ORANGE JUICE QUALITY AFTER TREATMENT BY THERMAL PASTEURIZATION OR ISOSTATIC HIGH-PRESSURE

Valencia orange juice was treated by traditional thermal pasteurizatio n, high pressure processing, and a combination of the two prior to sto rage at 4 and 8 degrees C. The flavor of pressure treated juice (witho ut additional hear) stored at 4 degrees C up to 16 wk or 8 degrees C u p to 4 wk was significantly (alpha = 0.05) closer to that of fresh/fro zen juice than any of the thermal treatments. Juice microflora was red uced to below detectable limits; however pectinmethylesterase retained substantial activity in pressure treated juices. There was little eff ect on other juice quality parameters.