Effects of a Combined Process of High‐Pressure Carbon Dioxide and High Hydrostatic Pressure on the Quality of Carrot Juice

TLDR

The study examined a combined high‑pressure CO₂ and hydrostatic pressure treatment to improve the safety and shelf life of carrot juice. The combined HPCD/HHP treatment completely inactivated aerobes at 4.90 MPa HPCD + 300 MPa HHP, effectively inactivated enzymes at 4.90 MPa HPCD + 600 MPa HHP with residual activities below 11.3 %, 8.8 %, and 35.1 % for polyphenoloxidase, lipoxygenase, and pectinmethylesterase, respectively, while cloud and color were mainly affected by HPCD and correlated with pH changes driven by CO₂ pressure.

Abstract

ABSTRACT: A combined treatment of high‐pressure carbon dioxide (HPCD) and high hydrostatic pressure (HHP) was investigated as a non‐thermal processing technique to enhance the safety and shelf life of carrot juice. Aerobes were completely inactivated by a combined treatment of 4.90 MPa‐HPCD and 300 MPa‐HHP. A combined treatment of 4.90 MPa‐HPCD and 600 MPa‐HHP effectively inactivated enzymes. The residual activities of polyphenoloxidase, lipoxygenase, and pectinmethylesterase were less than 11.3%, 8.8%, and 35.1%, respectively. Cloud and color were considerably affected by HPCD, but not by HHP. Enzyme activities and the total color difference showed a strong correlation with pH, which was dependent on the pressure of carbon dioxide.