Why do Potatoes turn black?
It is observed that when the potatoes are stored in cool place and then boiled, it tends to turn black. To avoid potatoes turning black they should be stored at 45 degree Fahrenheit or 55 degree Fahrenheit. Keeping the potatoes in the refrigerator might make them look black when they are boiled immediately after taking them out of the refrigerator. The color of potatoes turning black after boiling indicates that they have reacted with the container. If the container used for boiling is aluminum or iron then the potatoes may turn black.
The potatoes when submerged in cold water will keep them away from oxidizing. The black color of the potatoes will result when they come in contact with oxygen. The oxidized potatoes when put in cold water will turn white again. It was noticed that potatoes when kept in too much cold also will tend to turn black. Darkening of potatoes after boiling them was found to be due to oxidation of ferri-chlorogenic acid in the boiled potatoes. The extent of black coloration in potatoes depends on the ratio of chlorogenic acid to citric acid levels. If this ratio is higher, the potatoes look blacker. The molecular approaches were followed to identify the genetic reason behind the blackening of potatoes due to the chemical. Prevention of genetic effects can avoid the potatoes to turn black due to the chemical.
It was also seen that potatoes stored in cool place also make them black even before they are boiled. Raw potatoes turn black when kept exposed to air for long time before cooking. As they possess starch as component and the starch is composed of excess of carbon, potatoes appear black. Carbon is mostly grayish or black in color.