Lycium barbarum is rich in anthocyanin, which is a water-soluble pigment. It usually exists in vacuoles of plant cells, and when the cells are damaged, this pigment will dissolve into water.
It is normal to turn purple or light black after soaking in water.
Anthocyanin pigment also has a special property: it turns red when it meets acid and blue when it meets alkali.
When proper amount of vinegar is added to the water soaked in Lycium barbarum, the color will turn dark pink. If a certain amount of alkali or baking powder is added, the color will turn blue-purple. Dyed food will not change like this.
Anthocyanins react with carbohydrates to produce anthocyanins, which are blue or green under alkaline conditions.
Extended information black medlar and red medlar
The efficacy gap between them is not that big.
Lycium barbarum is one of the foods with the same origin of medicine and food. Of course, it is not divided into black and red, and the medicinal value of black and red is the same.
Lycium barbarum is a natural wild plant with the highest anthocyanin content found at present. At first, blueberries were thought to be particularly tall and contained more ingredients than blueberries, so they were regarded as blue wild witches.
References:
People's Network "Black Lycium barbarum bubble" purple liquid medicine ",can I eat it?"
Xinhuanet "Anthocyanin in Purple Potato"