Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PECTINS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,783 records · Page 99Linked to original sources

Enzymatic properties of two catalytic modules of Clostridium stercorarium pectate lyase Pel9A.

Clostridium stercorarium F-9 pectate lyase Pel9A is a modular enzyme composed of two hypothetical family-9 catalytic modules of the polysaccharide lyases, CM9-1 and CM9-2, in order from the N terminus. In this study, we constructed and characterized CM9-1 and CM9-2 polypeptides as rCM9-1 and rCM9-2 respectively. Both of them, like the full-length Pel9A, required the Ca2+ ion for their enzyme activities and showed high activity toward polygalacturonic acid but lower activity toward pectin. The specific activity of rCM9-2 was three times higher than that of rCM9-1 and rCM9-2 by itself efficiently catalyzed the depolymerization reaction of polygalacturonic acid into monosaccharide as the major product. It was found that rCM9-1 and rCM9-2 adsorbed to polygalacturonic acid and pectin on native affinity PAGE analysis, suggesting that they contain an independent carbohydrate-binding module separable from a catalytic module or consist of a catalytic module with a binding affinity for pectic substrates.

Calcium↗

Luminal glucagon-like peptide-1(7-36) amide-releasing factors in the isolated vascularly perfused rat colon.

Glucagon-like peptide-1 (GLP-1) is released from endocrine cells of the distal part of the gut after ingestion of a meal. GLP-1 secretion is, in part, under the control of hormonal and/or neural mechanisms. However, stimulation of the colonic L cells may also occur directly by the luminal contents. This was examined in the present study, using an isolated vascularly perfused rat colon. GLP-1 immunoreactivity was measured in the portal effluent after luminal infusion of a variety of compounds which are found in colonic contents (nutrients, fibers, bile acids, short-chain fatty acids (SCFAs)). Oleic acid (100 mM) or a mixture of amino acids (total concentration 250 mM), or starch (0.5%, w/v) did not increase GLP-1 secretion over basal value. A pharmacological concentration of glucose (250 mM) elicited a marked release of GLP-1 which was maximal at the end of infusion (400% of basal), while 5 mM glucose was without effect on secretion. Pectin evoked a dose-dependent release of GLP-1 over the range 0.1-0.5% (w/v) with a maximal response at 360% of basal when 0.5% pectin was infused. Cellulose or gum arabic (0.5%) did not modify GLP-1 secretion. The SCFAs acetate, propionate or butyrate (5, 20 and 100 mM) did not induce a significant release of GLP-1. Among the four bile acids tested, namely taurocholate, cholate, deoxycholate and hyodeoxycholate, the last one was the most potent at eliciting a GLP-1 response with a maximal release at 300% and 400% of the basal value when 2 and 20 mM bile acid were administered respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Controlled release of protein from hydrocolloid gel microbeads before and after drying.

Casein entrapped within gel microbeads using alginate, amidated LM pectin, gellan gum and a system containing a mixture of these polysaccharides (pectin:gellan:alginate, 1/3: 1/3: 1/3), were obtained by ionic gelation in a high-pressure capillary apparatus. Hydrogenated vegetable fat was also added to produce the gel microbeads and protein release in all the systems was measured, including from freeze-dried capsules containing protein and fat. Encapsulation efficiency, capsule size and morphology were evaluated as well as the protein release profile. Encapsulation efficiencies from 83.7 to 90.7% were obtained for the protein capsules and from 71.8 to 95.4% for those containing protein and fat. Greater release was observed from gel microbeads without fat where alginate presented the greatest diffusion (100%) and the system with a mixture of polyssacharides, the best barrier, with protein retention of 90% after 240 min in solution. The fat containing gel microbeads presented good percent retentions and both the gel microbeads and the dry microbeads showed similar percentages for release. The majority of the systems studied showed a burst effect on release. Gel microbeads size distribution was similar, both with and without fat, and independent of the matrix material, the mean size being 150microm. The morphological observations showed that the gel microbeads were spheroidal with a homogenous distribution of fat droplets in the microcapsules. Agglomeration occurred on drying but many particles maintained a partially spheroidal form, with a configuration of solid material.

