Improved Firmness in Calcified Diced Tomatoes by Temperature Activation of Pectin Methylesterase

ther stimulated when C ther stimulated when C ther stimulated when C ther stimulated when CaCl 2 2 2 2 2 (up to 2.0% w/v) was added. (up to 2.0% w/v) was added. (up to 2.0% w/v) was added. (up to 2.0% w/v) was added. (up to 2.0% w/v) was added. When applied to half-inch diced tomato per When applied to half-inch diced tomato per When applied to half-inch diced tomato per When applied to half-inch diced tomato per When applied to half-inch diced tomato pericarp, the same conditions that led to the activation of PME also improved firmness. Diced tomatoes treated for 5 min the same conditions that led to the activation of PME also improved firmness. Diced tomatoes treated for 5 min the same conditions that led to the activation of PME also improved firmness. Diced tomatoes treated for 5 min the same conditions that led to the activation of PME also improved firmness. Diced tomatoes treated for 5 min the same conditions that led to the activation of PME also improved firmness. Diced tomatoes treated for 5 min with 0.5% CaCl with 0.5% CaCl with 0.5% CaCl with 0.5% CaCl with 0.5% CaCl 2 at 70 °C were 2.5 times firmer than diced tomatoes treated with CaCl at 70 °C were 2.5 times firmer than diced tomatoes treated with CaCl at 70 °C were 2.5 times firmer than diced tomatoes treated with CaCl at 70 °C were 2.5 times firmer than diced tomatoes treated with CaCl at 70 °C were 2.5 times firmer than diced tomatoes treated with CaCl 2 at room temperature. This at room temperature. This at room temperature. This at room temperature. This at room temperature. This improvement in texture by treating with CaCl improvement in texture by treating with CaCl improvement in texture by treating with CaCl improvement in texture by treating with CaCl improvement in texture by treating with CaCl 2 at elevated temperatures was only apparent when the tomatoes at elevated temperatures was only apparent when the tomatoes at elevated temperatures was only apparent when the tomatoes at elevated temperatures was only apparent when the tomatoes at elevated temperatures was only apparent when the tomatoes received a subsequent 100 °C treatment. Heating tomatoes to 70 °C either before or after the CaCl received a subsequent 100 °C treatment. Heating tomatoes to 70 °C either before or after the CaCl received a subsequent 100 °C treatment. Heating tomatoes to 70 °C either before or after the CaCl received a subsequent 100 °C treatment. Heating tomatoes to 70 °C either before or after the CaCl received a subsequent 100 °C treatment. Heating tomatoes to 70 °C either before or after the CaCl 2 treatment also treatment also treatment also treatment also treatment also improved firmness through a subsequent high-temperature treatment, but to a lesser extent than heating during improved firmness through a subsequent high-temperature treatment, but to a lesser extent than heating during improved firmness through a subsequent high-temperature treatment, but to a lesser extent than heating during improved firmness through a subsequent high-temperature treatment, but to a lesser extent than heating during improved firmness through a subsequent high-temperature treatment, but to a lesser extent than heating during the CaCl the CaCl the CaCl the CaCl the CaCl 2 treatment. These results are consistent with the model that heating to 70 °C greatly increases PME treatment. These results are consistent with the model that heating to 70 °C greatly increases PME treatment. These results are consistent with the model that heating to 70 °C greatly increases PME treatment. These results are consistent with the model that heating to 70 °C greatly increases PME treatment. These results are consistent with the model that heating to 70 °C greatly increases PME activity activity activity activity activity, leading to extensiv , leading to extensiv , leading to extensiv , leading to extensiv , leading to extensive pectin de-ester e pectin de-ester e pectin de-ester e pectin de-ester e pectin de-esterification and incr ification and incr ification and incr ification and incr ification and increased calcium cr eased calcium cr eased calcium cr eased calcium cr eased calcium cross-linking of the pectins in the oss-linking of the pectins in the oss-linking of the pectins in the oss-linking of the pectins in the oss-linking of the pectins in the middle lamella. Production of thermally processed diced tomatoes with improved firmness should be possible by middle lamella. Production of thermally processed diced tomatoes with improved firmness should be possible by middle lamella. Production of thermally processed diced tomatoes with improved firmness should be possible by middle lamella. Production of thermally processed diced tomatoes with improved firmness should be possible by middle lamella. Production of thermally processed diced tomatoes with improved firmness should be possible by increasing the temperature during and after calcium treatment. increasing the temperature during and after calcium treatment. increasing the temperature during and after calcium treatment. increasing the temperature during and after calcium treatment.