Coloring potential of anthocyanins from purple sweet potato paste: Ultrasound-assisted extraction, enzymatic activity, color and its application in ice pops

Abstract

Color in food represents an important parameter of quality. This investigation aimed to extract anthocyanins from purple sweet potato using the ultrasound technique, and their application in a food product. The extract obtained at pH 2.5, 60% amplitude and 10 min presented the highest content of anthocyanins, the highest phenolic content, best color properties and lowest residual activity of enzymes. A response optimization analysis was performed, where the experimental results matched the predicted values in the optimal sample. This optimal extract was added as a natural anthocyanin-colorant in ice pops, which were stored and analyzed for one month. The anthocyanins content in ice pops was kept at 80% until day 21, and the pH, soluble solids, and color properties did not presented changes during storage. Concluding that the natural colorant had similar stability to the synthetic colorant. The extract from purple sweet potato has potential to be used as natural colorant in ice pops.

Keywords

• Purple sweet potato
• Anthocyanins
• Extraction
• Natural colorants