Changes in β-carotene bioaccessibility and concentration during processing of carrot puree

The effect of some process and product factors (addition of olive oil, high pressure homogenisation, subsequent thermal or high pressure pasteurisation) on beta-carotene bioaccessibility and isomerisation of carrot puree was investigated. High pressure homogenisation could improve beta-carotene bioaccessibility by disrupting cells, but only at a pressure higher than 50 MPa. Softening of the cell walls during a subsequent thermal pasteurisation resulted in a further increase in beta-carotene bioaccessibility. Unfortunately, the high temperature also induced formation of some undesirable cis-isomers. As cell walls are probably strengthened by high pressure, high pressure pasteurisation could not positively affect the amount of bio-accessible beta-carotene. Moreover, the high pressure process induced beta-carotene oxidation. A positive effect of olive oil on beta-carotene bioaccessibility could only be noticed in combination with a thermal pasteurisation process when beta-carotene was solubilised in the oil droplets. Under high pressure however, oil can be crystallised which hinders the solubilisation of beta-carotene. (C) 2012 Elsevier Ltd. All rights reserved.