The invention discloses a formula of a composite natural purple
pigment. The composite natural purple
pigment is prepared from 250 g of beetroot, 25 g of clitoria ternatea flowers, 25 g of peeled lemons and 1,500 g of water. An extraction process comprises the following steps that the beetroot is washed to completely remove sand, peeling is not needed, the air-dried beetroot and peeled lemons arejuiced and filtered by a 100-mesh fine
sieve, then a mixture is put into a pot to be boiled with a big fire and then concentrated with a small fire to the weight required by the formula, and after natural
precipitation, an uppermost pure part is taken for use; fresh red-pulp dragon fruits are peeled, diced, juiced and then filtered by the 100-mesh fine
sieve, a filter residue is put into the pot to be boiled with a big fire and then concentrated with a small fire to the weight required by the formula, and after natural
precipitation, an uppermost pure part is taken for use; water which is 20 times the weight of the clitoria ternatea flowers is added to the clitoria ternatea flowers, after a clitoria ternatea flower liquid is boiled with a big fire, cooking is conducted with a small fire for 10 minutes, sieving is conducted after braising is conducted for 20 minutes, the clitoria ternatea flower liquid continues to be cooked to 1 / 3 of the original volume with a big fire and then is cooked to be in a thick state with a small fire, finally, natural
precipitation is conducted for at least 60 minutes, and an upper pure part is taken for use; the extracted beetroot red
pigment and clitoria ternatea flower blue pigment (a combination of red-pulp dragon fruit red and clitoria ternatea flower blue) are uniformly mixed and loaded into a sterilized dark
essential oil bottle, and the purple natural pigment is formed.