Effect of thermal and high pressure processes on structural and health-related properties of carrots (Daucus carota)

In the present study, the effect of thermal and equivalent high pressure processes on structural (texture and microstructure) and health-related (total beta-carotene concentration, beta-carotene isomerisation and beta-carotene bio-accessibility) properties of carrots was investigated. Both a mild and strong pasteurisation process and a sterilisation process were considered. Both for pasteurisation and sterilisation, the high pressure process resulted in a similar or improved (2.6-4.5 times higher) hardness of the carrots compared to the equivalent thermal process. In contrast to the thermally treated samples, almost no beta-carotene isomerisation was observed for the high pressure processed samples. However, the effect of high pressure on beta-carotene bio-accessibility was dependent on the intensity of the process. Going from mild pasteurisation, over strong pasteurisation to sterilisation. the beta-carotene bio-accessibility of the high pressure treated samples changed from 1.2 times higher, over 1.2 times lower to 2.5 times lower than that of the thermally treated samples. (C) 2010 Elsevier Ltd. All rights reserved.