Integrated process for obtaining anthocyanins rich-extract by ultrasound-assisted extraction and starch recovery from purple yam (Dioscorea alata): a techno-economic evaluation

Purple yam (Dioscorea alata) is a tuber crop found in tropical countries and a potential valuable source of anthocyanins and starch. This study aimed to investigate the economics of an integrated process of ultrasound-assisted extraction (UAE) of anthocyanin-rich extract from purple yam and starch recovery from the extraction residue to valorizing this crop. A techno-economic evaluation was performed, which involved simulating a process plant with a capacity of 600 kg h−1 and a process that was divided into three stages: cleaning and rasping, anthocyanin extraction and, starch recovery and washing. The cleaning and rasping stage was the section that more contributed the most to the COM (49.8%). The results indicated that as yam production requires high labor, the purchasing cost of purple yam contributed highly to the cost of manufacturing (COM). When the purple yam purchasing was US$0.8 kg−1, the COM was US$15.49 kg−1 and US$14.45 kg−1 for the anthocyanin-rich extract and starch, respectively. The selling price for the anthocyanin-rich extract compensated for the high COM of the starch. The integrated process was economically feasible when the selling price of the anthocyanin-rich extract was above US$22 kg−1, and the selling price of the starch was US$0.72 kg−1.