STORAGE OF FRUITS, VEGETABLES, AND FLORISTS' STOCKS 



9 



As a result of these calculations it has been found that the heat 

 produced by the respiration of fruit while it cools is directly pro- 

 portional to the length of the cooling period. The figures for cool- 

 ing periods of 3, 4, 5, 6, and 8 days are therefore set at 3, 1, 5, 6, 

 and 8 tenths (to the nearest thousand) of the figure for 10 days. 

 The specific heat has been calculated by the formula #=0.008 a + 0.20, 

 in which S signifies the specific heat of a substance containing a per- 

 cent of water; 0.20 is the value that has been assumed to represent 

 the specific heat of the solid constituents of the substance in question 



Table 2. — Approximate amounts 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° F., when the cooling takes place in 3, J h 5, 6, 8, or 10 days 



Kind of fruit 



Initial 

 tempera- 



Heat of respiration per ton of fruit during — 



Sensible 















heat > 





ture 



3 days 



4 days 



5 days 



6 days 



8 days 



10 days 





Apples: 



O F 



B. t. u. 



B.t.u. 



B. t. u. 



B. t. u. 



B.t.u. 



B. t. u. 



B.t.u. 





f 80 



8,000 



11,000 



14, 000 



16, 000 



22, 000 



27, 000 



80, 000 



Winesap.. 



\ 70 



7,000 



9,000 



12, 000 



14, 000 



19, 000 



23, 000 



62, 000 





60 



6,000 



8,000 



10, 000 



12, 000 



16, 000 



20, 000 



44, 000 





80 



12, 000 



16, 000 



20, 000 



24, 000 



32, 000 



40, 000 



80, 000 



Grimes Golden.. 



{ 70 



10, 000 



13, 000 



17, 000 



20, 000 



26, 000 



33, 000 



62, 000 





60 



8,000 



11,000 



13, 000 



16, 000 



21,000 



27, 000 



44, 000 



Peaches: 



80 



13, 000 



18, 000 



22, 000 



26, 000 



35, 000 



44, 000 



80, 000 



Elberta... 



{ 70 

 I 60 



10, 000 

 7,000 



13, 000 

 10. 000 



17. 000 

 12, 000 



20, 000 

 14, 000 



26, 000 

 19, 000 



33, 000 

 24, 000 



62, 000 





44, 000 





80 



16, 000 



22, 000 



27, 000 



32, 000 



43, 000 



54, 000 



80, 000 



Carman.. 



< 70 



13, 000 



17, 000 



21, 000 



25, 000 



34, 000 



42, 000 



62, 000 





60 



10, 000 



13, 000 



16, 000 



19, 000 



25, 000 



32, 000 



44, 000 



Pears: 



f 70 

 \ 60 



16, 000 



22, 000 



27, 000 



33, 000 



44, 000 



54, 000 



61,000 



Bartlett 



13, 000 



17, 000 



22, 000 



26, 000 



35, 000 



43, 000 



43, 000 



Strawberries: 



Chesapeake 



80 



30, 000 



39, 000 



49, 000 



59, 000 



79, 000 



99, 000 



83, 000 



70 



24, 000 



32, 000 



40, 000 



49, 000 



65, 000 



81, 000 



64, 000 



60 



19, 000 



26, 000 



32, 000 



39, 000 



51,000 



64, 000 



46, 000 





80 



38, 000 



51,000 



64, 000 



77, 000 



102, 000 



128, 000 



83, 000 



Howard 17 



\ 70 



31, 000 



42, 000 



52, 000 



63, 000 



84, 000 



104, 000 



64, 000 





{ 60 



25, 000 



34, 000 



42, 000 



51, 000 



68, 000 



84, 000 



46, 000 



Oranges: 



Florida seedlings 2 



| 80 



9,000 



12, 000 



15, 000 



18, 000 



24, 000 



30, 000 



81, 000 



{ 70 



8,000 



10, 000 



13, 000 



15, 000 



20, 000 



26, 000 



63, 000 



[ 60 



6,000 



9,000 



11, 000 



13, 000 



17, 000 



22, 000 



45, 000 



i 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. 



Column 1 of table 2 shows the kind and variety of fruit and col- 

 umn 2 the temperature of the fruit at the time cooling started, in a 

 room held at 32° F. The next column shows the amount of heat 

 evolved by respiration if the fruit reaches 35° at the end of 3 days. 

 The next five columns show the amount of heat if cooling to 35° re- 

 quires 4, 5, 6, 8, or 10 days, respectively. The last column is the 

 sensible heat (obtained by multiplying the specific heat of the fruit 

 by the difference between initial and final temperatures and this 

 result by the number of pounds in a ton). For any one kind of 

 fruit at a given initial temperature, the specific heat is assumed to be 

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



The values given in table 2 are only approximate. However, in 

 view of the results of the investigation mentioned on page 8, it is 

 believed that the two assumptions that have been made — namely, (1) 

 that the heat of respiration is produced only by the oxidation of a 



324484°— 41 2 



