Effects of Exogenous Calcium Salt Treatments on Inhibiting Irradiation-Induced Softening in Diced Roma Tomatoes


  • This work was supported by United States Dept. of Agriculture, Cooperative State Research Education and Extension Service, grant nr 9902774. We wish to thank Dr. Denise Foley for her technical assistance, as well as Ready Pac Produce for the tomatoes and IBA/ Guardion for the irradiation processing. All judges were informed about the treatment procedures that the diced tomatoes underwent, and consent was obtained during initial sensory screening.


ABSTRACT: Freshly diced tomatoes were dipped into either 0.2% or 1% calcium chloride or 2% calcium lactate solution and exposed to γ-irradiation at 1.25 kGy. With increasing levels of calcium, firmness was enhanced, water-soluble pectin was decreased, and oxalate-soluble pectin was increased. Irradiation decreased instrumental firmness in all samples; however, the 1% calcium chloride and 2% calcium lactate-dipped samples remained firmer than the water-dipped control. Irradiation alone did not have a significant impact on pectic substances. Trained sensory panelists did not detect a significant loss of firmness due to irradiation in the calcified tomatoes, but some judges detected a change in flavor following the calcium dips.