Alginates↗

Nutrient digestion by ileal cannulated dogs as affected by dietary fibers with various fermentation characteristics.

We studied the effects of dietary fibers with various fermentation characteristics on nutrient digestion at the distal ileum and in the total tract of dogs. The following high-protein (34%), high-fat (23%) diets were fed: 1) a control treatment (CON) with 0% supplemental fiber; 2) beet pulp (BP), 7.5%; 3) low-cellulose mixture (LCM), 2.5% cellulose + 5.0% pectin; 4) high-cellulose mixture (HCM), 5.0% cellulose + 2.5% pectin; or 5) Solka Floc (SF), 7.5% cellulose. Nutrient intakes by fiber-supplemented dogs were similar among treatment groups but greater (P < .05) than for dogs fed the control diet. Digestion of nutrients at the distal ileum was similar among groups except for fat: the dogs fed BP digested less fat than those fed the other sources of dietary fiber. Digestion of amino acids at the distal ileum was similar for all groups, except for lysine, which increased (P < .05) in digestibility as dietary cellulose concentration increased. Dogs consuming LCM had lower apparent ileal digestibility values for all nutrients, including most amino acids, than dogs consuming HCM or SF. Total tract digestion of DM and OM by dogs fed supplemental fiber was less (P < .05) than for dogs fed the control diet. The BP treatment was higher than other fiber treatments in total tract digestion of OM (P < .10) and total dietary fiber (P < .05). Total tract digestibilities of all nutrients exhibited either linear or quadratic responses to dietary cellulose concentrations. Apparent ileal and total tract nutrient digestion was influenced by the source of dietary fiber consumed.

Amino Acids↗

Fruit and vegetable fiber fermentation by gut microflora from canines.

The objective of this study was to assess fermentability by canine gut microflora to include shortchain fatty acid (SCFA) production, organic matter (OM) disappearance, and gas production of vegetable and fruit fiber sources compared to fiber standards (psyllium, citrus pectin, and Solka Floc). Fiber sources included apple pomace, carrot pomace, flaxseed, fruit blend (mixture of peach, almond, nectarine, and plum), grape pomace, pea hulls, pistachio, and tomato pomace. Substrates were fermented in vitro for 4, 12, and 24 h with fecal flora obtained from three healthy dogs. Citrus pectin had the highest OM disappearance, SCFA production, and gas production at all times of fermentation; psyllium was intermediate and Solka Floc was lowest. A wide variation in fermentability was noted among the vegetable and fruit fiber sources. Apple pomace, carrot pomace, and flaxseed had the greatest fermentability as assessed by OM disappearance. Pea hulls and tomato pomace had intermediate OM disappearances, and fruit blend, grape pomace, and pistachio were poorly fermented. Carrot pomace produced the largest amounts of gas and SCFA. Apple pomace produced high concentrations of gas but intermediate concentrations of SCFA. Pea hulls and tomato pomace produced intermediate concentrations of gas and SCFA, whereas flaxseed, fruit blend, grape pomace, and pistachio produced low amounts of these fermentation products. For all substrates collectively, OM disappearance was highly correlated with both gas production (r2 = 0.782 and 0.723 for 12- and 24-h values, respectively) and SCFA production (r2 = 0.737 and 0.738 for 12- and 24-h values, respectively). In general, OM disappearance, gas production, and SCFA production were related to the insoluble:soluble fiber ratio in the samples; as the insoluble:soluble ratio decreased (increased soluble fiber), the OM disappearance, gas production, and SCFA production increased.

Animal Feed↗

The effect of feeding different protein-free diets on the recovery and amino acid composition of endogenous protein collected from the distal ileum and feces in pigs.

