NUTRITIVE VALUE OF POTATOES 9 



Effect of Variety and Origin 



The results of the tests on the vitamin C content of different varieties of Massa- 

 chusetts potatoes and a comparison of these with potatoes from other states are 

 presented in Table 5. The ascorbic acid content of the same variety grown in 

 different geographical areas was not significantly different. The general average 

 shows that the Irish Cobbler variety was highest; Katahdin, second; Green 

 Mountain, third; and Chippewa lowest. In general, it cannot be said that 

 potatoes from any particular region were either high or low in ascorbic acid 

 content. In many cases, differences between varieties were less than differences 

 within a single variety. 



Effect of Storage 



Eight varieties of Massachusetts potatoes were held in storage for five months 

 One set of each variety was kept in cold storage at 36° F. (2.2° C). A second 

 set was kept in a dry, underground storage where the temperature was controlled 

 by climatic conditions and averaged 40°-50° F. (4.4°-10° C). This would be 

 similar to cellar, or common, storage on a farm. The effect of these storage 

 conditions on the ascorbic acid content of potatoes is presented in Tab'.e 6. 



In two varieties the ascorbic acid content of the potatoes was higher in cold 

 storage than in common storage; in four varieties the reverse was true; and in 

 two varieties there was no difference. However, in every case the tubers held in 

 cold storage were more desirable for eating purposes. 



Storage seemed to cause a leveling off of the differences between varieties in 

 ascorbic acid content. For instance, in October, freshly dug Houma potatoes 

 contained 0.104 milligrams per gram more ascorbic acid than Warba potatoes 

 dug at the same time. After five months of storage the difference in ascorbic 

 acid content of these two varieties was only 0.032 milligrams per gram. 



Table 6. — Effect of Five Months in Storage on Ascorbic Acid Content 



OF Eight Varieties of Mass.\chusetts-Grown Potatoes 

 Cold storage, 36° F. (2.2° C); common storage, 40°-50° F. (4.4°-10° C.) 



Ascorbic .\cid* — mg. per gm. 



Variety 



October 

 1938 



When Dug 



March 1939 



Cold 

 Storage 



Common 

 Storage 



Loss due to Storage — 



percent 



Cold 

 Storage 



Common 

 Storage 



Green Mountain 0.167 0.114 0.120 31 28 



Katahdin 0.120 0.130 0.117 2.5 



Chippewa 0.181 0.085 0.066 53 63 



Irish Cobbler 0.157 0.078 0.107 50 32 



Houma . 250 . 099 . 093 60 63 



Warba 0.146 0.067 0.088 54 40 



Russet 0.161 0.087 0.110 47 31.5 



Golden 0.131 0.079 0.072 39.5 45.0 



♦Mean value of 8 different tubers of each variety. 



