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1.
Food Chem ; 302: 125343, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31430630

RESUMO

Pectin was extracted from blueberry powder as water soluble fraction (WSF), rich in branched regions, and chelator soluble fraction (CSF), linear, with strong negative charge. Binding of pectins with three anthocyanin standards (malvidin-3-glucoside; M3G, cyanidin-3-glucoside; C3G, and delphinidin-3-glucoside; D3G) and blueberry extract (BBE) were used. Without blueberry pectin, M3G was the most stable followed by C3G, whereas D3G completely disappeared after gastrointestinal digestion. CSF prevented M3G and C3G degradation more than WSF, the in vitro stability was highest with CSF and C3G. Increased stability of anthocyanins after simulated gastrointestinal digestion suggests that anthocyanins can be transported to colon where gut microbiota actively produce anthocyanin metabolites. The amount of bound anthocyanins that interacted with blueberry pectin increased as the number of hydroxyl groups increased on anthocyanins. Hydrogen bonding in addition to electrostatic interaction contribute to stability of pectin-anthocyanins interaction at pH 4.0 and contribute to stability under gastrointestinal simulation.


Assuntos
Antocianinas/química , Antocianinas/farmacocinética , Mirtilos Azuis (Planta)/química , Pectinas/química , Antocianinas/metabolismo , Digestão , Glucosídeos/química , Glucosídeos/metabolismo , Glucosídeos/farmacocinética , Ligações de Hidrogênio , Concentração de Íons de Hidrogênio , Pectinas/metabolismo , Pectinas/farmacocinética , Extratos Vegetais/química , Eletricidade Estática
2.
J Sci Food Agric ; 99(13): 5720-5733, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31152455

RESUMO

BACKGROUND: Dietary strategies such as the inclusion of prebiotics have been suggested for modulating intestinal microbiota. In piglets, this strategy could result in a reduction of post-weaning-associated disorders and the use of antibiotics. To date, mainly purified fractions have been tested for their prebiotic effects at weaning while trials of potential health-promoting effects of products and corresponding by-products remain rare. In this study, fructan- and pectin-based ingredients have been tested in a two-step in vitro model for their fermentation kinetics as well as for their short-chain fatty acid production and microbiota profiles in fermentation broth as indicators for their prebiotic activity. RESULTS: Chicory root, in contrast to chicory pulp, exhibited an extensive and rapid fermentation similar to inulin and oligofructose, although butyrate levels of root and pulp did not reach those of the purified fractions. Chicory pulp showed higher relative levels of Lactobacillus spp., Bifidobacterium spp., Clostridium cluster IV and butyryl-CoA:acetate-CoA transferase gene abundance compared to chicory root. Sugar beet pulp, orange and citrus by-products displayed extensive gas fermentation patterns, equivalent to those of purified pectin, and revealed an elevated butyrate production compared to purified pectin. Moreover, several orange and citrus by-products displayed significantly higher relative levels of Bifidobacterium spp. in comparison to purified pectin. CONCLUSIONS: Chicory root and pulp as well as orange and citrus by-products appear to be promising ingredients for piglet diets for modulating intestinal fermentation for health purposes. © 2019 Society of Chemical Industry.


Assuntos
Ração Animal/análise , Bactérias/metabolismo , Fezes/microbiologia , Frutanos/metabolismo , Microbioma Gastrointestinal , Pectinas/metabolismo , Resíduos/análise , Ração Animal/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ácidos Graxos Voláteis/metabolismo , Fermentação , Frutanos/análise , Intestinos/microbiologia , Cinética , Pectinas/análise , Suínos
3.
J Agric Food Chem ; 67(27): 7755-7764, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31251611

RESUMO

Pectic polysaccharides from New Zealand (NZ) spinach (Tetragonia tetragonioides) and karaka berries (Corynocarpus laevigatus) were extracted and analyzed. NZ spinach polysaccharides comprised mostly homogalacturonan (64.4%) and rhamnogalacturonan I (5.8%), with side chains of arabinan (8.1%), galactan (2.2%), and type II arabinogalactan (7.1%); karaka berry polysaccharides comprised homogalacturonan (21.8%) and rhamnogalacturonan I (10.0%), with greater proportions of side chains (arabinan, 15.6%; galactan, 23.8%; and type II arabinogalactan, 19.3%). Screening of gut commensal Bacteroides showed that six were able to grow on the NZ spinach extract, while five were able to grow on the karaka berry extract. Analysis of the polysaccharides remaining after fermentation, by size-exclusion chromatography and constituent sugar analysis, showed that the Bacteroides species that grew on these two substrates showed preferences for the different pectic polysaccharide types. Our data suggest that, to completely degrade and utilize the complex pectin structures found in plants, members of Bacteroides and other bowel bacteria work as metabolic consortia.


