July 15, 1919 



Carbohydrate Metabolism in Green Sweet Corn 1 45 



Table III. — Sugar loss from green sivect corn during different periods of storage at different 

 temperatures , expressed as percentages of the same initial sugar at all temperatures 



TOTAL SUGARS 



24. 

 48. 

 72. 

 96. 



Number of hours in storage. 



Per cent. 

 8. 12 



14- 51 

 18.03 

 22. 00 



Storage temperature. 



3°C. 



Per cent. 

 16.98 



27-95 

 38.71 

 49.22 



Per cent. 

 25. 61 

 45-73 



55- 50 

 62. 10 



30° C. 40° c 



Per cent. 

 50. 28 



57-09 

 59. 00 

 61. 84 



Per cent. 



45-79 

 60. 15 

 62. 16 



24. 

 48. 

 72. 

 96. 



31-05 



56. 12 

 64. 2 2 

 70. 16 



59-42 

 66.76 



68.55 

 70. 19 



51-03 

 64.68 

 69. 24 



KREE-REDUCING SUBSTANCES AS INVERT SUGAR 



24. 

 48. 

 72. 

 96. 



7-58 



13. 61 



14. 62 

 16.97 



29. 96 



36. 19 



39-74 

 43- 19 



33.48 

 49.76 

 49.76 



The data in Table III, showing the rate of actual loss for total sugars 

 and sucrose, were plotted as curves (fig. i and 2). 



The curve for 0° C. shows a more rapid sugar loss than is typical for 

 this temperature. In the first place, it required some time for the corn 

 to cool down to this temperature. At the end of each 24-hour period a 

 pair of ears were removed from the cold chamber in order to take the first 

 set of samples. Although the sampling period was short, the temperature 

 of the corn would soon rise a few degrees above 0°. The loss of sugar 

 at the sampling temperature is accumulative in the curve. 



The inversion of sucrose appears to be the controlling process in the 

 sugar loss, as the curves for the decrease of sucrose are very similar to 

 those for the loss of total sugar. 



Temperature coefficient. — Since the curves in figures i and 2 all 

 start from the same point, by means of a simple graphic method the 

 relative rates of sugar loss at the different temperatures can now be 

 determined by comparing the times at different temperatures required 

 to do the same amount of work. As an illustration we will choose a 

 stage in the depletion of sugar- when 40 per cent of the total sugar is lost; 

 in other words, at this point the sugar in the corn is 40 per cent less 

 than at the beginning of storage. A horizontal line is drawn from 

 108124°— 19 2 



