18 EXPERIMENTS ON PROCESSING PERSIMMONS. 



the exclusion of oxygen is probably the controlling factor, not only 

 in the retention of firmness but in the disappearance of the tannin. 

 Alcohol, while accelerating the rate of processing in some cases, 

 seemed wholly unnecessary, and, as used in experiments 5, 6, and 7, 

 seemed to cause loss in turgor, or crispness, while in some cases, as in 

 experiments 6 and 7, where 25 cc of alcohol were used, superficial 

 injury resulted. 



Experiment 8. — Three small lots of persimmons, Seed and Plant 

 Introduction Nos. 13835, 13841 (Japanese), and No. 22367 (Chinese), 

 fruiting for the first time in this country, were received from Mr. 

 Dorset and from Mr. Bisset, Bureau of Plant Industry, and treated 

 with carbon dioxid. All processed successfully in five days. 



Experiment 9. — Five lots of hard but well-colored native persim- 

 mons (D. Virginiana), picked from different trees in the vicinity of 

 Washington, D. C, were placed in carbon dioxid. After five days 

 the fruits were still excessively astringent. They were again placed 

 in carbon dioxid and examined 10 days later. All of the fruits by 

 this time had softened somewhat and many had decayed. Three 

 of the lots, however, were nonastrmgent before they became very 

 soft, while the controls were astringent until very soft, and thus a 

 slight but perceptible effect due to the processing may be assumed. 



Experiment 10. — In experiment 10 processing was undertaken on a 

 large scale. The fruit was placed in a galvanized-iron can provided 

 with a narrow, deep trough about the upper rim, into which fitted the 

 turned-down edges of the cover. When the trough was filled with 

 water and the cover placed in position, the can was sealed air-tight. 

 The arrangement proved to be not sufficiently positive, however, and 

 it can not be recommended. Sixty-five hard Okame persimmons, 

 purchased on the local market, were processed from November 1 to 

 November 5. All became nonastringent. Sixt} T fruits were firm on 

 November 5 and 5, or 8 per cent, had softened. In the control, con- 

 sisting of 11 fruits, 4, or 36 per cent, were soft. Of the 60 firm per- 

 simmons, 4, or 7 per cent, showed superficial cracking as a result of 

 the humid conditions in the can. Forty-eight of the sound, firm, 

 processed fruits were wrapped and divided into two equal lots. One 

 lot was stored at a constant common-storage temperature of about 

 21° C. (69.8° F.), and the other was kept in cold storage at about 

 2° C. (35.6° F.). A record was made of the rate of softening of each 

 lot. Too few fruits were used for the results to have the degree of 

 validity desirable, but they are of interest in showing the effect of 

 processing on the rate of softening in common and cold storage. The 

 processed fruits kept in common storage softened slightly more 

 rapidly than the control in common storage. Seventy per cent of the 

 processed fruit so stored had softened in nine days after removal from 

 the can, and 63 per cent of the check lot kept at the same temperature 