Assuntos
Aizoaceae/química , Bacteroides/crescimento & desenvolvimento , Magnoliopsida/química , Pectinas/metabolismo , Polissacarídeos/metabolismo , Bacteroides/metabolismo , Fermentação , Frutas/química , Microbioma Gastrointestinal/fisiologia , Nova Zelândia , Pectinas/análise , Pectinas/química , Folhas de Planta/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação
4.
Plant Sci ; 285: 141-150, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203879

RESUMO

Plant tissue brittleness is related to cellular structure and lodging. MED0031 is a mutant identified previously from ethyl methane sulfonate treatment of diploid wheat accession TA2726, showing brittleness in both stem and leaf. In microscopic and histological observations, the mutant was found to have less large vascular bundles per unit area, a thinner sclerenchyma cell wall, and a broader parenchyma, compared with the wild type. The mutated gene, TmBr1, was mapped to a 0.056 cM interval on chromosome 5Am. This gene was cloned using a MapRseq approach that searched the candidate gene through combination of the prior target gene mapping information with SNP calling and discovery of differentially expressed genes from RNA_seq data of the wild type and a BC3F2 bulk showing the mutant phenotype. TmBr1 encodes a COBL protein and a nonsense mutation within the region coding for the conserved COBRA domain caused premature translation termination. Introduction of TmBr1 to Arabidopsis AtCOBL4 mutant rescued the phenotype, demonstrating their functional conservation. Apart from the effect on cellulose content, the TmBr1 mutation might modulate synthesis of noncellulosic polysaccharide pectin as well. Application of the MapRseq approach to isolation of genes present in recombination cold spots and complicated genomes was discussed.


Assuntos
Clonagem Molecular/métodos , Genes de Plantas/genética , Triticum/genética , Parede Celular/metabolismo , Celulose/metabolismo , Mapeamento Cromossômico , Genes de Plantas/fisiologia , Lignina/metabolismo , Microscopia Eletrônica de Varredura , Pectinas/metabolismo , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Triticum/anatomia & histologia , Triticum/fisiologia
5.
J Food Sci ; 84(7): 1776-1783, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31218715

RESUMO

Citrus pectin hydrolysates (Citrus paradisi [Mafc.]) from "Foster," "Red Shambar," "Tangelo Orlando," and "Citrumelo Swingle" cultivars were obtained by partial chemical hydrolysis and their properties as culture media (sole carbon/nutrient source) and encapsulating agents of Lactobacillus plantarum CIDCA 83114 were evaluated. The concentration of neutral sugars was maximal after 2-hour hydrolysis. All hydrolysates were rich in glucose >xylose >galactose >galacturonic acid >mannose >arabinose. "Citrumelo Swingle" cultivar was the one with the highest concentration of xylose. After 24 hr of fermentation with L. plantarum CIDCA 83114, bacterial viability increased from 6.76 ± 0.14 to almost 9 log CFU/mL, and lactic acid concentration, from 2.63 ± 0.41 to 7.82 ± 0.15 mmol/L in all hydrolysates. Afterwards, bacteria were entrapped in pectate-calcium beads by ionotropic gelation. Bacterial viability did not significantly decrease after freeze-drying and storage the beads at 4 °C for 45 days. PRACTICAL APPLICATION: Pectin hydrolysates were adequate culture media for microorganisms, as determined by the viabililty and lactic acid production. Considering that citrus peels are agro-wastes obtained in large quantities, their use as encapsulating materials provides a solution to overcome the environmental problem they entail.


Assuntos
Citrus paradisi/química , Meios de Cultura/metabolismo , Lactobacillus plantarum/química , Pectinas/química , Citrus paradisi/metabolismo , Meios de Cultura/química , Fermentação , Liofilização , Hidrólise , Ácido Láctico/análise , Ácido Láctico/metabolismo , Lactobacillus plantarum/classificação , Lactobacillus plantarum/crescimento & desenvolvimento , Lactobacillus plantarum/metabolismo , Pectinas/metabolismo , Açúcares/análise , Açúcares/metabolismo
6.
J Sci Food Agric ; 99(13): 5792-5798, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31162672

