PECTIC SUBSTANCES AND FIRMNESS OF CUCUMBER PICKLES AS INFLUENCED BY CACL₂, NACL AND BRINE STORAGE

Abstract

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.

Fresh-cut cantaloupe: effects of CaCl2 dips and heat treatments on firmness and metabolic activity

“…Calcium dips have been used as firming agents to extend postharvest shelf life in apples (Abbott et al, 1989;Lurie and Klein, 1992;Mir et al, 1993;Sams et al, 1993), strawberries (García et al, 1996), sliced pears and sliced strawberries (Rosen and Kader, 1989) and zucchini slices (Izumi and Watada, 1995); and to improve postprocessing quality in blueberries (Camire et al, 1994), peaches (Postlmayr et al, 1956), fermented cucumbers (Hudson and Buescher, 1985), tomatoes (Floros et al, 1992), and sliced strawberries (Main et al, 1986). Heat treatments are another postharvest treatment that has been used to control postharvest decay and/or improve the storage quality of intact apples Lurie, 1990, 1992) and to improve post-processing quality of potatoes (Aguilar et al, 1997).…”

Factors Affecting the Softening of Pickled Pasteurised Cucumbers

“…The tissue hardening was evident also in the case of CaCl 2 treatment of fresh cucumbers infected by mould. In the cited articles (Hudson & Buescher 1985;McFeeters & Fleming 1989, 1990, 1991) the inhibitory effect of calcium on cucumber softening is explained mainly as hardening of tissues by linking of pectines. But the inhibition of enzymes by forming bigger molecules which cannot reach the active sites of the enzymes is also obvious.…”

“…Fleming et al 1987). The firmness effect of calcium depends on the degree of pectin methylation and amount of calcium added (Hudson & Buescher 1986;Howard & Buescher 1990;Krall & McFeeters 1998), the hardening effect of calcium surprisingly increases with pH reduction, below pH 5 the relative effectiveness of calcium in reducing rate of softening increases as pH decreased (Hudson & Buescher 1985;McFeeters & Fleming 1989, 1990, 1991.…”

Application of response surface methodology in optimization of lactic acid fermentation of radish: effect of addition of salt, additives and growth stimulators

“…Salt has historically been used for directing the fermentation of cucumber, radish and carrot (Hudson and Buescher 1985;Fleming et al 1987). Many ingredients apart from salt can be used in the preparation of lactic acid fermented fruits and vegetables.…”