Comparison of three extraction methods for anthocyanins from perilla frutescens leaves

The effects of three extraction methods on the yields, physicochemical properties, stabilities and antioxidant activities of anthocyanins from perilla frutescens (L.) Britt. were investigated and compared. Three extraction methods were applied to extract perilla leaves anthocyanins (PLAs), which include ultrasonic-assisted water extraction (UWE), ultrasonic-assisted ethanol extraction (UEE) and ultrasonic-assisted aqueous two-phase extraction (UATPE). The yields, color quality, stabilities and antioxidant activities of three anthocyanins were significantly different. More specifically, UATPE-PLAs had the maximum total anthocyanins content (18.37 ± 0.91 mg/g) and the best color valence (30.01 ± 0.08). After storage at 4 °C for 15 days, the retention rate of the UATPE-PLAs (95.52 ± 1.29%) was higher than UEE-PLAs (89.73 ± 1.34%) and UWE-PLAs (62.22 ± 3.85%). And the UATPE-PLAs were stable at pH 3.7, while the UWE-PLAs and the UEE-PLAs were stable at pH 2.5. What's more, UATPE-PLAs displayed higher DPPH radical scavenging (98.21 ± 0.04%), reduction power (IC50 = 0.58 mg Trolox equivalent/mL), hydroxyl radical scavenging ability (89.45 ± 0.01%) and anti-lipid peroxidation ability (87.72 ± 0.03%).