The effects of brine treatments (CaCl2 and NaCl) and storage on pectic substances and texture of cucumber pickles were examined. Firmness of cucumber pickles was closely associated with the solubility characteristics and degree of esterification (DE) of pectic substances. Brining, storage, time of CaCl2 addition and concentration of NaCl and CaCl2 were all observed to influence the characteristics of pectic substances. Important to preventing softening was maintenance of pectic substances not extractable (NXP) by conventional methods, i.e., by water (WSP), the chelator sodium hex‐ametaphosphate (CSP), and dilute alkali (OHSP). Erosion of NXP consistently resulted in increased levels of CSP and reduced firmness. Reducing the amount of demethylation of pectins was also associated with maintaining firmness. Although the DE declined rapidly during brining, tissues from treatments that enhanced firmness had pectic substances with the highest DE. CaCl2 added to brine at the beginning of fermentation was most effective in preventing the demethylation of pectins and solubilization of NXP. In contrast, delayed addition of CaCl2 and storage in low NaCl concentration (5% or less) caused greater pectin demethylation, erosion of NXP with concomitant increases in CSP and tissue softening.

Cucumbers were fermented and held for 30 days in equilibrated solutions containing low NaCl (11-13" salometer) and high NaCl (18.5-20.5" salometer) with and without CaCl, and/or polygalacturonase (PG). CaCl, and PG treatments did not interfere with fermentation. Separately, CaCl, enhanced firmness of pickles while PG was effective in causing excessive softening. When CaCl, was present in PG containing solutions, softening by PG was inhibited.

The relationship between pectin methylation and tissue firmness was examined in cucumber pickles exposed to pre-brining and brining treatments. Tissue treated with CaCI, prior to or during brining, blanched before brining or held at 2°C during brine storage resisted softening. Although all treatments reduced the degree of esterification (DE) of pectic substances, less demethylation occurred in treatments that protected against softening. Join point regression analysis of the data indicated that maximum firmness of mesocarp tissue was attained when the DE of pectins was 12.3 2 1.2 or greater. Firmness declined concomitantly when the DE declined below 12.3 2 1.2. Methods that protect against excessive demethylation of pectins appear to be important in retarding softening of cucumber pickle tissue during storage in brine.

The effects of brining, fermentation, storage, time of CaCI, addition and concentration of NaCl and CaC12 on Ca' + , Mg' +, Na+, and K+ bound to middle lamella-cell wall material of cucumber pickle mesocarp tissue were examined. Changes in the amount of each bound cation occurred rapidly during the first 2 days of brining; levels then remained relatively stable during fermentation and storage if concentrations of NaCl or CaClz in brines were not altered. NaCl reduced levels of bound Ca+ +, Mg+ +, and K+, and the presence of CaC12 increased the amount of bound Ca+ + by displacing the other cations. Delayed addition of CaCI, to brines enhanced the content of bound Ca+ +, indicating that levels of bound Ca++ may not be related to maintenance of firmness.