CELL-WALL CHARACTERISTICS AND FIRMNESS OF FRESH PACK CUCUMBER PICKLES AFFECTED BY PASTEURIZATION AND CALCIUM-CHLORIDE

Changes in cell wall pectic substances, degree of pectin methylation, bound Ca++, neutral sugar composition, and firmness were determined in mesocarp tissue of pasteurized and nonpasteurized fresh pack cucumber pickles. Large changes in solubility characteristics of pectic substances occurred in cell walls of nonpasteurized pickles that were attenuated by pasteurization. In particular, water and alkali soluble pectins declined, and nonextractable pectins increased during the first month of storage. The major changes in pectic substance solubility appeared to be related to reductions in the degree of pectin methylation with a minor influence of CaCl2. Galactose in cell walls of nonpasteurized pickles was substantially reduced, and the reduction in galactose was hindered by CaCl2 or pasteurization. The amount of bound Ca++ appeared to be associated with tissue firmness after one month in storage, since firmer tissue had more cell wall bound Ca++. While firmness was associated with the amount of bound Ca++, the amount of bound Ca++ was dependent on the supply of Ca++ and the degree of pectin methylation. Copyright © 1990, Wiley Blackwell. All rights reserved