Red cabbage

The red cabbage (purple-leaved varieties of Brassica oleracea Capitata Group) is a kind of cabbage, also known as purple cabbage, red kraut, or blue kraut after preparation. Its leaves are coloured dark red/purple. However, the plant changes its colour according to the pH value of the soil, due to a pigment belonging to anthocyanins. In acidic soils, the leaves grow more reddish, in neutral soils they will grow more purple, while an alkaline soil will produce rather greenish-yellow coloured cabbages. This explains the fact that the same plant is known by different colours in various regions. Furthermore, the juice of red cabbage can be used as a home-made pH indicator, turning red in acid and green/yellow in basic solutions. It can be found in all Europe, throughout the Americas, in China and especially in Africa.On cooking, red cabbage will normally turn blue. To retain the red colour it is necessary to add vinegar or acidic fruit to the pot. Red cabbage needs well fertilized soil and sufficient humidity to grow. It is a seasonal plant which is seeded in spring and harvested in late fall. Red cabbage is a better keeper than its 'white' relatives and does not need to be converted to sauerkraut to last the winter. Red cabbage is often used raw for salads and coleslaw. This vegetable can be eaten cooked. It is the traditional accompanying side dish paired with many German meals, notably döner. At Christmas it can be spiced and served as an accompaniment to seasonal roast goose. Often apples are added to give it sweet-sour taste. It is recommended to start red cabbage seeds indoors 4 weeks before the last frost. Sow in containers that allow for movement of water through the bottom of a cell. Popular seedling starting containers are peat pots, egg cartons, plug trays or milk cartons. Once the seedlings grow to about 2 inches (5.1 cm) tall, and have developed their first leaves, they can be hardened off and moved outside for transplanting. Red cabbage prefers climates that remain moist and cool for most of its vegetative growth stage, so they can be placed in the ground shortly after the last frost, while the spring is still cool. The cabbage plants can be spaced about 12–26 in (30–66 cm) from one another. They will need watering often but are otherwise low maintenance plants. Red cabbage contains an anthocyanin-based dye that can be used as a pH indicator. It is red, pink, or magenta in acids, (pH < 7), purple in neutral solutions (pH ≈7), and ranges from blue to green to yellow in alkaline solutions (pH > 7). Red cabbage has a high content of vitamin C and vitamin K, containing 44% and 72%, respectively, of the Daily Value (DV) per 100-gram amount (right table of USDA nutrient values). Basic research on cabbage phytochemicals is ongoing to discern if certain cabbage compounds may affect health or have anti-disease effects. Such compounds include sulforaphane and other glucosinolates which may stimulate the production of detoxifying enzymes during metabolism. Studies suggest that cruciferous vegetables, including cabbage, may have protective effects against colon cancer. Cabbage is a source of indole-3-carbinol, a chemical under basic research for its possible properties.