Canning of Yams: Absorption and Removal of Sulfur Dioxide During Processing

Abstract

Habanero yams (D. rotundata) chunks were dipped in 4,000 p/m sulfur dioxide solutions at different pH levels for various periods of time. The absorption and removal of sulfur dioxide was determined at different canning processing steps. Sulfur dioxide absorption tended to increase as dipping time increased. Higher absorptions were obtained in samples dipped in solutions of pH 3.0. Nevertheless, sulfur dioxide content after heating in water at 200° F for 10 min was reduced, in all cases, to just 1.61 p/m. Brine pH, acidity and turbidity, and color and acidity of yam chunks were measured 15 days after being processed. The average brine pH and turbidity were 5.51 and 35.75 respectively. Acidity was higher in yam chunks than in brine. Lightness in color of canned yam chunks after being boiled in water for 10 min was less than that of yams taken fresh from the can.