Pectinesterase Activity, Pectin Methylation, and Texture Changes During Storage of Blanched Cucumber Slices |
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| Authors: | R. F. McFEETERS H. P. FLEMING R. L THOMPSON |
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| Affiliation: | The authors are affiliated with the USDA-ARS, Food Fermentation Laboratory, and North Carolina Agricultural Research Service, Dept. of Food Science, North Carolina State Univ., Raleigh, NC 27695-7624. |
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| Abstract: | Pectin methylation in blanched cucumber slices after 6 months’storage in acid brine (pH 3.7) ranged from 9% (no blanch) to 48% (99°C, 3 min blanch). An 81°C blanch caused complete pectinesterase inactivation, but 15 - 20% reactivation occurred during storage. After a 99°C blanch, only slight reactivation was observed. Pectinesterase was not inactivated at 66°C or less, but up to 85% of the activity was lost during storage. Firmness changes were complex. A clear relationship between pectin methylation and firmness changes was not observed. A 66 or 81°C blanch resulted in best firmness retention. Calcium ion was very effective in prevention of firmness loss regardless of the extent of pectin methylation. |
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