Curcuminoids extraction from turmeric (Curcuma longa) using ultrasound-assisted extraction as anti-browning agents

The purpose of this research was to extract curcuminoids from Turmeric (Curcuma longa) which are used to prevent browning in the fresh-cut fruit. Turmeric was extracted using ultrasound-assisted extraction (UAE) with 95% of ethanol. The power was varied at 160, 280 and 400 W for 10 min. Turmeric extracted by UAE with 95% of ethanol at 160W had the highest total curcuminoid, total phenolic and total flavonoid contents of 360.50 mg g -1 crude extract content, 312.03 mg GAE/g crude extract and 1,598.89 mg QE g -1 crude extract. Moreover, this extract had the highest curcuminoid derivatives, such as curcumin I, demethoxycurcumin and bisdemethoxycurcumin at 104.71, 72.82 and 91.36 mg g -1 crude extract, respectively. Then, the extract was encapsulated with 30% gum arabic (wall material) by spray drying at 130, 150 and 170°C. The result showed that water evaporated rapidly at 170°C, resulting in a perfectly rounded external surface. The total curcuminoids, phenolics and flavonoids of encapsulated powder were 33.68 mg g -1 crude extract, 37.70 mg GAE g -1 crude extract and 126.76 mg QE g -1 crude extract, respectively. The encapsulated curcuminoids significantly inhibited tyrosinase with an IC50 of 10,698 ppm, which were applied to fresh-cut apple at concentration of 0, 0.05, 0.1, 0.25, 0.5, 1 and 2% (w/v). All samples were packed in closed containers polypropylene (PP) and stored at 4 °C. The sensory evaluation of fresh-cut apple dipped with 0.25% (w/v) encapsulated curcuminoids had acceptability scores for the least curcumin odor, without severity of browning, and moderate sweetness and bitterness. The quality of fresh-cut apple could be maintained for 5 days.