POTASSIUM HYDROXIDE REPLACEMENT FOR LYE (SODIUM HYDROXIDE) IN TOMATO PEELING

Abstract

Lye (sodium hydroxide [NaOH]) peeling is the most common method for peeling tomatoes in the Midwest U.S. With the rise in the cost of NaOH and the associated disposal problems, alternative methods for peeling need to be examined. Solutions of NaOH, potassium hydoxide (KOH) and calcium hydroxide (Ca[OH] 2 ) at different concentrations were compared to determine their efficacy as peeling agents. Ca(OH) 2 was ineffective as a peeling agent because of its low solubility. KOH produced peeling equivalent to NaOH, but at half the normality. A lower normality is needed because of the increased reactivity of KOH compared to NaOH. This is further demonstrated by the addition of salts to the solution. The use of KOH instead of NaOH may result in cost savings and decreased waste disposal problems.