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1.
Int J Biol Macromol ; 277(Pt 2): 133591, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38960233

RESUMO

Pectic polysaccharides are considered the highly complex natural plant polysaccharides which plays a vital role in plant tissue structure and human health. Detailed characterization of the monosaccharide composition can provide insights into the pectic polysaccharide structure. Nevertheless, when analyzing the monosaccharides of pectic polysaccharide, it is crucial to address the issue of incomplete hydrolysis that can occur due to the formation of acid-induced precipitates. Based on above, the main purpose of this article is to provide an optimized method for monosaccharide analysis of pectic polysaccharides through acid hydrolysis optimization using high-performance anion exchange chromatography (HPAEC) The results indicate that reducing the sample concentration to 0.5 mg/mL effectively reduces the acid gelling phenomenon and promotes the complete hydrolysis of pectin polysaccharides. The optimized parameters for acid hydrolysis involve 110 °C for 6 h in 2 M TFA. Furthermore, the consistency of this method is assessed, along with its ability to analyze pectin polysaccharides from various fruits. This hydrolysis approach holds promise for enabling accurate quantification of monosaccharide composition in pectic polysaccharides.


Assuntos
Monossacarídeos , Pectinas , Pectinas/química , Pectinas/análise , Monossacarídeos/análise , Monossacarídeos/química , Hidrólise , Cromatografia por Troca Iônica/métodos , Cromatografia Líquida de Alta Pressão/métodos , Polissacarídeos/química , Polissacarídeos/análise , Frutas/química
2.
Environ Res ; 258: 119368, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38848997

RESUMO

The most recent advancement in food packaging research involves improving the shelf life of perishable foods by utilising bio-based resources that are edible, eco-friendly, and biodegradable. The current study investigated the effect of edible pectin coating on mature green tomatoes to improve shelf life and storage properties. Zucchini pectin was used to make edible coating. The antimicrobial and antioxidant properties of extracted pectin were investigated. The findings indicated that the extracted pectin had antimicrobial (Staphylococcus aureus, Escherichia coli, and Aspergillus niger) and antioxidant (34.32% at 1 mg/mL) properties.Tomatoes were immersed in pectin solutions of varying concentrations, 1, 3, and 5% (w/v). Physiological evaluations of weight loss, total sugar content, titratable acidity pH, and ascorbic acid were performed on tomatoes during their maturing stages of mature green, light red, pure red, and breaking. Coating the tomatoes with pectin (5%) resulted in minimal weight loss while increasing the retention of total sugar, ascorbic acid, and titratable acidity. The shelf life of the pectin-coated tomatoes was extended to 11 days, while the uncoated control tomatoes lasted 9 days. Thus, a 5% edible pectin solution was found to be effective in coating tomatoes. The current study suggests that using 5% pectin as an edible coating on tomatoes can delay/slow the ripening/maturing process while also extending the shelf-life of tomatoes without affecting their physiochemical properties, which is scalable on a large scale for commercial purposes.


Assuntos
Pectinas , Solanum lycopersicum , Pectinas/análise , Pectinas/química , Solanum lycopersicum/química , Armazenamento de Alimentos , Conservação de Alimentos/métodos , Antioxidantes/análise , Antioxidantes/farmacologia , Embalagem de Alimentos , Ácido Ascórbico/análise , Anti-Infecciosos/análise , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química
3.
Food Chem ; 458: 140093, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38943960

RESUMO

This study evaluated the effects of postharvest ripening (0-6 days, D0-6) on cell wall pectin profile, infrared-assisted hot air-drying characteristics, and sugar content. Results showed that during postharvest ripening progress, the content of water-soluble pectin (WSP) and chelate-soluble pectin (CSP) increased while the content of Na2CO3-soluble pectin (NSP) and hemicellulose (HC) decreased. In addition, the average molecular weight of WSP increased while the average molecular weight of NSP decreased. Secondly, the drying time of plums with different postharvest ripening periods was in the order: D3 < D4 < D2 < D1 < D0 < D5 < D6. Furthermore, the sugar content of dried plums was mainly influenced by drying time, with three stages of sugar changes observed, tied to moisture content: (1) Sucrose hydrolyzes (50-85%); (2) Fructose and glucose degrade (15-50%); (3) Sorbitol degrades (15-42%). These findings indicate that the transformation of cell wall pectin profile during the postharvest ripening process alters drying behavior and regulates the sugar content of dried plums. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Galacturonic acid (PubChem CID: 439215); Acetone (PubChem CID: 180); Distilled water (PubChem CID: 962); Trans-1,2-Diaminocyclohexane-N, N, N, N'-tetraacetic acid (PubChem CID: 2723845); Na2CO3 (PubChem CID: 10340); Glucose (PubChem CID: 5793); fructose (PubChem CID: 2723872) sucrose (PubChem CID: 5988) sorbitol (PubChem CID: 5780) and Sodium borohydride (PubChem CID: 4311764).