Nine barrows with an average initial weight of 60 kg were fitted with simple T-cannulas at the distal ileum. The animals were fed four different protein-free diets according to an incomplete latin square design. Diet 1 (control diet) consisted of 79.7% cornstarch, 10% sucrose, 3% Alphafloc (a source of cellulose), 3% canola oil and a vitamin-mineral premix. Diets 2, 3 and 4 contained, respectively, 4% pectin, an additional 7% cellulose and an additional 10% canola oil, each included at the expense of cornstarch. Feces were collected during 3 d following a 7-d adaptation period. Thereafter, digesta were collected during two 24-h periods with a 24-interval between periods. The pigs were fed 800 g of feed twice at 0800 and 2000. Added pectin increased (P less than .05) the recovery of endogenous protein in ileal digesta from 19.8 diet (diet 1) to 24.0 g per kg dry matter intake. This increment was largely due to increases (P less than .05) in glycine and proline from 1.9 to 2.4 and from 6.2 to 8.4 g per kg dry matter intake, respectively. In feces, only added cellulose increased (P less than .05) excretion of endogenous protein (8.4 vs 11.1 g/kg DM intake) and of most amino acids. Including additional fat did not affect the quantity of endogenous protein and amino acids recovered in ileal digesta or feces. Small but significant differences (P less than .05) were observed in the amino acid composition of endogenous protein recovered in ileal digesta when the different protein-free diets were fed.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

In vivo studies with fibre components.

There are few studies in man examining the in vivo effects of dietary fibre on bile acid metabolism but divergent results have been recorded depending on the amount and type of fibre eaten. Studies in which the fibre components pectin, cellulose, and lignin were fed to normal volunteers for four weeks have been reported. The highly fermentable component pectin is associated with increased secondary bile acid formation in contrast to the partially fermentable component cellulose in which the opposite occurs. Lignin has no effect on bile acid metabolism. No component significantly alters biliary lipids. Since ordinary diets contain a mixture of different fibres the net effect will depend on the relative amounts of each. Significant changes in bile acid metabolism and biliary lipids in the longer term (greater than 4 weeks) however, are not precluded by the results of these short term studies.

Bile Acids and Salts↗

Coating alginate beads with cross-linked biopolymers: a novel method based on a transacylation reaction.

Stable membranes were formed around alginate beads using a transacylation reaction between polysaccharidic esters, namely propylene glycol alginate (PGA) or pectin, and various proteins (human serum albumin (HSA), ovalbumin, bovine hemoglobin, lactoserum proteins). In a standard procedure, two reagents (PGA or pectin+protein) were added to a Na-alginate solution: beads were formed by dropwise addition into a calcium solution. Then the transacylation reaction was started by alkalinization of the bead suspension. A membrane was formed around the beads, made of a protein directly bound to a polysaccharide through amide linkages. The thickness of the membranes and the lysis time in trypsin were increased by raising the amount of NaOH used for the transacylation step. In a modified procedure, coated beads were obtained, incorporating PGA in the initial Na-alginate solution, and HSA in the transacylation bath. Activated charcoal was encapsulated in HSA-PGA beads, giving particles with adsorption properties towards creatinine. Assays were performed using PGA associated with alkaline phosphatase as the membrane-forming protein. Stable beads were obtained having a relative activity of 39.3%, as compared with free enzyme.

Acylation↗

The rachitogenic effects of fractions of rye and certain polysaccharides.

When fed to chicks rye is rachitogenic as well as growth depressing. The component or components of rye that cause these effects have not been identified. In an attempt to separate the factors, a water extract of rye was fractionated by precipitation with ethanol or ammonium sulfate. The precipitated fractions were fed to chicks. Although there were different responses to growth and bone ash from the ethanol fractions, they were not statistically significant. In another experiment, guar gum, pectin, or gum arabic was fed to chicks as 2% of the diet. Guar gum was both growth depressing and rachitogenic, pectin was only growth depressing, and gum arabic was without effect.

Animals↗

Preventive effect of a pectic polysaccharide of the common cranberry Vaccinium oxycoccos L. on acetic acid-induced colitis in mice.

