Variables affecting sugar removal in freeze-leached potato strips

Strips cut from cold storage (5 C), potatoes were immersed in difluorodichloromethane (R-12) from 5 to 13 sec. This rapid freezing was found to selectively damage only the frozen cells and to increase their permeability with respect to intracellular soluble materials. Subsequent immersion in water (17 to 52 C) leached the soluble materials from the frozen cells. This method of leaching in 20 min removed less than 15% of the starch released by potato strips leached at 65 C for 15 min (simulated commercial conditions). The depth of freeze determined by physical methods and by analysis of the leached surface layers showed reducing sugar removal 0.1 to 0.2 mm below the calculated average depth of freeze. In experimental lots the weight of leached materials increased with increased freezing time. Manipulating freezing depth and leaching time made it possible to achieve the required sugar removal from different lots of tubers.