26 



OLIVE OIL AND ITS SUBSTITUTES. 



California oils of known purity of from !!.:> to 31 with an aver- 

 age of 22.5. Blasdale" found the variation on eleven samples of 

 California oils to be from 21 to L'ti . and Colby 6 gives a range of 

 from 21 to 28. On Italian oils the writers found a variation of 

 from 21 to 29.3. Other published results give a variation of 

 23.7 to 29. Milliau'' reports on French oils 24 to 26, but on 

 Algerian' 7 oils gives a range of from 2.8 to 38. This shows that 

 Algerian oils are quite different from the European and Californian 

 products. 



'Fable XV11, prepared from Table XXXV, shows the relation be- 

 twcen the Hiibl number, percentage of solid fatty acids, and melting 

 point of fatty acids in California olive oils. The writers found that 

 in a general way the same relation held good for Italian oils. Milliau^ 

 did not find this relation to hold on oils from Tunis. He found oils 

 with a Hubl number of 88 and a melting point of fatty acids of 

 37 C., and concluded from this that there were fatty acids present 

 more unsaturated than oleic acid. 



TABLE XVII. Relation between Hilbl /,/<//, .W/// />///// //</'//*. <ni<f nn-ltimj in/ml of 

 fatty acids (California oi< 



The melting points of the fatty adds of peanut oil, cotton-seed oil, 

 and lard oil are so much higher than those of the mixed acids of olive 

 oil that any considerable addition of any one of these oils to olive oil 

 would produce an abnormal melting point. This is especially true of 

 lard oil and cotton-seed oil. Sesame oil varies but little from olive oil 

 in respect to the melting point of its fatty acids, but oils of rape seed, 

 mustard seed, sunflower, poppy seed, and maize are appreciably lower. 

 Since, however, none of these would probably be mixed with any 

 but olive oil or some one of the oils having a higher melting point 

 than olive oil. this difference would be of little value in the detection 

 of their substitution for olive oil. The determination of the melting 

 point in itself has little value in the detect ion of adulteration, but is of 

 decided value when taken in connection \\ith other factors in judging 

 whether or not the oil is normal. The melting point.- of the fatty 



"Jour. AHMT. ('In-ill. Boc., lv.'">. 17: '.>'!">. 



^California A>rr. Kxpt. Sta. K<-|>t.. is'.i? .ts. ,,. i ;.. 



''Bui. <lu MiniM.'-iv '! l'.\<:rirultmv. ]s..\ j,. i:;i. 



^Milliau, Bertainchaiul, andMalet, Ra}>|><>rt sur l-s bailee d' olive de Tuniaie, 1900. 