RESUMO

BACKGROUND: Recently, a producer of fermented ciders observed 'vinyl' off-odors formed during fermentation of pear juice previously depectinized at ≥ 49 °C but not if depectinized at lower temperatures. The objective of this study was to investigate the source of this spoilage and evaluate factors that affect formation. RESULTS: Analysis of untainted and tainted samples obtained from the producer determined the causative agent to be indole, a compound sometimes produced by yeast (Saccharomyces cerevisiae) during fermentation. To mimic commercial depectinization conditions, pectinases were added to pear juices held at 35 °C for 45 min (Treatment A), 49 °C for 45 min (Treatment B), or 49 °C for 90 min (Treatment C). Juice processing conditions did not affect yeast growth nor progress of alcoholic fermentation. Although neither yeast strain (DV10 or MERIT) synthesized indole during fermentation of Treatment A juices, the compound was produced by MERIT in Treatments B (27.05 µg L-1 ) and C (469.9 µg L-1 ). Supplementation of Treatment C juice with pyridoxine (vitamin B6 ) prior to fermentation resulted in no detectable indole formed. However, juices from Treatments A, B, or C contained similar concentrations of pyridoxine and non-detectable amounts of tryptophan, a potential precursor to indole. Furthermore, indole was not detected during fermentations of a synthetic pear juice medium without pyridoxine. CONCLUSION: Supplementation of cider musts with pyridoxine prior to fermentation and choice of yeast strain can lower the risk of formation of off-odors caused by indole. However, other unidentified factors are present which affect its formation in perry. © 2019 Society of Chemical Industry.


Assuntos
Bebidas Alcoólicas/análise , Etanol/metabolismo , Manipulação de Alimentos/métodos , Indóis/metabolismo , Pectinas/metabolismo , Pyrus/química , Saccharomyces cerevisiae/metabolismo , Bebidas Alcoólicas/microbiologia , Etanol/análise , Fermentação , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Indóis/análise , Malus/química , Malus/microbiologia , Odorantes/análise , Poligalacturonase/química , Pyrus/microbiologia
7.
Food Chem ; 292: 188-196, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31054664

RESUMO

Soy protein isolate (SPI) and sugar beet pectin (SBP) were adopted to fabricate double network (DN) gels via thermal treatment and laccase-catalysis. The concentrations of SBP (0.5%-2.5%, w/w) and SPI (4%-8%, w/w) were evaluated. DN gels showed higher holding water capacity (WHC, above 83%), compared with SBP single gel (75.96%). The presence of SPI improved the mechanical properties of gels significantly. Apparent phase separation could be observed when SPI concentration was 4%. Moreover, interpenetrating networks gradually formed with the increase of SPI concentration. The favorable structural heterogeneity and mechanical integrity derived from these polymers might be mainly responsible for the enhancement of the mechanical properties. The presence of SBP and laccase could improve the ß-sheet amounts of SPI and make it form more rigid structure according to the results of circular dichroism (CD) and fluorescence spectra. The excellent performance of DN gels could enable the delivery of various components.


Assuntos
Géis/química , Lacase/metabolismo , Pectinas/química , Proteínas de Soja/química , Beta vulgaris/metabolismo , Biocatálise , Dicroísmo Circular , Emulsões/química , Pectinas/metabolismo , Conformação Proteica em Folha beta , Reologia , Proteínas de Soja/metabolismo , Temperatura Ambiente , Água/química
8.
BMC Plant Biol ; 19(1): 215, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31122198

RESUMO

BACKGROUND: Sugarcane is a tropical crop that can accumulate high concentration of sucrose in the stem as a storage carbohydrate. For that reason, sugarcane accounts for approximately 75% of all the sugar produced in the world and has become the main sugar source to produce first-generation bioethanol in Brazil. Daily rhythms cause plants to adapt and coordinate their metabolism to achieve maximum photosynthesis and carbohydrate production throughout the day. Circadian rhythms arise from the interaction of an internal oscillator and external stimuli, whereas diel rhythms occur in response to a light-dark cycle. Diel signalling contributes to synchronizing circadian rhythms to photoperiods, and levels of carbohydrates oscillate in a diel fashion. Under regular photoperiods, they are synthesized during the daytime and consumed throughout the night as an energy reserve. However, short days can induce higher rates of synthesis during daytime and lower rates of consumption in the dark. Cell wall carbohydrates are also diurnally regulated, and it has been shown that celluloses, hemicelluloses and pectin are deposited/degraded at different times of the day. To assess the diel carbohydrate profile in young sugarcane plants, we measured soluble sugars and cell wall components along a time course in plants subjected either to a regular day or short day. RESULTS: Short-day influenced sucrose synthesis and cell wall components. In short-day a 44% increase in sucrose concentration was detected in the dark, but was stable during the day. Cellulose, hemicellulose and pectin also fluctuate within a 24 h interval when subjected to a short day. A 38% increase in leaf sheath cellulose was observed from the middle of the day to the first hour of the night. Leaf sheath pectin and hemicellulose also increased from the day to the night, while it decreased in leaves. CONCLUSIONS: The presented data show diurnal patterns of soluble sugar metabolism together with temporal regulation of cell wall metabolism for a short day, suggesting that diel signalling has a role in how sugarcane manages sugar accumulation and partitioning. Understanding cell wall synthesis/degradation dynamics may help to improve the yield of sugarcane.


