TECHNOLOGY. 7 19 



Filtering is not essential to the production of high-grade olive oil, but where it is 

 not employed a considerably longer time is required to obtain a perfect racking. It 

 ia believed that one of the errors in the industry is to attempt to bottle the oil too 

 soon. "Where racking alone is depended upon for clarification, oil should not be 

 bottled in a shorter time than 6 months." 



Si une experiments were made in the centrifugal extraction of oil. An examination 

 of the pressed pulp obtained from different factories within the State indicated that 

 the range of recovery is from 35 to 65 per cent of the oil contained in the olive. 

 With a small centrifugal machine about one-half of the liquid and oil contained in 

 the pulp was extracted during the first 5 minutes, and when the operation was con- 

 tinued from 30 to 45 minutes about (>•"> per cent of the total amount of oil in the olive 

 was recovered. 



In these experiments there was a tendency in the beginning for the oil to collect 

 in the center, which later had to be forced through the pulp on the sides of the 

 machine. It was found desirable to loosen the pulp about every 15 minutes. Most 

 of the oil in the pulp was extracted within 30 minutes. After that the oil obtained 

 was not sufficient To compensate for the loss of time unless the mass was loosened 

 from the screen and moistened with water, when increasing results were secured up 

 to about 1 hour. By loosening the pulp and the use of water 61.3 per cent of the oil 

 still remaining in the mass was recovered, an amount sufficient, it is believed, to be 

 well worth the trouble for the time expended. With a large centrifugal similar 

 results were secured. 



"The results taken as a whole and compared with the most effective pressings, and 

 allowance being made for the smaller charges that must be used in the case of the 

 centrifugal as against the large press, can not be considered as offering much encour- 

 agement for manufacturers to adopt the former machine for final work, although it 

 might be used for the preliminary treatment in the removal of water of vegetation 

 and a small amount of oil." 



The centrifugal was found useful in demargarizing oils. Certain varieties of olives, 

 like the Redding Picholine, carry a large proportion of fatty acids which are extracted 

 with the oil. These crystallize out in the case of this variety at 8 to 9° C. and pro- 

 duce a turbid oil at from 11 to 12° C. With oil from good quality of olives the point 

 of turbidity is 4 to .V C. and the point of congelation 2 to 3° C. By cooling these 

 fatty oils down very slowly to 6 or 7° C. and then filtering and separating in the 

 centrifugal machine a better grade of oil can be secured. 



New process of extracting olive oil, J. A. Smith ( C. S. Dept. Com. and Labor, 

 Mo. Consular Rpts., 75 ( 1904 ), No. 287, pp. 113-115).— This article is largely a trans- 

 lation of a pamphlet by A. Funaro on this subject. The new process is essentially 

 as follows: 



" The crushing of the olives in the mill is protracted until a uniform fine pulp is 

 obtained. The pulp is heaped up and the virgin oil which flows from it is collected. 

 The pulp is then passed again through the mill, and afterwards wet with a very 

 dilute solution of carbonate of soda. It is then transferred to a large tank containing 

 alkaline lye and heated to a temperature not exceeding 40° C. (104° F. ). If this 

 were exceeded saponification would be brought about. The contents of the tank are 

 kept in agitation by means of a jet of compressed air. 



"At the end of 6 hours the contents are allowed to settle, the olive pits, washed 

 quite clean, falling to the bottom, while all the fatty matter and lighter particles of 

 the pulp rise to the surface in a kind of emulsion. The olive pits and alkaline liquor 

 being then withdrawn from the bottom of the tank, there is added to this emulsion 

 a cold dilute solution of alum. The compound is again agitated by means of com- 

 pressed air, and an electrical current is {massed through it during some hours. 



