704 EXPEEIMENT STATION RECORD. 



"The more imnicature fruits heated to 70° for 10 minutes or longer darliened 

 nicely but remained astringent. At higher temperatures even the more mature 

 fruits remained permanently astringent while untreated immature fruits gradu- 

 ally lost their astringency. These facts can he explained only as the direct or 

 indirect action of some specific enzym that is destroyed at about 70°. Hydra- 

 zine hydrochlorid interfered with the general trend of riiieiiing but the 

 astringency dlsapiieared. 



" Commercially, many varieties of dates may be ripened rapidly after they 

 have reached a certain degree of maturity. Before that time tliey do not con- 

 tain suflicient dry matter to make a palatable fruit. Many varieties so ripened 

 are fully equal to the natural product. This may be accomplished by exposing 

 them to the vapors of a great many substances, but only a few are commer- 

 cially practical, due to the bad flavors which most of them impart. Fruit of 

 good flavor was obtained by treatment with the vapors of acetic and propionic 

 acids, ethyl chlorid. ethyl bromid, ethylene chlorid, methylene chlorid and 

 chloroform, and with solutions of lactic, benzoic and salicylic acids and some 

 other substances of more or less poisonous nature. Gasoline, benzene, esters of 

 organic acids, ordinary ether, acetone, volatile oils, and most other substances 

 leave permanent disagreeable flavors. 



" Deglet Noor dates do not yield satisfactorily to these methods but can be 

 made palatable and, if sufficiently mature, will yield fruit of fair quality when 

 subjected to the judicious use of ethyl nitrite vapor. A small amount of this 

 reagent (| to 4 cc. of 20 per cent solution for every 1,000 cc. of space inclosed) 

 will finally render the tannin insoluble without discoloring the date badly or 

 imparting any noticeable flavor. 



" It is anticipated that the application of these methods will prevent much 

 of the enormous loss from souring which, is experienced at present during 

 unfavorable weather. Artificially ripened dates do not sour so readily as the 

 fruit ripened on the tree and remain much freer from insects." 



Concerning' the after-ripening- of fruits, R. Otto and W. D. Kooper (Ztschr. 

 Untcrsiich. Nalu: u. GenussvitJ., 19 {19 10), No. 1, pp. 10-13; abs. in Biochcm. 

 Centbl, 9 (1910), No. 18-19, p. 830).— Investigations with the sloeberry ( Primus 

 spinosa) show that the total sugar content of the dry substance increases very 

 little, but does so at the expense of the glucose and results in a rise in the 

 fructose content. The acid and tannin decrease about in the same proportion, 

 but this decrease is greater than the increase in the total sugar content. The 

 authors, therefore, conclude that there is no ground for the belief that the 

 after ripening is brought about with the production of sugar at the expense 

 of the other substances present. Furthermore, it is explained that the diminu- 

 tion in the astringency is due to the decrease in the acid and tannin. 



Postripening' of fruits, R. Otto and W. D. Kooper (Ztschr. Untersuch. NaJir. 

 u. Genussmtl., 19 (1910), No. 6, pp. 328-330 ) .—Further investigations with other 

 fruits, the Japanese quince (Cijdotiia japonica) and the medlar (Mispelus 

 germanioa), showed that with the latter a decided decrease in the sugar took 

 place simultaneously with the decrease in the acid and nitrogen content. With 

 the Japanese quince in the second stage of ripening a decrease in the sugar 

 was also apparent, but the tannin and acid decreases were slight. In the third 

 stage, however, a marked fall in the water, sugar, tannin, and acid content 

 took place. 



The chemical novelties for 1909, C. Poulenc (Lcs Nouvcaut^s Chimiqncs 

 pour 1909. Paris, 1909, pp. VIII +336, figs. 172).— A condensed description of 

 new or modified chemical apparatus and methods brought out in the year 1909. 

 The apparatus included is physico-chemical, analytical, general industrial, food, 