Assuntos
Parede Celular/metabolismo , Ritmo Circadiano/fisiologia , Fotoperíodo , Saccharum/fisiologia , Açúcares/metabolismo , Pectinas/metabolismo , Polissacarídeos/metabolismo
9.
Plant Sci ; 283: 329-342, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128704

RESUMO

Cold is an abiotic stress seriously threatening crop productivity by decreasing biomass production. The pollen tube is a target of cold stress, but also a useful model to address questions on cell wall biosynthesis. We here provide (immuno)cytological data relative to the impact of cold on the pollen tube cell wall. We clearly show that the growth pattern is severely affected by the stress, since the typical pulsed-growth mechanism accompanied by the periodic deposition of pectin rings is absent/severely reduced. Additionally, pectins and cellulose accumulate in bulges provoked by the stress, while callose, which colocalizes with pectins in the periodic rings formed during pulsed growth, accumulates randomly in the stressed samples. The altered distribution of the cell wall components is accompanied by differences in the localization of glucan synthases: cellulose synthase shows a more diffuse localization, while callose synthase shows a more frequent cytoplasmic accumulation, thereby denoting a failure in plasma membrane insertion. The cell wall observations are complemented by the analysis of intracellular Ca2+, pH and reactive oxygen species (ROS): while in the case of pH no major differences are observed, a less focused Ca2+ and ROS gradients are present in the stressed samples. The standard oscillatory growth of pollen tubes is recovered by transient changes of turgor pressure induced by hypoosmotic media. Overall our data contribute to the understanding of the impact that cold stress has on the normal development of the pollen tube and unveil the cell wall-related aberrant features accompanying the observed alterations.


Assuntos
Parede Celular/metabolismo , Tubo Polínico/crescimento & desenvolvimento , Tabaco/genética , Cálcio/metabolismo , Parede Celular/fisiologia , Celulose/metabolismo , Resposta ao Choque Frio , Técnica Indireta de Fluorescência para Anticorpo , Germinação , Glucanos/metabolismo , Concentração de Íons de Hidrogênio , Pressão Osmótica , Pectinas/metabolismo , Pólen/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tabaco/metabolismo
10.
World J Microbiol Biotechnol ; 35(6): 84, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31134444

RESUMO

Pectin is a type of complex hydrophilic polysaccharide widely distributed in plant resources. Thermal stable pectinase has its advantage in bioapplication in the fields of food processing, brewing, and papermaking, etc. In this study, we enzymatically characterized a putative endo-polygalacturonase TcPG from a Talaromyces cellulolyticus, realized its high-level expression in Pichia pastoris by in vitro constructing of a series of multi-copy expression cassettes and real time quantitative PCR screening. The secretive expression level of TcPG was nonlinear correlated to the gene dosage. Recombinants with five-copy TcPG gene in the host genome showed the highest expression. After cultivation in a bioreactor for about 96 h, the enzyme activity reached 7124.8 U/mL culture. TcPG has its optimal temperature of 70 °C. Under the optimized parameters, the pectin could be efficiently hydrolyzed into oligosaccharides.


Assuntos
Dosagem de Genes , Pectinas/metabolismo , Pichia/genética , Poligalacturonase/biossíntese , Poligalacturonase/genética , Talaromyces/enzimologia , Talaromyces/genética , Reatores Biológicos , Clonagem Molecular , Regulação Fúngica da Expressão Gênica , Hidrólise , Pichia/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Proteínas Recombinantes/genética , Temperatura Ambiente , Fatores de Tempo
11.
BMC Genomics ; 20(1): 430, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138126

