Even if your potatoes look healthy and appetizing at first glance, the tubers can darken during cooking. If you do not follow some rules of growing, harvesting and storage, melanin is formed in potatoes, which causes a change in the color of the pulp of the tubers. But don't worry - unlike solanine (when the potatoes turn green), melanin does absolutely no harm to the body. But eating such potatoes naturally does not give much pleasure. Why is this happening?
Darkening of tubers occurs if potash or nitrogen-containing fertilizers were incorrectly applied. Potassium is harmful both in excess and in insufficient quantities, and nitrogen is especially dangerous when it is in excess in the soil. Therefore, mineral fertilizers must be applied strictly in accordance with the norms.
To grow potatoes, it is important to maintain moderate soil moisture and moderate air temperatures. In hot summers with little rainfall, as well as in rainy summers, the soil becomes dense. In these cases, weeding and hilling of bushes is necessary for potatoes, then oxygen will be supplied to the tubers in sufficient quantities. The lack of oxygen subsequently causes the potatoes to darken.
… Discoloration of potatoes can cause mechanical damage to agricultural implements (bruises, punctures, cracks) during harvesting, transportation and storage. Therefore, this stage of growing potatoes must be treated responsibly.
The optimum storage temperature for potato tubers is + 3- + 4 degrees. C. Storage in warmer conditions (+ 10- + 15 deg. C) or, conversely, at lower thermometer values (up to 0- + 1 deg. C), as well as with a lack of oxygen or supersaturation of carbon dioxide in the storage contributes to darkening tubers.
Peeled tubers must be immediately immersed in water. Potatoes must not be boiled in aluminum or enameled ones with defects in the coating. During cooking, tubers should be covered with water, as wet starch darkens in air. When cooking, you can put bay leaves in a saucepan.
