Garrote et al. (1993) surveyed the effect of NaOH concentration (4-20%), process temperature (55-95องศา) and time (1-7 min) on the yield, peeling quality, unpeeled skin and total usage of NaOH. They also evaluated titratable NaOH in the potato tissue, NaOH penetration and “heat ring” depth. The best peeling quality, maximum yield and minimum total usage of NaOH resulted with the following conditions’concentration, 11-13%; time, 5-5.70 minutes and temperature, 90-95องศา. The maximum temperature for which the “heat ring” and NaOH penetration depth were equal was 72องศา where , at 20องศา NaOH and 7 minutes, peeling quality was very good and the “heat ring” was eliminated.