PKODUCTION OF SWEET-OEANGE OIL. 9 



COMPARISON OF THE VARIOUS OILS. 



In order that the oils obtained by the processes outlined might be 

 compared with commercial imported Italian hand-pressed oil, a 

 sample of the latter was purchased in the open market, and the 

 results of the comparison are shown in Table V. 



Table V. — Comparison of the oils obtained by vacuum distillation and by pressing with 

 a commercial sample of hand-pressed imported oil. 



Description 

 ofofl. 



Color. 



Odor. 



Taste. 



Specific 

 gravity, 

 at25°C. 



Specific 



rotation 



(Wd), at 



25° C. 



Evap- 

 oration 

 residue. 



Total 

 absorp- 

 tion by 

 sodium 



bisul- 

 phite. 



Italian band 

 pressed. 



Florida: 



Vacuum 

 distilled. 



Machine 

 pressed. 



Lemon yellow. 



Lemon yellow, 

 with slight 

 brown tinge. 



Reddish yel- 

 low. 



Characteristic 

 orange. 



do 



Characteristic 

 orange; excel- 

 lent fruity 

 aroma. 



Characteristic, 

 aromatic; no 

 bitterness. 



do 



do 



0. 841.5 



.842.3 

 .8445 



115° 6' 



115° IS' 

 109° 36' 



Per cent. 

 1.73 



2.10 

 2.90 



Percent. 

 2.92 



2.66 

 4.00 



Sweet-orange oil is graded on the market according to its color, 

 odor, taste, specific gravity, and angle of rotation. The ninth 

 decennial revision of the United States Pharmacopoeia describes 

 orange oil as a yellow liquid, having the characteristic odor and taste 

 of orange peel. The specific gravity, at 25° C, lies between 0.842 and 

 0.846; the optical rotation is not less than +94° in a 100-mm. tube 

 at 25° C. 



Table V reveals some interesting comparisons. The color of the 

 pressed oil as given is reddish yellow, due entirely to coloring matter 

 which was forced out by the heavy pressure used in extracting the 

 oil. This color in no way interferes with the commercial uses of the 

 oil and is not detrimental to its sale. The odor, on comparison, 

 shows that the pressed oil is somewhat superior to the vacuum- 

 distiUed oil and also to that of the commercial sample. It possesses 

 the characteristic odor of orange peel, and in addition has a nne, 

 fruity, very agreeable aroma. In all the samples, the oils possessed 

 a fine, characteristic, aromatic taste. The specific gravity of the 

 sample bought in the open market is slightly below that stated in 

 the Pharmacopoeia as the minimum limit. The vacuum-distilled 

 and pressed oils are safely within the limits. The angles of rotation 

 of the commercial sample and the vacuum-distilled oils agree very 

 closely; that of the pressed oil is somewhat lower, indicating that 

 this sample probably contains more of the valuable optically inactive 

 constituents and less of the optically active limonin. The residue 

 50399°— Bull. 399—16 2 



