High-pressure processing (HPP) can inactivate pathogenic microorganisms and degradative enzymes without the use of heat, thereby minimizing the destruction of flavors, nutrients, and other quality attributes. Lipoxygenase plays a role in the off-flavor production of tomatoes, whereas pectinesterase and polygalacturonase impact tomato texture. The purpose of this study was to determine HPP's abi...

Although the pectin content of tomatoes is relatively low in comparison with other fruits (Money & Christian, 1950), the activity of pectinesterase (pectin pectyl-hydrolase, EC 3.1.1.11) is particularly high (Kertesz, 1938). Softening of the fruit takes place relatively rapidly during ripening (Hobson, 1959), and the classical mechanism by which the effect is usually explained assumes the solub...

The cell wall-degrading enzymes polygalacturonase and pectate lyase have been suggested to be crucial for penetration and colonization of plant tissues by some fungal pathogens. We have found that Aspergillus nidulans (= Emericella nidulans), a saprophytic Ascomycete, produces levels of these enzymes equal to those produced by soft-rotting Erwinia species. Induction of polygacturonase and pecta...

polygalacturonase production under different shear stress environments by aspergillus sp. was studied. it was found that the rate of enzyme production in the stirred tank fermentor decreased with increasing the stirrer speed in the range 300-750 rpm. on the other hand, in a split cylinder air-lift fermentor, the rate of polygalacturonase production slightly increased with increasing in air rate...

Polygalacturonase-inhibiting proteins (PGIPs) are plant proteins that counteract fungal polygalacturonases, which are important virulence factors. Like many other plant defense proteins, PGIPs are encoded by gene families, but the roles of individual genes in these families are poorly understood. Here, we show that in Arabidopsis, two tandemly duplicated PGIP genes are upregulated coordinately ...

We report here the low-resolution structure of the complex formed by the endo-polygalacturonase from Fusarium phyllophilum and one of the polygalacturonase-inhibiting protein from Phaseolus vulgaris after chemical cross-linking as determined by small-angle x-ray scattering analysis. The inhibitor engages its concave surface of the leucine-rich repeat domain with the enzyme. Both sides of the en...

Plant peels could be a potential source of novel pectinases for use in various industrial applications due to their broad substrate specificity with high stability under extreme conditions. Therefore, the extraction conditions of a novel pectinase enzyme from pitaya peel was optimized in this study. The effect of extraction variables, namely buffer to sample ratio (2:1 to 8:1, X₁), extraction t...