Journal of food science vol:69 issue:5 pages:E205-E211
Carrots (Daucus carota) pretreated under different high-pressure conditions were thermally processed at temperatures in the range of 90 degreesC to 110 degreesC. Texture degradation (hardness) was monitored objectively using a texture analyzer. For a given thermal treatment, the rate constant (k-value) decreased with increasing pretreatment pressure. A high-pressure pretreatment (200 to 500 MPa) at 60 degreesC for 15 min resulted in a more pronounced texture improvement compared with the same pretreatment at 20 degreesC and 40 degreesC, respectively. Calcium impregnation conferred more beneficial effects when applied immediately after the high-pressure pretreatment. The observed changes in texture characteristics were associated with the degree of methylation of carrot pectins, which is dependent on pectinmethylesterase (PME) activity.