Abstract:Camellia oleifera seed-cake（COS）is a by-product made during Camellia oleifera seed oil production process. COS contains about 10%-20% plant protein and a variety of essential amino acids，which is a potential resource for quality plant protein. To improve the utilization effectiveness and reduce resource waste during local extraction，ultrasonic-assisted enzymatic extraction（UAEE）was applied for Camellia oleifera seed-cake crude protein（COCP）. The antioxidant activity and lipid-lowing ability of COCP were then explored. The optimal extraction process was secured through the single factor test. The results showed that the optimal conditions of UAEE for COCP were as follows: amylase and cellulase addition of 2.5% and 0.9%，enzymolysis time of 150 min，enzymolysis temperature of 50 ℃，enzymolysis pH of 4.5，the 70% ethanol，the liquid ratio of 1∶40 （g/mL）. 350 W power was used for 60 min ultrasonic treatment to 100 g enzyme solution，and after acid precipitation and desiccation，the COCP recovery rate can reach up to（83.3 ± 0.6）%，0.54 times higher than that of the group without UAEE. It was found that the scavenging efficiencies of the 50 mg/mL extract obtained by this method were 66.5%，70.7%，and 67.9% for clearance of hydroxyl radical（·OH），DPPH radical，and ABTS＋radical. It had a certain adsorption effect on cholate，and its inhibition rate for pancreatic lipase was dose-dependent. At 1.0 mg/mL，the inhibition rate reached（49.5±0.5）%. The results indicated that COCP had certain antioxidant properties and lipid-lowering ability in vitro.