摘要：The extraction of anthocyanins present
in the skin of the dragon fruit was performed using trifluoroacetic acid (TFA)
plus a mixture of methanol, acetic acid and water; the anthocyanins were then
purified with a LC-18 cartridge, using methanol acidified with TFA as eluent,
reaching concentrations of 44.3865 ± 1.3125 mg/100g of sample. The extracts were put through stability tests
under different storage conditions, modifying the pH of the extracts (pH of 1,
4 and 6), the temperature (4℃, 25℃ and 68℃) and the absence and presence of light for a time
period of 4 days; the tests indiated that anthocyanins remain more
stable at a temperature of 4℃ with a pH of 4 in the absence of light, retaining up to 80% of the
pigment. Three anthocyanins were partially identified in the extracts by high
performance liquid chromatography (HPLC); they were: cyanidin 3-O-glucoside, cyanidin 3,5
O-glucoside and pelargonidin 3,5 O-glucoside.
