We all know that purple sweet potato is a kind of sweet potato, but it contains a lot of anthocyanins, so it appears purple. In fact, this anthocyanin is a water-soluble pigment, which can be dissolved in water. In the process of boiling purple potato, this pigment will also dissolve in water. If the water is acidic, it will appear purple-red; if it is alkaline, it will appear blue-green, and most of the tap water we usually use is alkaline, which is why the water for boiling purple potatoes is blue.

Purple sweet potato contains anthocyanins, which will change color according to the pH of the environment. If it is acidic, it is purple, neutral environment is purple, and alkaline environment is blue. Your problem may be that the pH of the water changes or something else is added when you cook glutinous rice balls. If you want to cook purple, just add a little white vinegar or lemon juice to the water.

Purple sweet potato is rich in anthocyanins, which will change color when exposed to acid and alkali, purple when exposed to acid and blue-green when exposed to alkali. Tap water is generally alkaline, which is normal and safe to eat.

Health care function of purple sweet potato;

1, which is rich in anthocyanins, prevents many diseases, and has high health care effect and no side effects. The color of purple sweet potato comes from anthocyanin, which is a natural powerful free radical scavenger. A large number of studies have confirmed that anthocyanins have preventive and therapeutic effects on 100 diseases, and their ability to scavenge free radicals is 20 times that of vitamin C and 50 times that of vitamin E. Anthocyanins can scavenge free radicals through the blood-brain barrier, thus protecting brain tissue and reducing the side effects of antibiotics on human body.

2, high selenium and zinc content, anti-oxidation and cancer prevention. Zinc is also a component or activator of many antioxidant enzymes, which can prevent free radical damage and maintain normal immune function. Zinc can also maintain the stability of cell membrane and reduce toxin absorption and tissue damage. The regulation of zinc in tissue metabolism can regulate the synthesis and metabolism of protein, regulate immune function and regulate hormones, such as participating in the synthesis and release of insulin and the secretion of prostaglandin. Zinc is also an essential factor in DNA synthesis, which participates in the division and proliferation of all cells and promotes growth and tissue regeneration.

3, the cellulose content is high, which can promote the digestion of purple sweet potato. These substances can increase the volume of feces, promote gastrointestinal peristalsis, clean up mucus, gas accumulation and corruption in intestinal cavity, discharge toxic substances and carcinogens in feces, keep defecation unobstructed, improve digestive tract environment and prevent gastrointestinal diseases.

4, rich in vitamins, bodybuilding, fitness Purple sweet potato stem tip leaves are rich in vitamins, protein, trace elements, dietary fiber and soluble non-oxidizing substances, and often eat them to lose weight, bodybuilding, fitness and cancer prevention.

5, rich in potassium and iron, oxygen for the body, stable blood pressure.