Assuntos
Parede Celular , Frutas , Pectinas , Pectinas/metabolismo , Pectinas/química , Pectinas/análise , Parede Celular/química , Parede Celular/metabolismo , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Dessecação , Prunus domestica/química , Prunus domestica/metabolismo , Prunus domestica/crescimento & desenvolvimento , Açúcares/metabolismo , Açúcares/análise , Manipulação de Alimentos
4.
Food Chem ; 454: 139746, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38795624

RESUMO

The influence of four microbial biostimulants containing various strains of Bacillus subtilis and/or Paenibacillus sp. on the quality of raspberries cv. Delniwa, Poemat, and Enrosadira cultivated in two consecutive seasons was investigated. The biostimulants influenced the antioxidant level, antioxidant capacity, phenolic acids and flavonoids profiles, enzymatic activity, and the degree of methylation and acetylation of the pectin in the raspberry fruits. The biostimulants had the greatest effect on the antioxidant content (16% - 20% increase) and capacity in the Delniwa raspberry fruits from the first season. A positive correlation was found between the activity of the ß-galactosidase enzyme and ferric reducing power. In the second season, a decrease in the activity of pectin esterase and α-L-arabinofuranosidase and an increase in the degree of methylation of pectin were noted. Our results suggest that the changes in raspberry quality were related to the type of biostimulant applied.


Assuntos
Antioxidantes , Bacillus subtilis , Frutas , Rubus , Antioxidantes/metabolismo , Antioxidantes/análise , Rubus/química , Rubus/microbiologia , Rubus/crescimento & desenvolvimento , Rubus/metabolismo , Frutas/química , Frutas/microbiologia , Frutas/metabolismo , Bacillus subtilis/enzimologia , Bacillus subtilis/química , Paenibacillus/enzimologia , Paenibacillus/metabolismo , Pectinas/metabolismo , Pectinas/análise , Hidrolases de Éster Carboxílico
5.
Molecules ; 29(8)2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38675700

RESUMO

Crispbread is gaining popularity as a healthy snack or bread substitute. This is a lightweight dry type of flat food that stays fresh for a very long time due to its lack of water and usually contains different types of grain flour, including gluten-containing wheat or rye flour. The incorporation of legume purée into crispbread represents an innovative approach to enhancing the nutritional profile and taste of the product. The rheological properties of various legume purées (chickpea, white bean, black bean, and red bean) mixed with citrus pectin were examined, revealing significant differences in fluid behavior and viscosity. Crispbread formulations were analyzed for water content and activity, color, structure, FT-IR spectra, water vapor adsorption isotherms, and sensory evaluation. The results showed the possibility of obtaining crispbread based on the purée of legumes and citrus pectin. Crispbread enriched with red bean purée exhibited low water activity (0.156) and water content (3.16%), along with a continuous porous structure, and received the highest sensory evaluation score among the products. These findings can be treated as a basis for the development of other innovative recipes and combinations using legumes.


Assuntos
Fabaceae , Reologia , Fabaceae/química , Verduras/química , Viscosidade , Pectinas/química , Pectinas/análise , Farinha/análise , Pão/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
6.
Methods Mol Biol ; 2791: 57-70, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38532092

RESUMO

Immunohistochemistry is a method that allows the detection of individual components of cell walls in an extremely precise way at the level of a single cell and wall domains. The cell wall antibodies detect specific epitopes of pectins, arabinogalactan proteins (AGP), hemicelluloses, and extensins. The presented method visualization of the selected pectic and AGP epitopes using antibodies directed to wall components is described. The method of the analysis of the chemical composition of the wall is present on the example of the shoot apical meristems of Fagopurum esculentum and Fagopyrum tataricum. Recommended protocols for immunostaining and examination on fluorescence microscopy level are presented.


