608 



SCIENCE 



[Vol. LVI, No. 1456 



all other industries in Tvliicli fats are used. The 

 fat should have an iodine absorption number be- 

 low 30. It must contain a minimum of fatty 

 acid esters •which, when hydrolized, will yield 

 fatty acids possessing unusual flavors or odors 

 (e. g., arachidic, theobromic, erucic, ricinoleic, 

 etc. ) . Its ' ' ethyl ester value ' ' should be quite 

 high, preferably, in the purified natural fat, above 

 12. The content of stearin and pulmitin should 

 not be high enough to raise the melting point 

 above 50° C. It should be a fat which is readily 

 purified and should not therefore contain sub- 

 stance such as phytosterol, sitosterol, alkyl 

 amines, etc. Happily enough, eoeoanut oil and 

 palm nut oil which are widely used in the mar- 

 garine industry because of their availability and 

 physical properties come closer to these require- 

 ments than do any of the commercial fats save 

 butter fat. Inasmuch as the margarine industry 

 used eoeoanut oil it was but natural that the 

 compound milk industry should choose it. From 

 the standpoint of condensation in the vacuum pan 

 in the presence of the milk, a good grade of 

 eoeoanut oil works more admirably than does 

 butter fat itself. The same may be said of palm 

 nut oil. The high iodine number of some butter 

 fats, 28-42, renders it subject to slight rancidifi- 

 cation (hydrolysis) in the vacuum pan and sub- 

 sequent sterilization. Partially hydrogenated 

 cotton oil may be used providing its iodine num- 

 ber is kept about 30, so that its melting point 

 will not interfere with the pan process. 



The analytical detection of rancidity: Eobert 

 H. Kerk. The analytical tests used for the recog- 

 nition of rancidity, the chemical and physical 

 differences between rancid and sweet fats, and 

 \n\\ give some consideration to the mechanism of 

 rancidity and the changes involved in its develop- 

 ment. 



Eancidity and a method for its detection: H. C. 

 Bashioum and R. J. Noble. Eancidity of two 

 types, "A" and "B" — "A du-e to volatile fatty 

 acids, " B " due to volatile fatty acids and alde- 

 hydes. Eancidity "B" detected and compara- 

 tively estimated by means of SchifE's Reagent 

 (pararosaniline acetate dissolved in dilute sul- 

 furous acid solution). A 0.5-1.0 per cent, solu- 

 tion of the oil in kerosene or preferably benzene 

 is shaken vfith an equal volume of the reagent in 

 a separatory funnel, continuously or inter- 

 mittently for 30 minutes. If the oil be rancid, a 

 violet to blue coloration will appear immediately 

 or within a few minutes in the benzene or kero- 

 sene layer. The color developed is proportional, 

 within limits, to the degree of rancidity. The 

 test is very delicate and especially suitable for 



the detection of "B" in cereal products contain- 

 ing small amounts of oil. 



The oil, fat and tuax laboratory, Bureau of 

 Chemistry, Department of Agriculture, and its 

 relation to the vegetable oil and fat industry: 

 George S. Jamieson and Walter F. Baughman. 

 An account of the vegetable oil and fat investi- 

 gations conducted by this laboratory, discussed 

 under three heads: Olive oil and its substitutes, 

 supply of fats and oils during the war and funda- 

 mental investigations. It is almost impossible to 

 get adulterated olive oil past the barriers at our 

 ports. The small amount of adulterated oil on 

 the market is sophisticated in this country by 

 small firms. During the war our imports of fats 

 and oils exceeded our exports. The first complete 

 survey of the fat and oil industry was made. It 

 was not possible to increase production of cot- 

 tonseed oil, but production and importation of 

 peanut and soya bean oils were greatly increased. 

 Many new possible sources of oil were investi- 

 gated. The chemical composition of some of the 

 vegetable oils have been determined. A repre- 

 sentative number of authentic samples of cotton- 

 seed and peanut oils have been analyzed to 

 establish the limits of variations in the chemical 

 and physical characteristics of these two oils. 

 A new method has been developed for deter- 

 mining the amount of neutral oil in crude oils. 

 Work is in progress on the isolation and identifi- 

 cation of all constituents of cottonseed oil and 

 their effect on refining. 



Colorimetry as applied to the vegetable oil 

 industry: David Wesson. Cottonseed oil has 

 always been sold on color and various means have 

 been devised from time to time for reading and 

 recording color. Modern conditions have called 

 for more accurate instruments than those used in 

 the past, using Levibond Tintometer glasses. The 

 Eastman Kodak colorimeter furnishes an ideal 

 instrument for measuring and recording the color 

 of samples where colorimetric measurements only 

 are desired. Where it is necessary to analyze a 

 color as in research work, the new Keuffel and 

 Esser color analyzer is to be preferred. 



A brief note on the examwmtion of the fat from 

 Theobroma grandiflora: W. C. Tabor. 



A rapid quantitative method for the determina- 

 tion of arachidic-lignoceric acid mixture in peanut 

 oil: Akthtjr W. Thomas and Chai-Lau Yu. 



The chemical composition of sunflower seed oil: 

 George S. Jamieson and Walter F. Batjghman. 

 Sunflower seed oil is used in various foreign coun- 

 tries as a food oil and in making butter substi- 

 tutes, soaps, varnishes and enamels. Several 

 million pounds of the seed are produced annually 



