Ultrasonic Wave Assisted Maceration Method for Extraction of Red-Purple Pigment from Six Varieties of Red Spinach.

Abstract

Natural dyes have been widely used for coloring food. Red spinach is an alternative resource of red violet color as it is abundant in nature. Despite its simplicity of extraction technique, the maceration method still needs enhancement because it is time-consuming. Ultrasound-assisted extraction (UAE) was used to shorten the extraction time. In this study, the red-violet pigment extraction has been carried out by the maceration method for six red spinach varieties. The spinach leaves' ratio to a mixture of ethanol 96% and citric acid 10% were 1:7, 1:9, 1:11, and 1:13. The highest absorbance for Delima, Abbang, Baret Merah, and Mira extracts were obtained from the ratio of 1:7, whereas Red and Clara extracts were 1:9. The optimum solvent/mass ratio for each variety was then used in the UAE. Extractions assisted by ultrasound in 5, 10, and 15 minutes have been conducted. UAE time yields the highest red-violet extract absorbance in 15 minutes for Red, Abbang, Baret Merah, Mira, and Clara while Delima was in 5 minutes. The results suggested that the UAE is more effective than 24-hours maceration for red-violet pigment extraction from red spinach.