86 



1916 ANNUAL REPORT 



FURTHER INVESTIGATIONS OF THE COMPOSITION AND FOOD 

 VALUE OF THE AVOCADO 



By Prof M. E. Jaffa. University of California 



The data here reported represents the partial results of chemical 

 studies of the avocado which have been carried on at our station. The 

 complete analysis, physical and chemical of each sample is on record 

 and vdll be published later by the University. For the present brief 

 discussion, however, the oil content seems to be the most important. 

 Credit is due to Miss Stover, former assistant in the laboratory, and 

 Mr. Albro, at present associated with the Nutrition Division, for the 

 analytical work. 



The results of 95 analyses are summarized in the accompanying tables. 

 Tables Nos. I and II refer to those varieties which are generally supposed 

 to mature in the late summer and fall and Table No. Ill to those 

 varieties whose season is the first half of the year. In Table No. I the 

 figures relate to but one sample, quite often to but one fruit, while in 

 Table No, II they indicate analyses of two or more samples of the same 

 fruit. The tabulated data might best be discussed under several different 

 heads: 



A. Total amount of oil. 



B. Content of oil in seedlings vs. that in the known varieties. 



C. Oil content of large fruit as compared with that of small fruit. 



D. The development of the oil in the fruit during the ripening 



process. 



A. The toal amount of oil: 



The highest percentage noted , 31.60, is to be credited to the Purdy 

 variety from Whittier. This is a small fruit analyzed on the 9th of this 

 month. It must be remembered, however, that only one fruit was analyzed. 

 It is our intention to make further analyses of the Purdy in order to 

 ascertain whether or not this high percentage w^ill obtain. The nearest 

 approach to the oil content of the Purdy in the spring varieties is noted 

 for the Miller with an oil percentage of 27.45 and the Knowles fro?n 

 Santa Barbara 27.11. If we omit from the discussion the Knowles and 

 the Miller, it will be observed that the spring varieties do not range 

 as high in oil as do the fall varieties. Before such a statement can be 

 considered as a fact, however, it will require more thorough investigation 

 which the station will be only to glad to undertake. Furthermore it 

 will be noticed that more analyses have been made of the fall varieties 

 than of the spring and there are a greater percentage of immature and 

 unripe representatives of the latter class. 



The Chappelow ranks next to the Purdy as far as the oil content is 

 concerned — the Northrop with 27.60 per cent the next highest. The 

 lowest content of oil noted for fruit stated to be fully ripe is in the case of 

 the Beauty from Orange, showing 15.25 per cent. In view of the fact, 

 however, that the determination on the Beauty included but one fruit it 

 will be necessary to make more examinations in order to have enough 



