brazil nuts, and pecan are ordinarily 

 consumed as constituents of the nuts in which they naturally occur, 

 but with these exceptions practically all of the oils studied are com- 

 monly separated from the materials in which they naturally occur 

 before being used for table or culinary purposes. 



POSSIBLE RECOVERY AND USE OF BY-PRODUCT OILS. 



As a result of the enormously increased demand for fats and oils 

 for both technical and edible purposes it has seemed desirable to 

 make a study of the nature and value of fixed oils present in seeds 

 and nuts not hitherto grown or utilized for the production of oil. 

 For some time studies have been carried on by the Department of 

 Agriculture to ascertain the commercial possibilities of recovering 

 the fixed oils contained in many of the pits and seeds occurring as by- 

 products of the fruit canning and drying industries. In 1908 Eabak ^ 

 reported studies on the chemical and physical characteristics and the 

 commercial uses and value of the fixed and volatile oils which may be 

 obtained from the peach, apricot, and prune kernels. He estimates 

 that from 210 to 420 tons of peach-kernel oil (fixed oil) and from 350 

 to 400 tons of apricot oil may be obtained from the by-product peach 

 and apricot kernels produced in California alone. He also estimates 

 that the amount of raisin-seed oil capable of being manufactured 

 from waste raisin seed would be from 348 to 464 tons yearly.^ He 

 states^ that the possible commercial utilization of the waste cherry 

 pits of a normal year's output should yield 134 tons of fixed oil. In 

 a recent paper the same author ^ states that the quantity of oil capa- 

 ble of being extracted from tomato seeds occurring as a by-product of 

 tomatoes used for pulping purposes (catsups, etc.) would be about 

 343 tons annually. 



From these findings it is apparent that the quantity of oil obtain- 

 able from the pits and seeds occurring as by-products is not small. 

 In order to make the recovery of these oils a practical proposition 

 even in those localities where the pits and seeds are to be had in suj35- 



lU, S. DepL Agr. Buls. 505 (1917), 630 (1918), 687 (1918). 

 2u. S. Dept. Agr. Bur. Plant Indus. Bui. 133 (1908), pp. 34. 

 3U. S. Dept. Agr. Bur. Plant Indus. Bui. 276 (1913), p. 30. 

 *U. S. Dept. Agr. Bui. 350 (1916), p. 16. 

 BU. S. Dept, Agr. Bui. 632 (1917), p. 9. 



