EXPERIMENT STATION RECORD. 



Vol. XXXIV. Abstract Number. No. 3. 



RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



Enzjnns of apples and their relation to the ripening process, R. W. 

 Thatcher (U. S. Dept. Agr., Jour. Agr. Research, 5 (1915), No. 3, pp. 103- 

 116). — From the results of investigations reported from the Minnesota Station 

 it appears that the only enzyms which participate in the changes in the carho- 

 hydrates of apples during the ripening process are oxidases. The juice of the 

 apple contained no diastases, and it appears, tlierefore, that after the starch 

 disappears from the apples the diastases also disappear. None of tlie apples 

 which were available for the investigations contained any starch. No invertase 

 was found, which confirms the findings of Warcollier (E. S. R., 19, p. 307). The 

 presence of none of the other common types of carbohydrate-splitting enzyms 

 could be determined. 



The author concludes that the fact that the changes which take place during 

 the ripening are inliibited by surrounding the fruit with an atmosphere of car- 

 bon dioxid, as shown by the experiments described, is easily explained on the 

 basis of their being oxidase changes, since it is a well-known fact in enzymology 

 that the presence of a large excess of the end products of a reaction generally 

 inhibits the action of the accelerating enzym in an increasing degree as the pro- 

 portion of the end product increases. Carbon dioxid is undoubtedly the end 

 product of oxidase activity, so that the result obtained is what would naturally 

 be expected. Small amounts of esterase and protease which were found in the 

 ripening apples indicate the possibility of the hydrolytic decomposition of the 

 small quantity of essential oil and of protein material contained in the flesh 

 of the apple during the ripening process or subsequent breaking down of the 

 tissue. 



An examination was also made of apple seeds. Diastases were found to be 

 present in considerable amount ; invertase, absent ; emulsin, present in consider- 

 able amount; lipase, present in small amount; protease, present (hydrolyzed 

 both albumins and peptone) ; and oxidases, absent. 



The solidifying and melting' point of mutton tallow and its fatty acids, 

 R. Meldrum {Chem. News, 109 (1914), No. 2827, pp. ^9-51) .—This investigation 

 was undertaken to ascertain the relationship between the melting and solidifying 

 points of mutton tallow and its fatty acids. The thermometer-bulb method was 

 used for the melting point, and the solidifying point was determined by Dalican's 

 method. 



The author has demonstrated that mutton and beef tallow do not possess a 

 constant solidifying point for any given sample. Experimental data submitted 



201 



