KIPENING, STORAGE, AND HANDLING OF APPLES 41 



full-ripe condition regardless of the time required. Since firmness 

 is the outstanding change associated with ripening, the condition of 

 full ripeness was primarily determined by the pressure test. The 

 fruit was placed in the different storage temperatures at the same 

 time and left until the pressure test indicated that it was full ripe 

 for the variety. A slight variation necessarily occurred in the firm- 

 ness of the fruit at the time of sampling, but an attempt was made 

 to have the apples as nearly as possible in a uniform condition. 



From 25 to 30 apples were generally used as a sample for the 

 making of the chemical analyses. After the apples had been tested 

 to determine their firmness, a plug of tissue was removed from each 

 by means of a cork borer and passed through a sampling press of 

 the type described by Clark (5), which pulverized it thoroughly. 

 Fifty-gram samples of this tissue were boiled and made up to 500 

 c. c. with water for acidity determinations. The samples were 

 allowed to stand for three days, about 2 c. c. of toluol being added 

 as a preservative. After three days' standing extraction, the pulp 

 was filtered off through cotton and the acidity determined by titra- 

 tion with N/10 NaOH. Phenolphthalein was used as indicator. 



The 50-gram samples for sugar determinations were boiled in 

 alcohol, CaC0 3 being added prior to boiling to neutralize the acid- 

 ity. These samples were made up to 500 c. c. with 50 per cent 

 alcohol and allowed to stand several weeks for extraction. The 

 pulp was then filtered off and aliquot portions of the filtrate taken 

 for the sugar determinations. The alcohol was evaporated from 

 these portions, the solution cleared with neutral lead acetate, and 

 the sugars determined by Mathews' modification of the Bertrand 

 and Munson and Walker methods (1^ p. 994-). 



The number of days in storage, the pressure test at the end of 

 the storage period, the percentage of sugars both free reducing and 

 total, and the percentage of acidity calculated as malic acid are 

 given in Table 4. Part of the data are for the storage season of 

 1923-24 and part for 1924-25. As heretofore mentioned, the fruit 

 for the season of 1923-24 was picked and held for a certain length 

 of time at 32° F. before being placed in various storage temperatures. 

 In addition to this holding, fruit listed from Yakima, Wash., was 

 shipped by express from that place to the experimental storage plant 

 at the Arlington Experiment Farm, Eosslyn, Va., requiring ap- 

 proximately a week in transit at relatively high temperatures. The 

 fruit used in the 1924^25 experiments was placed in storage at the 

 different temperatures the day following picking. As previously 

 stated, an effort was made to take the apples from the different tem- 

 peratures in similar conditions of hardness, but as will be noted in 

 the column headed "Pressure test (pounds)" some variation existed 

 within the different varieties at the time they were removed from 

 storage. 



It is apparent from the data in Table 4 that in all varieties there 

 was an increase in the quantity of total sugar between the time the 

 fruit was picked and the time it reached prime eating condition at 

 the various temperatures. The 1924^25 fruit placed in storage 

 immediately following picking shows a rather sharp increase in the 

 quantity of sugar present between picking time and when the 

 fruit was full ripe; this increase is apparently due primarily to the 

 change of starch to sugar. 



