The study aimed to evaluate the effects of process parameters (time and raw material weight (RMW)) of conventional (boiling for 10–45 min) and microwave-assisted (2–8 min) aqueous extraction on the color quality (i.e., lightness (L*), chroma (C*), and hue (H°) of anthocyanin –based colorants of red and Inubi sweet potato (Ipomoea batatas L.) leaves. Using response surface methodology, it was found that RMW and boiling time (BT) and microwave time (MT) generally had a significant (p < 0.05) effect on the color quality of the extract from both extraction methods. The effects were found to vary depending on the extraction method and variety of the leaves used. Both extraction methods produced a brown to brick-red extract from the Inubi variety that turned red-violet to pink when acidified. The red sweet potato leaves produced a deep violet colored extract that also turned red-violet when acidified. It is recommended that the anthocyanin content of the extracts be measured to validate the impact of the methods on the active agent. Nevertheless, the outcomes in this study may serve as baseline data for further studies on the potential of sweet potato leaf colorants (SPLC) as a colorant with functional properties.
Sonication Effect on Modified Ultrasound Assisted Aqueous Extraction (UAAE) of Rice Bran Oil Yield