RESUMO

BACKGROUND: The white rot fungus Phlebia radiata, a type species of the genus Phlebia, is an efficient decomposer of plant cell wall polysaccharides, modifier of softwood and hardwood lignin, and is able to produce ethanol from various waste lignocellulose substrates. Thus, P. radiata is a promising organism for biotechnological applications aiming at sustainable utilization of plant biomass. Here we report the genome sequence of P. radiata isolate 79 originally isolated from decayed alder wood in South Finland. To better understand the evolution of wood decay mechanisms in this fungus and the Polyporales phlebioid clade, gene content and clustering of genes encoding specific carbohydrate-active enzymes (CAZymes) in seven closely related fungal species was investigated. In addition, other genes encoding proteins reflecting the fungal lifestyle including peptidases, transporters, small secreted proteins and genes involved in secondary metabolism were identified in the genome assembly of P. radiata. RESULTS: The PACBio sequenced nuclear genome of P. radiata was assembled to 93 contigs with 72X sequencing coverage and annotated, revealing a dense genome of 40.4 Mbp with approximately 14 082 predicted protein-coding genes. According to functional annotation, the genome harbors 209 glycoside hydrolase, 27 carbohydrate esterase, 8 polysaccharide lyase, and over 70 auxiliary redox enzyme-encoding genes. Comparisons with the genomes of other phlebioid fungi revealed shared and specific properties among the species with seemingly similar saprobic wood-decay lifestyles. Clustering of especially GH10 and AA9 enzyme-encoding genes according to genomic localization was discovered to be conserved among the phlebioid species. In P. radiata genome, a rich repertoire of genes involved in the production of secondary metabolites was recognized. In addition, 49 genes encoding predicted ABC proteins were identified in P. radiata genome together with 336 genes encoding peptidases, and 430 genes encoding small secreted proteins. CONCLUSIONS: The genome assembly of P. radiata contains wide array of carbohydrate polymer attacking CAZyme and oxidoreductase genes in a composition identifiable for phlebioid white rot lifestyle in wood decomposition, and may thus serve as reference for further studies. Comparative genomics also contributed to enlightening fungal decay mechanisms in conversion and cycling of recalcitrant organic carbon in the forest ecosystems.


Assuntos
Genoma Fúngico , Lignina/metabolismo , Polyporales/genética , Transportadores de Cassetes de Ligação de ATP/genética , Metabolismo dos Carboidratos , Celulose/metabolismo , Genômica , Pectinas/metabolismo , Peptídeo Hidrolases/genética , Polyporales/enzimologia , Polissacarídeos/metabolismo , Metabolismo Secundário/genética
12.
J Plant Physiol ; 238: 63-71, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31146183

RESUMO

This study aimed to investigate the firmness retention by ethylene treatment in olive fruit, as observed earlier. Ethylene concentrations up to 1000 µL L-1 were applied to dark green 'Konservolia' olives harvested shortly before the green maturation and exposed to 20 °C for up to 9 d. Surprisingly, the results indicated a tendency to fruit firmness increases in concentration-dependent manner in a non-climacteric fruit. The highest concentration increased the firmness within 12 h by approximately 1.35-fold, but transiently for approximately up to 5 d; all ethylene inhibitors tested, either of synthesis (ethoxyvinyl glycine or AVG), or perception (1 -methyl-cyclopropene or 1-MCP, and silver nitrate) prevented the firmness increase. Texture was evaluated by firmness and changes in lignin, cellulose (CL), total pectins (TPC), water soluble pectins (WSP) and total non-cellulosic sugars (total sugars) concentrations, and in pectin esterification degree (DE) in the alcohol insoluble residue (AIR) of 'Konservolia' fruit pericarp during 1.5-d, 5-d and 10-d treatments with 1000 µL L-1 ethylene at 20 °C. Pectins in AIR were also extracted sequentially with cyclohexane-trans-1,2-diaminetetra-acetate (CDTA), Na2CO3, 1 M and 4 M KOH. The results showed that on day 1.5, the increased firmness was consistent with increased CL (crystalline formation, as observed by microscopy), total sugars and DE levels, but reduced WSP, whereas softening reversed the changes and lowered TPC and CDTA-soluble pectins in all fruit on day 10. However, on day 5 ethylene-treated olives exhibited a transitional phase during softening, characterized by retention of high TPC concentration and energy demand, as indicated by elevated respiration rates. The inhibitor 1-MCP, applied before ethylene, did inhibit the responses to ethylene treatment. Ethylene firming effect and the respective cell wall changes in olives are demonstrated for first time. The experiments could be used for research on perception and transcription responses to ethylene in olive, a non-climacteric fruit. In practice, high ethylene concentrations could also be beneficial for firmness increase and/or short storage of dark green olives.


