Experimental principle: this is because the purple kale contains anthocyanins, anthocyanins in the alkaline environment is blue, in the acidic environment is red, so purple kale juice can be used as a kind of acid-base indicator.

1, photosynthesis and chlorophyll: Chlorophyll is an important pigment in plants, which can absorb light energy from sunlight and convert it into chemical energy, thus providing energy for plant growth. In the spring and summer months, when there is plenty of light, purple kale has a higher chlorophyll content and appears bright green.

2, anthocyanin synthesis: In the growth process of purple kale, anthocyanin is a very important pigment. When purple kale is affected by unfavorable environmental conditions such as low temperature, its internal biochemical reaction will change, resulting in increased anthocyanin synthesis.

Anthocyanin is a water-soluble pigment that alters the distribution of water within the cells of the purple kale, causing the water within the cells to move toward the vesicles, which leads to swelling of the leaf tissue and gives the purple color to the purple kale.

3, the influence of environmental factors: purple kale discoloration is also closely related to environmental factors. For example, temperature, humidity, light and so on will affect the color change of purple kale leaves. Generally speaking, the lower the temperature, the greater the humidity, the shorter the light time, the faster the purple kale leaves change color. In addition, the nutrients in the soil also affect the color of purple kale leaves.

The relationship between purple kale discoloration and hot and cold water

The relationship between purple kale discoloration and hot and cold water, anthocyanin is a natural water-soluble pigment, which appears red in an acidic environment and blue or purple in an alkaline environment. When the cells of purple kale are damaged, the anthocyanins in them are released from the cells, causing purple kale to turn red. If the pH of the purple kale changes.

When purple kale is alternately soaked in hot and cold water, the hot water raises the pH of the purple kale while the cold water lowers the pH. This change in pH causes a change in the solubility of anthocyanins, which changes the color of the purple kale from red to purple or blue.

The rate at which purple kale changes color is also temperature dependent. In general, high temperatures accelerate the release and dissolution of anthocyanins, causing the color of purple kale to change more quickly. If you want to slow down the discoloration process of purple kale, try chilling it in the refrigerator for a while. The color change of purple kale is related to both hot and cold water and temperature.