As a nonthermal process, ultrasonic extraction was optimized to obtain 13.21 mg/g of highly bioactive but extremely heat-sensitive cyanidin-3-O-galactoside (C3G) from Aronia melanocarpa Elliot under the following conditions; 75 kHz input frequency, 18.8 °C for the temperature, and 6.0 h process time. This yield was higher than 10.01 mg/g from a conventional juice extraction and was also higher than those from other reported sources. This concentration was proved to be very close to the predicted value of 13.70 mg/g from the quadratic model, with a regression coefficient of 0.969. This model also showed highly significant effects from changing frequency and time, and less significant effects from changing temperature. The extract from the optimized process showed 89.5% of higher DPPH radical scavenging activity than 71.3% from the conventional process. It was also found that the antioxidant activity of the extract was higher than that of using 13 µg/mL of C3G alone, possibly due to the synergistic effects of C3G with the other bioactive substances in the extract. Therefore, this optimized nonthermal process will be applied to obtain fairly high amounts of a thermally unstable and expensive C3G with fewer purification steps.

It was first confirmed that the increase of anti-inflammatory activities of Aronia melanocarpa from high-pressure homogenization at 25,000 psi and 25°C was caused by the three times higher extraction of very heat-labile cyanidin-3-O-galactoside (C3G), a bioactive anthocyanin existing in A. melanocarpa, than that of conventional 70% ethanol extraction at 80°C. The extracts from this process showed better efficacies in suppressing the production of both nitric oxide and the cytokines, IL-6 and TNF-α, and resulted in high liver weight gain in mice. This result could be employed to extract other heat-sensitive components from various bioresources.