Abstract: The effects of ultra-high pressure processing (UHPP) (200－600 MPa for 10 min) on physicochemical properties, nutritional quality and antioxidant activity of fresh-squeezed coconut juice were studied. The results showed that, compared to the control, UHPP did not significantly change the contents of soluble solid content, total sugar, total acid and total phenol and pH in coconut juice (P ＞ 0.05). The contnent of free amino acids increased significantly after 500 or 600 MPa processing (P ＜ 0.05). The content of vitamin C reduced significantly, with a retention rate of 87.9%－97.6% after UHPP treatment. The antioxidant activity decreased significantly after 400 MPa processing, but increased after 600 MPa processing (P ＜ 0.05). Sensory evaluation showed no difference between UHPP treated coconut milk and the control. In summary, UHPP can effectively protect the natural flavor and and nutritional components of fresh-squeezed coconut juice.

Key words: ultra-high pressure processing, coconut juice, quality, antioxidant activity