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 β-carotene concentration, β-carotene isomerisation and β-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 β-carotene isomerisation was observed for the high pressure processed samples. However, the effect of high pressure on β-carotene bio-accessibility was dependent on the intensity of the process. Going from mild pasteurisation, over strong pasteurisation to sterilisation, the β-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.