AIM: To study isolation and chemical characterization of pectin derived from the common cranberry Vaccinium oxycoccos L. (oxycoccusan OP) and the testing of its preventive effect on experimental colitis. METHODS: Mice were administrated orally with OP two days prior to a rectal injection of 5% acetic acid and examined for colonic damage 24 h later. Colonic inflammation was characterized by macroscopical injury and enhanced levels of myeloperoxidase activity measured spectrophotometrically with o-phenylene diamine as the substrate. The mucus contents of the colon were determined by the Alcian blue dye binding method. Vascular permeability was estimated using 4% Evans blue passage after i.p. injection of 0.05 mol/L acetic acid. RESULTS: In the mice treated with OP, colonic macroscopic scores (1.1+/-0.4 vs 2.7, P<0.01) and the total square area of damage (10+/-2 vs 21+/-7, P<0.01) were significantly reduced when compared with the vehicle-treated colitis group. OP was shown to decrease the tissue myeloperoxidase activity in colons (42+/-11 vs 112+/-40, P<0.01) and enhance the amount of mucus of colitis mice (0.9+/-0.1 vs 0.4+/-0.1, P<0.01). The level of colonic malondialdehyde was noted to decrease in OP-pretreated mice (3.6+/-0.7 vs 5.1+/-0.8, P<0.01). OP was found to decrease the inflammatory status of mice as was determined by reduction of vascular permeability (161+/-34 vs 241+/-21, P<0.01). Adhesion of peritoneal neutrophils and macrophages was also shown to decrease after administration of OP (141+/-50 vs 235+/-37, P<0.05). CONCLUSION: Thus, a preventive effect of pectin from the common cranberry, namely oxycoccusan OP, on acetic acid-induced colitis in mice was detected. A reduction of neutrophil infiltration and antioxidant action may be implicated in the protective effect of oxycoccusan.

Acetic Acid↗

[Enterosorption by nonstarch polysaccharides as a method of treatment of children with mercury poisoning].

Possibility of apple pectin "Classic AU-701" (E-440) usage as the means of detoxication was evaluated in 146 children of 7-14 years old with the increased content of mercury in urine. Under the influence of enterosorption the mercury withdrawal with urine increased, the period of mercury intoxication was shortened by 6 weeks, the hemogram and vegetative regulation indices of the affected children improved. The authors consider pectin to be effective in mercury intoxication treatment. It may be also used to increase intoxication resistance under exposure to chemicals.

Adaptation, Physiological↗

[Antisteatotic effects of four kinds of dietary fibers in rats fed on high cholesterol diet: a preliminary morphometric analysis].

The hypolipidaemic and antisteatotic effects of the Konnyaku Powder (KP) have been reported before. In order to evaluate further the antisteatotic role played by KP, the effects of KP on the levels of liver lipid and on the hepatic histopathology and morphometry in comparison with those of pectin, algin and agar were studied. Sixty Wistar strain rats were divided into 6 groups: a normal diet group, a high cholesterol diet group (HC), and 4 test groups, in which the animals were fed on a diet similar to that of the high cholesterol diet group with addition of KP, pectin, algin or agar at a dosage of 5%, respectively. All the animals were killed at the end of the diet treatment for 9 weeks. The results showed that relative liver weights were lower in four experimental groups than in the HC group. The levels of total and free cholesterol, and triglyceride in the liver were lower in KP group than in HC group and in the other three experimental groups. Hepatic histopathology and morphometric examination indicated that antisteatotic effects of KP appeared to be much more significant than those of the other fibers.

Agar↗

Expression of UDP-glucose dehydrogenase reduces cell-wall polysaccharide concentration and increases xylose content in alfalfa stems.

The primary cell-wall matrix of most higher plants is composed of large amounts of uronic acids, primarily D-galacturonic acid residues in the backbone of pectic polysaccharides. Uridine diphosphate (UDP)-glucose dehydrogenase is a key enzyme in the biosynthesis of uronic acids. We produced transgenic alfalfa (Medicago sativa) plants expressing a soybean UDP-glucose dehydrogenase cDNA under the control of two promoters active in alfalfa vascular tissues. In initial greenhouse experiments, enzyme activity in transgenic lines was up to seven-fold greater than in nontransformed control plants; however, field-grown transgenic plants had only a maximum of 1.9-fold more activity than the control. Cell-wall polysaccharide content was lower and Klason lignin content was higher in transgenics compared to the nontransformed control. No significant increase in pectin or uronic acids in the polysaccharide fraction was observed in any line. Xylose increased 15% in most transgenic lines and mannose concentration decreased slightly in all lines. Because of the complexity of pectic polysaccharides and sugar biosynthesis, it may be necessary to manipulate multiple steps in carbohydrate metabolism to alter the pectin content of alfalfa.