Assuntos
Parede Celular/metabolismo , Ciclopropanos/farmacologia , Etilenos/metabolismo , Frutas/metabolismo , Olea/metabolismo , Parede Celular/efeitos dos fármacos , Celulose/metabolismo , Produção Agrícola/métodos , Relação Dose-Resposta a Droga , Etilenos/antagonistas & inibidores , Etilenos/farmacologia , Qualidade dos Alimentos , Frutas/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Lignina/metabolismo , Olea/efeitos dos fármacos , Olea/crescimento & desenvolvimento , Pectinas/metabolismo
13.
Carbohydr Polym ; 217: 126-134, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079668

RESUMO

Longan pulp is an excellent source of polysaccharides and other nutrients that have many health benefits. However, longans is susceptible to pulp breakdown after harvest and loses its nutrition values. To solve this problem, this study aimed to study the effects of a novel chitosan, Kadozan, on pulp breakdown index, contents of pectin, cellulose and hemicelluloses, and activities of enzymes in longan pulp relating to disassembly of polysaccharides (XET, PE, PG, ß-Gal, and cellulase). The data illustrated that, compared to the control longans, chitosan-treated longans contained higher amounts of CWM, CSP, ISP, cellulose and hemicelluloses, but exhibited lower pulp breakdown index, lower activities of cell wall-disassembling enzymes, and contained lower WSP amount. These results suggested that Kadozan with a dilution of 1:500 (VKadozan: VKadozan + Water) could significantly decrease activities of disassembling-enzymes and depolymerization of polysaccharides in cell wall, and subsequently alleviate pulp breakdown and prolong storage-life of postharvest longans.


Assuntos
Parede Celular/efeitos dos fármacos , Quitosana/farmacologia , Inibidores Enzimáticos/farmacologia , Frutas/metabolismo , Polissacarídeos/metabolismo , Sapindaceae/metabolismo , Parede Celular/metabolismo , Celulose/metabolismo , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Glicosídeo Hidrolases/antagonistas & inibidores , Hidrólise/efeitos dos fármacos , Pectinas/metabolismo
14.
Carbohydr Polym ; 217: 90-97, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079689

RESUMO

Pectin oligosaccharides (POSs) have prebiotic and antiglycation activities in vitro, but the specific structure-activity relationship is unclear. In this study, POSs were obtained by enzymatic and ultrasound-assisted enzymatic degradation of pectin polysaccharide (PPS), respectively. Based on the chemical characterization, the antiglycation in vitro and prebiotic activities of POSs were compared and the structure-activity relationship was studied. The results showed that the antiglycation activity of POSs in vitro was proportional to the galacturonic acid content and GalA:Rha molar ratios except for the low molecular weight POSs (LM-POSs), and inversely proportional to its branching degree, such as Ara:Rha and Gal:Rha molar ratios. In addition, it was also found that the prebiotic activity of POSs was positively correlated with Ara:Rha and Gal:Rha molar ratios in molecule composition and the neutral sugar content, especially galactose and arabinose. The degree of esterification (DE) was less important for both antiglycation and prebiotic activity of POSs. These results provided an important theoretical basis for POSs application in food.


Assuntos
Actinidia/química , Frutas/química , Produtos Finais de Glicação Avançada/antagonistas & inibidores , Oligossacarídeos/metabolismo , Pectinas/metabolismo , Prebióticos , Adulto , Fezes/microbiologia , Feminino , Fermentação , Microbioma Gastrointestinal/fisiologia , Humanos , Hidrólise , Masculino , Estrutura Molecular , Peso Molecular , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Pectinas/química , Pectinas/isolamento & purificação , Poligalacturonase/química , Relação Estrutura-Atividade
15.
BMC Plant Biol ; 19(1): 151, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30999851

RESUMO

BACKGROUND: Grafting is a technique widely used in horticulture. The processes involved in grafting are diverse, and the technique is commonly employed in studies focusing on the mechanisms that regulate cell differentiation or response of plants to abiotic stress. Information on the changes in the composition of the cell wall that occur during the grafting process is scarce. Therefore, this study was carried out for analyzing the composition of the cell wall using Arabidopsis hypocotyls as an example. During the study, the formation of a layer that covers the surface of the graft union was observed. So, this study also aimed to describe the histological and cellular changes that accompany autografting of Arabidopsis hypocotyls and to perform preliminary chemical and structural analyses of extracellular material that seals the graft union. RESULTS: During grafting, polyphenolic and lipid compounds were detected, along with extracellular deposition of carbohydrate/protein material. The spatiotemporal changes observed in the structure of the extracellular material included the formation of a fibrillar network, polymerization of the fibrillar network into a membranous layer, and the presence of bead-like structures on the surface of cells in established graft union. These bead-like structures appeared either "closed" or "open". Only three cell wall epitopes, namely: LM19 (un/low-methyl-esterified homogalacturonan), JIM11, and JIM20 (extensins), were detected abundantly on the cut surfaces that made the adhesion plane, as well as in the structure that covered the graft union and in the bead-like structures, during the subsequent stages of regeneration. CONCLUSIONS: To the best of our knowledge, this is the first report on the composition and structure of the extracellular material that gets deposited on the surface of graft union during Arabidopsis grafting. The results showed that unmethyl-esterified homogalacturonan and extensins are together involved in the adhesion of scion and stock, as well as taking part in sealing the graft union. The extracellular material is of importance not only due to the potential pectin-extensin interaction but also due to its origin. The findings presented here implicate a need for studies with biochemical approach for a detailed analysis of the composition and structure of the extracellular material.


