POTATOES - Potatoes are damaged through moisture and heat, as these cause the revival of the potatoes, with consequent sprouting. Good ventilation is also required for the storate and/or stowage of potatoes, as they emit carbon dioxide, which should be cleared, and require oxygen for preservation.
Potatoes shrink through age, and if placed in a dry place the shrinkage will be accentuated through evaporation. If potatoes are stowed or stacked over eight tiers in height the bottom tiers are liable to be damaged by the pressure caused by the heavy weight overstowing same. This specially refers to potatoes in bags or in frail cases and crates.
Sprouting can also be due to the potatoes not having been thoroughly cleaned at origin; soil adhering to the skin of the potatoes accelerates this.
A black soft condition of potatoes may be evidence of poor ventilation in storage or stowage, whereas a black discoloration just below the surface is probably evidence of freezing. In the latter case the vegetable will probably be found in a moist condition. Decay may also produce this moist condition. A green discoloration of the surface can be indicative of undue exposure to strong sunlight either after lifting or in storage.
Potatoes contaminated with the disease Spongospora subterranean may be refused admission to certain countries. The disease is in the form of a mildew of innocent character, which may be dealt with by fumigation, and is not normally regarded as a serious matter except that it may result in a refusal on the part of some countries to permit entry.
The potato belongs to the nightshade family (Solanaceae). It is originally a native of South America (Peruvian-Bolivian Andes and coastal areas) and was known there by AD 200, arriving in Europe in the 16th century. Because of their similarity in appearance to truffles, the Italians named them tartufoli, from which their German name "Kartoffeln" is derived.
Potatoes are the starch-rich tubers of the underground stems (stolons) of Solanum tuberosum, serving to store nutrients for the parent plant.
The following criteria are used in dividing potatoes into their various varieties:
- type of use: table, processing and seed potatoes
- time of harvest: very early varieties (for immediate consumption), early varieties (suitable for potato salads, since not very mealy), medium early varieties (for cellar storage), medium late and very late varieties (of which some are good table potatoes for cellar storage and some are fodder and processing potatoes, since they are often very mealy)
- tuber shape: round, oval, long, long oval or kidney-shaped
- color of flesh: yellow or white
- color of skin: light yellow, ochre-colored to red
- skin texture: rough-skinned, smooth-skinned
Early potatoes are loose-skinned, i.e. they have a thin skin which flakes off easily, causing them to spoil easily.
Mid and late varieties are firm-skinned and therefore more resistant.
Peeled potatoes are composed as follows:
- 16 - 18% starch
- 75 - 78% water
- 2% protein
- 1% minerals
- 1% cellulose
- Commodity Name:
VEGETABLES AND FRUIT (Fresh)