Extraction of red pigment from Chinese jujube peel and the antioxidant activity of the pigment extracts

Abstract Chinese jujube is a delicious fruit with high antioxidant nutrients. The peel, however, always discarded due to its indigestibility. In the current study, peels were collected for red pigment extraction. Six extraction-related parameters (ethanol concentration, solid-liquid ratio, material granularity, enzyme enzymolysis time, and pH) optimized peel extraction using Plackett–Burman Box–Behnken designs. When treated 1.18% cellulase 73% ethanol at pH 3.15, optimization enhanced efficiency by 29.7% compared control. Ultra-high performance liquid chromatography (UHPLC) assay revealed that delphinidin 3- O -galactoside cyanidin -rutinoside chloride major components of extracts. Additionally, extracts exhibited free radical scavenging capacity strong Fe 3+ reducing power. Finally, it also provides us simple new method efficient natural antioxidants from peels.