Anthocyanins characterization and antioxidant activities of sugarcane (Saccharum officinarum L.) rind extracts

Anthocyanins in rind extracts of three sugarcane cultivars, ROC 22, Haitang 22 and Guitang 21, were characterized using ultra performance liquid chromatography (UPLC) combined with electrospray ionization quadrupole-time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS). A total of thirteen anthocyanins were identified and quantified. Except for cyanidin-3-glucoside, twelve anthocyanins were reported for the first time from sugarcane. The total anthocyanin content (TAC) varied significantly from 10.8 (Haitang 22) to 132.0 μg/g dry rind weight (DW) (ROC 22). Regarding single anthocyanins, ROC 22 contained 79.8 μg/g DW cyanidin-3-glucoside but this anthocyanin was not identified in the other two cultivars. Instead, Guitang 21 contained 94.6 μg/g DW malvidin-3-p-coumaroyl-rhamnoside-5-glucoside. The rinds of red sugarcane cultivars ROC 22 and Guitang 21 had higher total antioxidant activities than green sugarcane Haitang 22, which was attributed to much higher contents of free and total phenolics. This study provides useful information for the production of valuable nutraceuticals from sugarcane.