6 



BULLETIN 399^ U. S. DEPARTMENT OF AGEICULTURE. 



attached to the distilling apparatus. When the gauge indicates 

 sufficient diminution in the pressure, steam is admitted into the 

 jacket of the retort. The thin mixture of water and peel begins 

 to boil almost immediately, and the water vapors passing into the 

 condenser carry the oil with them. Here the vapors are condensed 

 and the distillate is collected in the receiver. The oil being lighter 

 than water floats on the surface and can easily be separated. The 

 peel is exhausted in about 30 minutes. Steam can also be admitted 

 directly into the retort and the oil extracted under diminished pres- 

 sure by direct steam. The oil obtained by vacuum distillation was 

 light lemon yellow in color and possessed a pleasing orange odor and 



the characteristic aro- 

 matic orange taste. 



The oil obtained by 

 direct steam distilla- 

 tion is not of as good 

 quality as that ob- 

 tained when the heat 

 is applied by means 

 of the jacket. The 

 best results, however, 

 were obtained when 

 both jacket heat and 

 direct steam were 

 used simultaneously. 

 The oil obtained was 

 macerated with 20 

 per cent of its weight 

 of fresh unextracted 

 peel and then filtered. 

 Thus treated, the oil 

 had a lemon -yellow 

 color with a slight 

 tinge of brown. It 

 had an excellent orange odor and the characteristic aromatic orange 

 taste. Apparently the odor-bearing and flavoring constituents are aU 

 present and by the method described a fair grade of orange oil can be 

 prepared. 



PRESSED OIL. 



Pressed orange oil is generally understood to mean the oil which 

 is pressed from the peel by hand. Where labor is cheap such a 

 method of extraction is economically possible, but where labor is 

 relatively costly this method can not be used. Accordingly, methods 

 were worked out for applying heavy pressure without any great 

 outlay of money for hydrauUc presses. 



Fig. 3.— Experimental vacuum still losed in extracting orange oil: A, 

 Still; B, condenser; C, receiver. 