Assuntos
Arabidopsis/fisiologia , Glicoproteínas/metabolismo , Pectinas/metabolismo , Proteínas de Plantas/metabolismo , Arabidopsis/anatomia & histologia , Arabidopsis/citologia , Arabidopsis/ultraestrutura , Parede Celular/metabolismo , Epitopos/metabolismo , Esterificação , Hipocótilo/citologia , Hipocótilo/fisiologia , Hipocótilo/ultraestrutura
16.
An Acad Bras Cienc ; 91(1): e20180058, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30994757

RESUMO

Brazil is the world's largest producer of orange and passion fruit, which are destined mainly for industrialization, generating grand volumes of wastes. The solid portion of these residues is a rich source of pectin - composed mainly of galacturonic acid and neutral sugars, which through the hydrolysis process can be used in biological conversion processes, as the production of polyhydroxyalkanoates (PHAs). This way, we characterized these wastes, followed by the extraction and hydrolysis of pectin for employ as a substrate for the cell growth of Cupriavidus necator. The results confirmed the large portion of pectin (almost 40 g.100g-1) and soluble sugars, present in these wastes. The hydrolyzed extract showed as a good source of carbon for the cell growth of C. necator with YX/S 0.56 and 0.44, µMax 0.27 and 0.21 for orange and passion fruit wastes respectively, similar to other carbon sources. This way, the extraction and hydrolysis of orange and passion fruit wastes for the cellular growth of C. necator, can be a good alternative to converting of residues in high value added product.


Assuntos
Citrus sinensis/química , Citrus sinensis/microbiologia , Cupriavidus necator/fisiologia , Passiflora/química , Passiflora/microbiologia , Extratos Vegetais/química , Resíduos Sólidos , Metabolismo dos Carboidratos , Carboidratos/química , Citrus sinensis/metabolismo , Hidrólise , Passiflora/metabolismo , Pectinas/química , Pectinas/metabolismo , Extratos Vegetais/metabolismo , Poli-Hidroxialcanoatos/química , Poli-Hidroxialcanoatos/metabolismo , Valores de Referência , Ciclização de Substratos
17.
Food Chem ; 289: 40-48, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955629

RESUMO

Calcium chloride (1% w/w, CaCl2) and pectin methylesterase (PME) (15 U/mL) were vacuum impregnated (VI) into jujubes to preserve their quality. The nanostructure of jujube pectin was investigated using atomic force microscopy (AFM) to determine the degradation mechanism of pectin. CaCl2 with PME under VI treatment (VI + Ca + PME) maintained jujubes' quality. Weight loss in VI + Ca + PME group at day 56 was only 60.36% of that in control group (CK). Firmness, soluble solids content, and ascorbic acid content of jujubes in VI + Ca + PME group were higher than those in CK. Firmness was highly positively correlated with sodium carbonate-soluble pectin (SSP) content. According to AFM results, frequencies of molecules with a width ≥60 nm of water-soluble pectin (WSP), chelate-soluble pectin (CSP), and SSP were the highest in VI + Ca + PME group at the end of storage. WSP, CSP, and SSP degradation was delayed by VI + Ca + PME treatment. The quality of jujubes was effectively maintained by VI + Ca + PME treatment.


Assuntos
Cloreto de Cálcio/química , Hidrolases de Éster Carboxílico/metabolismo , Pectinas/química , Ziziphus/metabolismo , Ácido Ascórbico/análise , Quelantes/química , Frutas/metabolismo , Microscopia de Força Atômica , Nanoestruturas/química , Pectinas/metabolismo , Espectrofotometria , Vácuo , Água/química
18.
Food Chem Toxicol ; 129: 54-63, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30978372

RESUMO

In this study, a unique citrus species (Citrus australasica) was selected, and its fruit characteristics, phenolic compounds and ability to inhibit inflammation were preliminarily studied. Finger lime fruits showed distinctive features in shape, size, weight, colour, total soluble solids, water-soluble pectin, sugar and acids contents. Combining UPLC-HRMS and UPLC-DAD analysis, 31 phenolics, 1 secoiridoid derivative and 1 neolignan glycoside were preliminarily identified and quantified. The phenolics composition of finger limes showed cultivar and tissue specificity. Antioxidant evaluation showed that extracts from finger lime cultivar of 'XiangBin' exhibited better antioxidant capacities than cultivar of 'LiSiKe', especially in peel. LPS-induced NO-releasing model was performed in the mouse microglia BV-2 cell line. Results illustrated that finger limes inhibited the NO-releasing and the inflammation-related cytokines including IL-1ß, IL-6 and TNFα elevation. QRT-PCR revealed that finger lime extracts alleviated LPS-induced upregulation of iNOS, IL-6, JAK2, TNFα, TLR2, TLR4, IL-1ß, NF-κB and LPS-induced downregulation of IκBα. This study may expand our knowledge on the physiochemical characteristics and bioactive properties of citrus fruits.


