| 摘要: | Betalain is a group of active compounds which exist in pulp red dragon fruit and peel of redand white dragon fruit. In recent year, betalain has been applied to several industries such as food,pharmaceutical cosmetics, and etc., due to its beneficial properties to health and attractive colors.Nevertheless, betalain is easy to degrade under extreme pH, light, and high temperature.This research is therefore focused on the extraction of active compounds from peel and pulpof red dragon fruit and Thailand’s white dragon fruit, the antioxidative capacity by DPPH assay, themicroencapsulation of crude extract with alginate/chitosan, and the stability of crude extract solutionsand encapsulated betalain (solution and particles) under various storage conditions; 4°C, 25°C (withlight), and 45°C.The results show that yield percentage of all crude extracts are between 1.62 and 7.86%,, thebetalain content (betacyanin and betaxanthin) are between 3.32 and 23.43 mg/L, and the antioxidativecapacity as 50% inhibitory concentration by spectrophotometric method and HPLC screening methodare 0.37-0.62% (w/v) and 0.14-0.59% (w/v), respectively. The stability test results show that light andhigh temperature are critical factor to betalain degradation, microencapsulation can increase thestability of betalain. The characterization of encapsulated betalain of all samples in terms of particlesize, polydispersity index, zeta potential, encapsulation efficiency (betacyanin and betaxanthin), andloading percentage (betacyanin and betaxanthin) are 0.82-1.61 μm, 0.557-0.831, -47.4 to -51.4 mV,13.32-37.87%, and 0.26-2.79%, respectively. Moreover, the encapsulated particle is more stable thanencapsulated solution in high temperature condition that means the encapsulated particle could bemore stable during storage. Since the production of lipstick might use higher temperature to processthus encapsulated particle seems to be a good raw material for applying in the lipstick formulationthan other forms. |
