[33] South Carolina Agr. Exp. Sta., Bul. 63, p. 25.
Effect of Storage on Composition.
—Experiments have shown that the quantity of starch diminishes and the quantity of sugar increases on storing. Further, it may be stated that in the varieties of sweet potatoes which are most esteemed for table use there is less starch and perhaps more sugar than are stated in the above examples. In one instance of an analysis made on the 7th of January of stored potatoes, the starch had fallen to a little less than 13 percent, while the sugars had increased to over 11 percent in less than six weeks. The total quantity of fermentable matter, however, as will be seen, had not been greatly changed, although there was probably a slight loss. In the southern agricultural work referred to, the yam and the sweet potato are considered together. The composition and the changes on keeping are well illustrated by the preceding data.
The above data apparently are sufficient to show the high value which attaches to the sweet potato and the yam, not only as edibles, but especially for the purpose of making alcohol. It is also seen that the sweet potato would not be a valuable material for making starch alone, because in starch making the sugar which the sweet potato contains is lost, whereas in the manufacture of alcohol the sugar and the starch, as well as any fermentable celluloses or gums in the potato, are utilized. The following table shows the extent to which this crop is grown in the United States:
Acreage and Production of Sweet Potatoes (Including Yams) in the United States by States, in 1899, As Reported by the Twelfth Census.
| States. | Acres. | Bushels. |
|---|---|---|
| United States | 537,447 | 42,526,696 |
| Alabama | 50,865 | 3,457,386 |
| Arizona | 51 | 4,299 |
| Arkansas | 13,271 | 998,767 |
| California | 1,607 | 239,029 |
| Colorado | 20 | 2,291 |
| Connecticut | 2 | 130 |
| Delaware | 2,265 | 222,165 |
| District of Columbia | 5 | 19,936 |
| Florida | 22,791 | 2,049,784 |
| Georgia | 70,620 | 5,087,674 |
| Hawaii | 135 | 9,284 |
| Idaho | 6 | 413 |
| Illinois | 7,534 | 511,695 |
| Indiana | 3,989 | 239,487 |
| Indian Territory | 1,064 | 80,364 |
| Iowa | 2,688 | 24,622 |
| Kansas | 4,570 | 74,810 |
| Kentucky | 14,178 | 925,786 |
| Louisiana | 27,372 | 1,865,482 |
| Maryland | 6,469 | 677,848 |
| Massachusetts | ..... | 23 |
| Michigan | 71 | 3,242 |
| Minnesota | 4 | 136 |
| Mississippi | 38,169 | 2,817,386 |
| Missouri | 9,844 | 743,377 |
| Nebraska | 551 | 48,224 |
| Nevada | 5 | 923 |
| New Hampshire | 1 | 6 |
| New Jersey | 20,588 | 2,418,641 |
| New Mexico | 47 | 6,180 |
| New York | 73 | 8,681 |
| North Carolina | 68,730 | 5,781,587 |
| North Dakota | ..... | 1 |
| Ohio | 3,796 | 249,767 |
| Oklahoma | 2,512 | 195,799 |
| Oregon | 27 | 2,825 |
| Pennsylvania | 3,443 | 234,724 |
| Rhode Island | 1 | 102 |
| South Carolina | 48,831 | 3,369,957 |
| South Dakota | 3 | 105 |
| Tennessee | 23,374 | 1,571,575 |
| Texas | 43,561 | 3,299,135 |
| Utah | 40 | 4,958 |
| Vermont | 4 | 306 |
| Virginia | 40,681 | 4,470,602 |
| Washington | 52 | 4,672 |
| West Virginia | 3,393 | 202,424 |
| Wisconsin | 4 | 86 |
Average Composition of Sweet Potatoes.
—The mean composition of varieties of sweet potatoes as determined by the California and Texas Experiment stations is shown in the following data:
| California Station (17 varieties). | Texas Station (21 varieties). | |||
|---|---|---|---|---|
| Water, | 69.00 | percent | 70.27 | percent |
| Ash, | 1.15 | „ | 1.14 | „ |
| Protein, | 2.08 | „ | 2.41 | „ |
| Fat, | 1.00 | „ | 0.99 | „ |
| Total sugars, | 5.55 | „ | 6.81 | „ |
| Starch, etc., | 24.23 | „ | 24.00 | „ |
| Crude fiber, | 2.62 | „ | 1.26 | „ |
Included in the starch of the above data are the substances soluble in boiling dilute acid and alkali.