STORAGE OF FRUITS, VEGETABLES, AND FLORISTS' STOCKS 11 



any given temperature. Recent investigations (30) indicate that cal- 

 culations made on this assumption give values that are within 10 per- 

 cent of those obtained calorimetrically. 



The assumption has also been made, although it is believed to be 

 only approximately correct for fruits and vegetables, that the rate 

 of temperature drop at any given time during cooling is proportional 

 to the difference between room temperature and fruit temperature 

 at that time. With this assumption as a basis, the temperature and 

 thus the rate of respiration at any time during the cooling period, as 

 well as the total heat produced during the whole cooling period, have 

 been calculated. 3 



Table 2. — Approximate amovmts of heat of respiration and sensible 

 heat to be removed from certain fruits in cooling them from 60°, 70°, 

 or 80° to 35° F. in a room at 32°, when the cooling takes place in 

 3, h 5, 6, #, or 10 days 



Kind of fruit 



Apples: 

 Winesap . 



Grimes Golden. 



Peaches : 



Elberta _•_ 



Carman 



Pears : 



Bartlett 



Strawberries : 

 Chesapeake 



Howard 17 



Oranges: 



Florida seed 

 ling* 



Initial 

 tem- 

 pera- 

 ture 



Heat of respiration per ton of fruit during- 



3 days 



B. t. u. 

 8,000 

 7,000 

 6,000 



12, 000 

 10, 000 



8,000 



13, 000 

 10, 000 



7,000 

 16, 000 

 13, 000 

 10, 000 

 16, 000 

 13, 000 



30, 000 



24, 000 

 19,000 

 38, 000 



31, 000 



25, 000 

 9,000 

 8,000 

 6,000 



4 days 



B. t. u. 



11,000 

 9,000 

 8,000 



16, 000 

 13, 000 

 11,000 

 18, 000 

 13, 000 

 10, 000 

 22, 000 



17, 000 

 13, 000 

 22, 000 

 17, 000 

 39, 000 

 32, 000 

 26, 000 

 51, 000 

 42, 000 

 34, 000 

 12, 000 

 10, 000 



9,000 



5 davs 



B. t. u. 



14, 000 



12, 000 

 10, 000 



20, 000 

 17, 000 



13, 000 

 22, 000 

 17, 000 



12, 000 

 27, 000 



21, 000 

 16, 000 

 27, 000 



22, 000 

 49, 000 

 40, 000 

 32, 000 

 64, 000 

 52, 000 

 42, 000 



15, 000 



13, 000 

 11,000 



6 days 



B. t. u. 

 16, 000 

 14, 000 

 12, 000 



24, 000 

 20, 000 

 16, 000 

 26, 000 

 20, 000 



14, 000 



32, 000 



25, 000 

 19, 000 



33, 000 



26, 000 

 59, 000 

 49, 000 

 39, 000 

 77, 000 

 63, 000 

 51, 000 

 18, 000 



15, 000 

 13,000 



8 days 



B. t. u. 

 22, 000 

 19, 000 



16, 000 

 32, 000 

 26, 000 

 21, 000 

 35, 000 

 26, 000 



19, 000 



43, 000 



34, 000 

 25, 000 



44, 000 



35, 000 

 79, 000 

 65, 000 

 51, 000 



102, 000 

 84, 000 

 68, 000 

 24, 000 



20, 000 



17, 000 



10 days 



B. t. u. 

 27, 000 



23, 000 

 20, 000 

 40, 000 

 33, 000 

 27, 000 

 44, 000 

 33, 000 



24, 000 

 54, 000 



42, 000 

 32, 000 

 54, 000 



43, 000 

 99, 000 

 81, 000 

 64, 000 



128, 000 

 104, 000 

 84, 000 

 30, 000 

 26, 000 

 22, 000 



Sensi- 

 ble 

 heat l 



B. t. u. 

 80, 000 

 62, 000 

 44, 000 

 80, 000 

 62, 000 

 44, 000 

 80, 000 

 62, 000 

 44, 000 



80, 000 



62, 000 



44, 000 

 61, 000 

 43, 000 

 83, 000 

 64, 000 

 46, 000 

 83, 000 

 64, 000 

 46, 000 



81, 000 



63, 000 



45, 000 



1 For any one kind of fruit at a given temperature these figures are assumed to 

 be the same for all cooling periods included in the table. 



2 The rate of respiration is practically the same for both Florida seedling oranges 

 and California navel oranges. 



3 The authors wish to acknowledge the valuable assistance given by W. V. 

 Hukill, Division of Farm Buildings and Rural Housing, Bureau of Plant Industry, 

 Soils, and Agricultural Engineering, in making the calculations and in preparing 

 this statement on the production of heat by fruits and vegetables. 