Assuntos
Fagopyrum , Fagopyrum/química , Fagopyrum/metabolismo , Meristema/metabolismo , Pectinas/análise , Imuno-Histoquímica , Epitopos , Parede Celular/química
7.
Carbohydr Polym ; 327: 121693, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38171698

RESUMO

Cell wall polysaccharides were isolated by sequential extractions from coffee pulp, the main solid waste from coffee processing. Extractions were conducted with distilled water at room and boiling temperatures, 0.5 % ammonium oxalate and 0.05 M Na2CO3 to obtain pectic fractions. Hemicelluloses were extracted by using 2 M and 4 M NaOH. The composition of the hemicellulose fractions suggested the presence of xyloglucans, galactomannans and arabinogalactan-proteins (AGPs). The main part of the cell wall polysaccharides recovered from coffee pulp were pectins branched with arabinogalactans. Coffee pulp pectic fractions were low-methoxylated with various amounts of protein (0.5-8.4 %) and phenolics (0.7-8.5 %). Detection at 280 nm in the HPSEC analyses and radial gel diffusion assay using Yariv reagent indicated the presence of AGPs in most of these fractions. NMR analyses of chelating agent (CSP) and dialyzed water (WSPD) extracted pectins were carried out. The results demonstrated that CSP contains only AG I. On the other hand, AG I and AG II are present in WSPD, probably covalently linked to the pectic portion. Comparison with the literature indicated similarities between the cell wall polysaccharides from coffee pulp and green coffee beans.


Assuntos
Coffea , Coffea/química , Polissacarídeos/química , Pectinas/análise , Água/análise , Parede Celular/química
8.
Food Res Int ; 177: 113836, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38225113

RESUMO

An acidic beverage was formulated with xanthan gum (XG), pectin (P) and brewer spent grain (BSG) peptides with antioxidant and antihypertensive properties. The impact of hydrocolloids levels on peptide bioaccessibility was studied. Peptides were obtained from BSG using Purazyme and Flavourzyme enzymes. BSG peptides were fractionated by ultrafiltration (UF) and four fractions were obtained: F1 (>10 kDa), F2 (10-5 kDa), F3 (1-5 kDa), and F4 (<1 kDa). F3 showed the highest protein purity, ferulic acid content, proportion of amphipathic peptides, and bioactive properties (ABTS+ radical scavenging and ACE-I inhibitory activity). The identified peptides from F3 by tandem mass spectrometry were 138. In silico analysis showed that 26 identified peptides had ABTS+ inhibitory activity, while 59 ones presented good antihypertensive properties. The effect of XG and P levels on bioaccessibility of F3 peptides in the formulated beverages was studied by a central composite experimental design. It was observed that F3 peptides interacted with hydrocolloids by electrostatic forces at pH of formulated beverages. The addition of hydrocolloids to formulation modulated the release of the antioxidant peptides and protected the degradation of ACE-I inhibitory peptides from F3 during simulated gastrointestinal digestion. Finally, the level of hydrocolloids that produced intermediate viscosities in the formulated beverages improved the bioaccessibility of the F3 peptides.


Assuntos
Anti-Hipertensivos , Antioxidantes , Benzotiazóis , Polissacarídeos Bacterianos , Ácidos Sulfônicos , Anti-Hipertensivos/química , Antioxidantes/análise , Hidrólise , Inibidores da Enzima Conversora de Angiotensina/química , Pectinas/análise , Hidrolisados de Proteína/química , Peptídeos/química , Grão Comestível/química , Coloides/análise
9.
Plant Cell Environ ; 47(4): 1238-1254, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38173082

RESUMO

The evolution of land flora was an epochal event in the history of planet Earth. The success of plants, and especially flowering plants, in colonizing all but the most hostile environments required multiple mechanisms of adaptation. The mainly polysaccharide-based cell walls of flowering plants, which are indispensable for water transport and structural support, are one of the most important adaptations to life on land. Thus, development of vasculature is regarded as a seminal event in cell wall evolution, but the impact of further refinements and diversification of cell wall compositions and architectures on radiation of flowering plant families is less well understood. We approached this from a glyco-profiling perspective and, using carbohydrate microarrays and monoclonal antibodies, studied the cell walls of 287 plant species selected to represent important evolutionary dichotomies and adaptation to a variety of habitats. The results support the conclusion that radiation of flowering plant families was indeed accompanied by changes in cell wall fine structure and that these changes can obscure earlier evolutionary events. Convergent cell wall adaptations identified by our analyses do not appear to be associated with plants with similar lifestyles but that are taxonomically distantly related. We conclude that cell wall structure is linked to phylogeny more strongly than to habitat or lifestyle and propose that there are many approaches of adaptation to any given ecological niche.


