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...

BACKGROUND AND AIMS The hypothesis was tested that pectin content and methylation degree participate in regulation of cell wall mechanical properties and in this way may affect tissue growth and freezing resistance over the course of plant cold acclimation and de-acclimation. METHODS Experiments were carried on the leaves of two double-haploid lines of winter oil-seed rape (Brassica napus sub...

The transfer of a methyl group from S-adenosyl-L-methionine onto the carboxyl group of alpha-1,4-linked-galactosyluronic acid residues in the pectic polysaccharide homogalacturonan (HGA) is catalyzed by an enzyme commonly referred to as pectin methyltransferase. A pectin methyltransferase from microsomal membranes of tobacco (Nicotiana tabacum) was previously characterized (F. Goubet, L.N. Coun...

Studies on the rate and extent of galacturonic acid and isolated pectin digestion were carried out with nine strains of rumen bacteria (Butyrivibrio fibrisolvens H10b and D16f, Bacteroides ruminicola 23 and D31d, Lachnospira multiparus D15d, Peptostreptococcus sp. D43e, B. succinogenes A3c, Ruminococcus flavefaciens B34b, and R. albus 7). Only three strains, 23, D16f, and D31d, utilized galactu...

Two experiments with growing pigs were conducted to determine the effects of dietary P and Ca level, phytase supplementation, and ileal pectin infusion on ileal and fecal P and Ca balance, chemical composition of fecal mixed bacterial mass (MBM), and bacterial metabolic activity. Pigs (initial BW = 30 kg) were fitted with simple T-cannulas at the distal ileum. They were fed a low-P corn-soybean...

Pectin from passion fruit peels was extracted using citric acid extraction. The effects of citric acid concentration from 0.05 to 0.21 % (wt/wt), extraction time from 30 to 120 minutes and extraction temperatures from 35 to 85 ̊C on pectin yield and the degree of esterification (DE) were investigated. Using the central composite design (CCD), the optimized pectin yield was 6.44 % and degree of ...

Low-temperature blanching of sweetpotatoes (SP) prior to cooking has been shown to significantly increase firmness retention. This research investigated the effect of blanching on firmness, pectin methylesterase activity (PME), pectin methylation, and galacturonic acid and cell wall material concentrations in SP tissue subjected to blanching and cooking treatments. PME activity decreased 82% af...

This study has the following aims: (1) to confirm a methodology for a fecal indocyanine green (ICG) imaging test for measuring gastro-intestinal transit time (GITT); and (2) to compare GITT in mice given a liquid diet in which viscosity increases under acidic conditions to that in mice given stable liquid diets with comparable viscosity or regular chow. To address Aim 1, mice received ICG orall...

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we ...

It has been shown in an earlier communication (11) that auxin increases the amount of incorporation of carbon-14 derived from methyl labeled methionine into a fraction of the cell wall of Avena coleoptile sections which possesses the properties classically associated with pectin. Incorporation into this material represents but a small part of the total, the main part being into the protopectin ...