Assuntos
Antioxidantes/farmacologia , Citrus/química , Óxido Nítrico/antagonistas & inibidores , Fenóis/farmacologia , Ácidos/metabolismo , Animais , Linhagem Celular , Cromatografia Líquida/métodos , Regulação para Baixo/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos , Microglia/citologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Óxido Nítrico/metabolismo , Pectinas/metabolismo , Fenóis/química , Fenóis/isolamento & purificação , Açúcares/análise , Regulação para Cima/efeitos dos fármacos
19.
Plant Sci ; 280: 367-382, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30824016

RESUMO

Brachypodium distachyon (Brachypodium) is now well considered as being a suitable plant model for studying temperate cereal crops. Its cell walls are phylogenetically intermediate between rice and poaceae, with a greater proximity to these latter. By microscopic and biochemical approaches, this work gives an overview of the temporal and spatial distribution of cell wall polysaccharides in the grain of Brachypodium from the end of the cellularization step to the maturation of grain. Variation in arabinoxylan chemical structure and distribution were demonstrated according to development and different grain tissues. In particular, the kinetic of arabinoxylan feruloylation was shown occuring later in the aleurone layers compared to storage endosperm. Mixed linked ß-glucan was detected in whole the tissues of Brachypodium grain even at late stage of development. Cellulose was found in both the storage endosperm and the outer layers. Homogalacturonan and rhamnogalacturonan I epitopes were differentially distributed within the grain tissues. LM5 galactan epitope was restricted to the aleurone layers contrary to LM6 arabinan epitope which was detected in the whole endosperm. A massive deposition of highly methylated homogalacturonans in vesicular bodies was observed underneath the cell wall of the testa t2 layer at early stage of development. At maturity, low-methylated homogalacturonans totally fulfilled the lumen of the t2 cell layer, suggesting pectin remodeling during grain development. Xyloglucans were only detected in the cuticle above the testa early in the development of the grain while feruloylated arabinoxylans were preferentially deposited into the cell wall of t1 layer. Indeed, the circumscribed distribution of some of the cell wall polysaccharides raises questions about their role in grain development and physiology.


Assuntos
Brachypodium/metabolismo , Polissacarídeos/metabolismo , Xilanos/metabolismo , Brachypodium/crescimento & desenvolvimento , Parede Celular/metabolismo , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Glucanos/metabolismo , Especificidade de Órgãos , Pectinas/metabolismo
20.
Plant Sci ; 281: 9-18, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824065

RESUMO

Arabinogalactan proteins as cell wall structural proteins are involved in fundamental processes during plant development and growth. The aim of this study was to evaluate AGP function in the distribution of pectin, cellulose and callose along Fragaria x ananassa pollen tube and to associate the cell wall structure with local mechanical properties. We used Yariv reagent which interacts with AGPs and allows the observation of the assembly of cell walls without AGPs performing their function. Cytochemical, immunofluorescence labelling and atomic force microscope have been used to characterize the changes in cell wall structure and stiffness. It was shown that disordering of the structure of AGP present in cell walls affects the localization of cellulose, pectins and the secretion of callose. Changes in cell wall assembly are relevant to pollen tube mechanical properties. The stiffness gradient lengthwise through the axis of the pollen tube has demonstrated a significantly higher Young's modulus of the shank region than the growth zone. It has been revealed that the apex of the pollen tube cultured in the presence of Yariv reagent is stiffer (1.68 MPa) than the corresponding region of the pollen tube grown under control conditions (0.13-0.27 MPa). AGP affects the structure of the cell wall by changing the distribution of other components and the modification of their localization, and hence it plays a significant role in the mechanical properties of the cell wall.


Assuntos
Parede Celular/metabolismo , Fragaria/metabolismo , Tubo Polínico/metabolismo , Celulose/metabolismo , Fragaria/crescimento & desenvolvimento , Glucanos/metabolismo , Mucoproteínas/metabolismo , Pectinas/metabolismo , Proteínas de Plantas/metabolismo , Tubo Polínico/crescimento & desenvolvimento
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