It is not anthocyanin. They are similar in color, but different in chemical structure. They are two different pigment components. Beet pigment and anthocyanin generally cannot exist in the same angiosperm at the same time. Beet pigment only exists in the peel of white pitaya, not in the pulp, but in the pulp and peel of red pitaya.
Although there is pigment in red pitaya, this pigment is not only harmless to human body, but also has anti-oxidation and anti-free radical effects, which is good for human skin. And many foods contain anthocyanins and lycopene, such as grapes, blueberries and eggplant.
Physical and chemical properties of beet pigment
β -carotene is reddish purple to deep purple liquid, block or powder or paste, soluble in water, insoluble in acetic acid and propylene glycol, insoluble in ethanol, glycerol and oil. The maximum absorption wavelength of betanin is 538nm. Beet pigment is soluble in water, reddish purple and stable in the range of pH 4.0 ~ 7.0. When the pH value is less than 4.0 or more than 7.0, the color of the solution changes from red to purple. When the pH value exceeds 10.0, the color of the solution turns yellow rapidly, and at this time, betacyanin is converted into betaxanthin.
Light, oxygen and metal ions can promote its degradation. Water activity has a great influence on the stability of beet pigment, and its stability increases with the decrease of water activity. Ascorbic acid has a certain protective effect on lycopene.