Biomass↗

[Genetic regulation of pathogenicity and virulence factors in bacteria Erwinia carotovora subsp. atroseptica: phenotypic characteristic of bacteria with the mutant kduD gene].

In contrast to the closely related bacteria Erwinia chrysanthemi, bacteria Erwinia carotovora subsp. atroseptica produce lower levels of main pathogenicity and virulence factors (pectate lyases, cellulases, and proteases) in the presence of pectins. This effect was shown to be connected with the accumulation of the intermediate product of intracellular degradation of these substances, 2,5-diketo-3-deoxygluconate (DK2). The presence of DK2 in the culture broth of mutant bacteria, connected to its export in the environment, was established. The production of pectate lyases, cellulases, and proteases is repressed by DK2 only at its high concentrations in the cultivation medium, whereas low concentrations of DK2 induce the production of virulence factors. Genes involved in the intracellular catabolism of pectin substances and induced by both low and high DK2 concentrations in the cultivation medium are not repressed by this metabolite.

Cellulase↗

[Low-residue diets supplemented with fermentable fiber. Effect on experimental colonic anastomosis].

Presentation of an experimental study comparing the scarring of colic anastomoses performed in Wistar rats fed with three different types of diet: a standard laboratory diet, an enteral low-residue diet and a low-residue diet supplemented with fermentable fibre in short chain fatty acids (pectin). Scarring in the group fed with the standard laboratory diet showed greater anastomotic complications, and the microscopic appearance was more inflamed. The administration of low-residue diets reduced the level of complications, but also reduced the concentration of collagen and the parietal rupture tension. The addition of pectin to a low-residue diet maintained the complications at a low level, and also significantly increased the pressure parameters and the collagen concentration.

Anastomosis, Surgical↗

[Ecologic features of cultures of the species Clostridium gürfelii].

The Clostridium cultures decomposing pectin were isolated from flax straw during flax retting. The activity was manifested only at high pH values, the optimum pH being 6.7--8.2. Such ecological adaptation of the cultures is determined by the properties of the pectolytic enzyme complex which they synthesize. The complex does not contained polygalacturonase (the optimum pH 5.0) but has a high activity of pectate transeliminase (the optimum pH 8.0--8.4). The cultures differ from Clostridium felsineum which possesses a high activity of polygalacturonase and therefore can decompose pectin in acid medium. By their morphological, cultural and physiological properties, the bacteria are classed as Clostridium güfelii (Prévot, 1966).

Carboxylic Ester Hydrolases↗

[Characterization of the biomass of the stems of sweet sorghum].

In this study the amount of glucose, sucrose and fructose was determined in the water soluble fraction while cellulose, hemicellulose, pectin and lignin contents were determined in the alcohol insoluble fraction after hydrolysis. Stalks of sweet sorghum (Sorghum vulgare L., var. saccharatum) cv. Vespa, Soave, Roce and MN 1500 at the physiological ripeness stage were used. The results of the analysis of variance with the least significant difference method (LSD, = 0.05) show that cv. Vespa and Roce have a significantly higher total amount of glucose, fructose and sucrose and at the same time, a lower cellulose, pectin, hemicellulose and lignin content then cv. Soave and cv. MN 1500.

Carbohydrates↗

A tube assay for contamination caused by pectolytic aspergilli.

Spoilage fungi of the genus Aspergillus were detected and estimated in 24 h by a modification of the Most Probable Number method. The method is based on the production of pectolytic enzymes in a medium supplemented with pectin. These enzymes hydrolyse the bonds of pectin to produce galacturonic acid, causing a fall in pH and an indicator present in the medium changes colour, thus allowing tubes to be scored as positive. Results obtained by this method were generally higher than those obtained by traditional plate counts.

Aspergillus↗