The Relationship of Visual Maturity Indicators to Tomato pH

Abstract The pH of tomatoes influences the heat treatment required for a safe canning process. Tomato maturity, one of the many factors that influence pH, is often estimated from the skin color. A significant relationship between pH and maturity (as indicated by a visual color classification) was found for three of four red tomato cultivars examined, however, the skin color of any individual tomato was not a good predictor for pH. Titratable acidity decreased with increasing maturity, but for two of the four cultivars there was no increase in soluble solids on ripening.