The effect of basic ingredients form, cold storage and precipitate separation on bioactive components and antioxidant activity of Curcuma xanthorrhiza Roxb

Curcuma xanthorrhiza Roxb water extract is like temulawak drinks, are easily precipitated when stored in cold temperatures (refrigerator). This study aimed to determine the effect of basic ingredients form, cold storage and precipitate separation of water extract on the bioactive components and antioxidant activity of the C. xanthorrhiza water extract. The bioactive components qualitatively observed were tannins, flavonoids, glycosides, terpenoids, and saponins. Furthermore, curcumin, flavonoids, total phenolic, and antioxidant activity were quantitatively analyzed. Antioxidant activity was carried out by testing the capacity of DPPH radical scavenging. The capacity of free radical scavenging, total phenol, flavonoids and curcumin from water extract of C. xanthorrhiza from fresh rhizome without cold storage and without separation of the precipitate was the largest compared to other treatments, were 76.39%, 1.68 mg/mL, 2.47 mg/mL and 0.71 mg/mL, respectively. Separation of the precipitate from C. xanthorrhiza water extract reduces curcumin, flavonoid contents, total phenols and DPPH radical scavenging capacity