High Pressure-Assisted Infusion of Calcium into Baby Carrots Part I: Influence of Process Variables on Calcium Infusion and Hardness of the Baby Carrots

This research was aimed at exploring and evaluating high pressure processing (HPP) as a technique for calcium infusion into baby carrots. HPP was employed in infusing calcium in pectin methylesterase (PME) pre-treated baby carrots using infusate solution of calcium lactate gluconate (CLG). Experiments were performed following a Box-Behnken design to evaluate the effects of pressure, holding time, and CLG concentration on the extent of calcium infusion (amount infused per serving size (85 g) of baby carrots) and the hardness of baby carrots using single pressure cycle. In addition, the effect of pressure cycling on the extent of calcium infusion was also studied by varying the number of high pressure cycles at 1, 3, and 5 at a fixed pressure (550 MPa) for a total holding time of 15 min and using 9% (w/v) CLG solution. HPP enhanced the infusion of calcium from 19.5 mg/serving in raw baby carrots to 134 mg/serving at 350 MPa–10 min–9% CLG, which was more than 3 times the amount of calcium infused in osmotically and vacuum infused controls. Pressure level, time, and CLG concentration had significant effects on calcium infusion. Increasing the number of pressure cycles increased the amount of calcium infused. The calcium infused baby carrots had higher hardness than raw unprocessed carrots.