Assuntos
Plantas , Polissacarídeos , Polissacarídeos/análise , Filogenia , Plantas/química , Parede Celular/química , Pectinas/análise , Evolução Biológica
10.
Int J Biol Macromol ; 254(Pt 3): 127869, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37939773

RESUMO

There is an increasing demand for obtaining pectin from new sources. Red radish (Raphanus sativus L.) pomace pectin extracted by alkali was low-methoxyl pectin with esterification degree of 10.17 %, galacturonic acid content of 69.71 % (wt), and average molar weight of 78.59 kDa. The pectin primarily consisted of rhamnogalacturonan I and homogalacturonan domains. The predominant monosaccharides of the pectin were galacturonic acid (46.32 mol%), arabinose (16.03 mol%), galactose (10.46 mol%), and rhamnose (10.28 mol%), respectively. The red radish pomace pectin solution exhibited a shear-thinning behavior. NaCl could induce gelation of red radish pomace pectin, and the gel properties of red radish pomace pectin were considerably affected by the NaCl concentration. As the NaCl concentration (0.25-0.50 mol/L) increased, the rate of gelation accelerated, and the time to gelation point appeared earlier. There was an optimal NaCl concentration (0.50 mol/L) for the pectin to form a gel with the greatest solid-like properties, gel hardness (33.84 g) and water-holding capacity (62.41 %). Gelation force analysis indicated gel formation mainly caused by electrostatic shielding effect of Na+ and hydrogen bonding. This research could facilitate the applications of the red radish pomace pectin in the realm of edible hydrocolloids.


Assuntos
Raphanus , Cloreto de Sódio , Pectinas/análise , Ácidos Hexurônicos/análise
11.
Magn Reson Chem ; 62(4): 298-309, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37724740

RESUMO

Solid-state nuclear magnetic resonance (ssNMR) measurements of intact cell walls and cellular samples often generate spectra that are difficult to interpret due to the presence of many coexisting glycans and the structural polymorphism observed in native conditions. To overcome this analytical challenge, we present a statistical approach for analyzing carbohydrate signals using high-resolution ssNMR data indexed in a carbohydrate database. We generate simulated spectra to demonstrate the chemical shift dispersion and compare this with experimental data to facilitate the identification of important fungal and plant polysaccharides, such as chitin and glucans in fungi and cellulose, hemicellulose, and pectic polymers in plants. We also demonstrate that chemically distinct carbohydrates from different organisms may produce almost identical signals, highlighting the need for high-resolution spectra and validation of resonance assignments. Our study provides a means to differentiate the characteristic signals of major carbohydrates and allows us to summarize currently undetected polysaccharides in plants and fungi, which may inspire future investigations.


Assuntos
Celulose , Polissacarídeos , Polissacarídeos/análise , Polissacarídeos/química , Espectroscopia de Ressonância Magnética , Celulose/análise , Celulose/química , Pectinas/análise , Pectinas/química , Imageamento por Ressonância Magnética , Parede Celular/química
12.
J Sci Food Agric ; 104(6): 3216-3227, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38072678

RESUMO

BACKGROUND: Kenaf seeds are underutilized kenaf plant by-products, containing essential nutrients including dietary fiber (DF), which can be potentially utilized as food ingredients. The present study aimed to evaluate the physicochemical characteristics of kenaf seed fiber fractions extracted from kenaf seed. RESULTS: Defatted kenaf seed powder yielded four DF fractions: alkali-soluble hemicellulose (146.4 g kg-1 ), calcium-bound pectin (10.3 g kg-1 ) and acid-soluble pectin (25.4 g kg-1 ) made up the soluble fibre fraction, whereas cellulose (202.2 g kg-1 ) comprised the insoluble fraction. All fractions were evaluated for their physicochemical properties. The DF fractions contained glucose, mannose, xylose and arabinose, and a small amount of uronic acid (1.2-2.7 g kg-1 ). The isolated pectin fractions had a low degree of esterification (14-30%). All the isolated DF fractions had high average molecular weights ranging from 0.3 to 4.3 × 106 g mol-1 . X-ray diffractogram analysis revealed that the fractions consisted mainly of an amorphous structure with a relative crystallinity ranging from 31.6% to 44.1%. The Fourier-transform infrared spectroscopy spectrum of kenaf seed and its DF fractions showed typical absorption of polysaccharides, with the presence of hydroxyl, carboxyl, acetyl and methyl groups. Scanning electron microscopy analysis demonstrated that the raw material with the rigid structure resulted in soluble and insoluble DF fractions with more fragile and fibrous appearances, respectively. The soluble DF demonstrated greater flowability and compressibility than the insoluble fractions. CONCLUSION: These findings provide novel information on the DF fractions of kenaf seeds, which could be used as a potential new DF for the food industry. © 2023 Society of Chemical Industry.


