A STUDY OF SWEET POTATO VARIETIES. 
21 
Table 4. — Results of chemical analyses of samples of four varieties of sueet 
potatoes canned at intervals of 10 days during curing and storage. 
Constitutents (pet cent). 
Sample. 
Mois- 
ture. 
Sugar content (calculated 
as invert). 
Dry 
weight. 
Reducing 
(before in- 
version). 
Nonre- 
ducing. 
Total. 
Total 
polysac- 
charids 
j (calcu- 
i lated as 
! starch). 
Dextrin. 
Big-Stem Jersey: 
Freshly dug 
After curing 10 days . 
After storage— 
10 davs 
20 days 
Nancy Hall: 
Freshly dug 
After curing 10 davs. 
After storage— 
10 days 
20 days 
Southern Queen: 
Freshly dug 
After ciuing 10 days . 
After storage— 
lOdays 
20 days 
Porto Rico: 
Freshly dug 
After curing 10 days. 
After storage — 
10 davs 
20 days 
66. 
62 
68. 
27.37 
28.49 
28.77 
29.60 
33.20 
33.20 
35.40 
34.89 
28.91 
31.38 
31.45 
31.43 
29.97 
30.85 
31.22 
31.80 
6.50 
5. 65 
6.03 
6.11 
9.17 
9.76 
10.57 
10.38 
7.67 
8.18 
9.08 
S.39 
6.75 
8.90 
2y 
2.15 
4.15 
4.59 
4.51 
1.89 
4.23 
4.51 
4.65 
1.38 
3.74 
3.02 
3.70 
1.83 
4.88 
5.34 
4.88 
8.65 
9.80 
10.62 
10.62 
11.06 
13.99 
15.08 
15.03 
9.05 
11.92 
12.10 
12.09 
8.58 
13.78 
13.63 
13.74 
10.85 
10.31 
10.39 
10.36 
11.02 
8.51 
10.64 
9. 53 
10.14 
9.06 
11.06 
7.65 
8.44 
9.13 

0.41 
.32 
4.78- 
5. IS 
5.11 
.17 
1.33 
4.73 
3.7S 

3.92 
3.88 
3.66 
From Table 4 it will be seen that the moisture content of the 
canned product is highest in the lots canned immediately after 
digging, those canned at the end of the storage period of 20 
days showing a loss of from 1.6 to 2.5 per cent. The total 
sugar content increases in the succeeding tests and the total 
polysaccharids, calculated as starch, decrease, but these changes seem 
insufficient to account for the enormous change in plasticity. 
The dextrin content of the samples is of interest. In the Big-Stem 
Jersey none was found in the material canned from freshly dug 
potatoes, and only a relatively small amount in any of the lots canned 
subsequently. In the Nancy Hall there was a small amount of dex- 
trin in the material from the freshly dug potatoes and this quantity 
greatly increased in the material from the cured and from the stored 
potatoes. The Southern Queen showed a small dextrin content in 
the lot from the freshly dug roots, a larger amount in material cured 
for 10 days, though less than is formed in the corresponding lots of 
Nancy Hall and Porto Eico, and a considerable amount in the lots 
from stored potatoes. The figures for the Porto Rico are similar 
to those for the Nancy Hall except that no dextrin is found in ma- 
terial from the freshly dug potatoes and the figures in the succeeding 
iots are somewhat lower. From qualitative tests made in connection 
with these studies but not recorded here it seems almost certain that 
