A continuous high-pressure carbon dioxide system for cloud and quality retention in orange juice

Abstract

Orange juice (OJ) was treated with a continuous high-pressure carbon dioxide (HPCD) system, and the quality parameters pH, Brix, titratable acidity (TA), cloud, pectinesterase (PE) activity, color, and sensory attributes were determined. Treatment pressures were 38, 72, and 107 MPa, and CO2/juice (w/w) ratios were from 0.40 to 1.18. Residence time was kept at 10 min. Cloud increased between 446% and 846% after treatments. There were no significant changes in pH and Brix (α=0.05). TA of the treated juice was found to be significantly different fromthat of control (α=0.01). PE was not completely inactivated. There was a small, but significant increase in juice L-value (α = 0.01) and a decrease in a-value for color. There was no significant change in b-values (α = 0.05). Statistical analysis for the sensory data showed no difference between fresh, frozen control juice and treated juice after 2 wk of refrigerated storage at 1.7 ◦C.