Ascorbic Acid Content, pH, and Acceptability of Tomatoes Processed by Different Home Canning Methods

Each of six cultivars of tomatoes was hot packed and processed in one-pint glass jars by four home canning methods: 5 minutes at 10 pounds pressure, 10 minutes in a 100°C water bath (control), 35 minutes in a boiling water bath, and 10 minutes in a boiling water bath after addition of ¼ teaspoon citric acid per pint. The raw tomatoes ranged in pH from 4.11 to 4.71. The shape, texture, flavor, and jar fill of tomatoes processed by the pressure method were judged unacceptable by a sensory panel. Tomatoes processed 35 minutes in a boiling water bath were less acceptable than the 10-minute control. Acidified tomatoes were as acceptable as the 10-minute control in all respects except flavor, which was considered too sour at a pH of approximately 4.05. Ascorbic acid content of the acidified tomatoes was significantly lower than that of tomatoes processed with no acid added.