Assuntos
Hibiscus , Hibiscus/química , Fibras na Dieta/análise , Pectinas/análise , Celulose/análise , Sementes/química
13.
Food Res Int ; 175: 113736, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38129046

RESUMO

Oleosomes are lipid composites providing energy storage in oilseeds. They possess a unique structure, comprised of a triglyceride core stabilized by a phospholipid-protein membrane, and they have shown potential to be used as ingredients in several food applications. Intact oleosomes are extracted by an aqueous process which includes soaking, milling, and gravitational separation. However, the details of the complexes formed between oleosomes, proteins and pectin polysaccharides during this extraction are not known. It was hypothesized that pectins play an important role during the oleosome separation, and different proteins will be complexed on the surface of the oleosomes, depending on the pH of extraction. Rapeseed extracts were treated with and without pectinase (Pectinex Ultra SP-L) and extracted at pH 5.7 or 8.5, as this will affect electrostatic complexation. Acidic conditions led to co-extraction of storage proteins, structured as dense oleosome emulsions, stabilized by a network of proteins and polysaccharides. Pectinase intensified this effect, highlighting pectic polysaccharides' role in bridging interactions among proteins and oleosomes under acidic conditions. The presence of this dense interstitial layer around the oleosomes protected them from coalescence during extraction. Conversely, under alkaline conditions, the extraction process yielded more purified oleosomes characterized by a larger particle size, most likely due to coalescence. Nevertheless, pectinase addition at pH 8.5 mitigated coalescence tendencies. These results contribute to a better understanding of the details of the colloidal complexes formed during extraction and can be used to modulate the composition of the extracted fractions, with significant consequences not only for yields and purity but also for the functional properties of the ingredients produced.


Assuntos
Brassica napus , Brassica rapa , Gotículas Lipídicas/química , Pectinas/análise , Poligalacturonase , Brassica rapa/química
14.
Int J Biol Macromol ; 258(Pt 2): 128958, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38154707

RESUMO

The level of polysaccharides in the mature Lycium barbarum fruit (LBF) cell wall depends on their metabolism, trafficking, and reassembly within the cell. In this study, we examined the composition, content, and ultrastructure of the cell wall polysaccharides of LBF during maturation, and further analyzed cell wall polysaccharide remodeling using isotope tagging with relative and absolute quantification (iTRAQ)-based proteomics. The results showed that the contents of cellulose and hemicellulose tended to increase in the pre-maturation stage and decrease in the later stage, while pectin level increased before fruit maturing. The differential expression of the 54 proteins involved in the metabolic pathways for glucose, fructose, galactose, galacturonic acid and arabinose was found to be responsible for these alterations. The work provides a biological framework for the reorganization of polysaccharides in the LBF cell wall, and supports the hypothesis that pectic polysaccharide glycosyl donors come from starch, cellulose, hemicellulose and isomorphic pectin.


Assuntos
Lycium , Pectinas , Pectinas/análise , Lycium/química , Frutas/química , Polissacarídeos/química , Celulose/análise , Parede Celular
15.
J Sci Food Agric ; 104(6): 3532-3542, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38146066

RESUMO

BACKGROUND: Flavor is considered as a key quality attribute of fruit juice affecting consumer acceptance. During processing, the flavor loss of cloudy juice always occurs due to the variations of juice cloud particles. Pectin, a major component of cloud particles, plays an important role in cloud stability. In this work, we focused on the effects of variation of three pectin fractions caused by gentle centrifugation and clarification on the physicochemical properties, volatile content and sensory profile of heat-sterilized muskmelon cloudy juice. RESULTS: Centrifugation treatment reduced the total soluble solids and viscosity of cloudy juice and increased cloud stability. With centrifugation increased, the contents of most monosaccharides in the three pectin fractions were reduced. Most aroma-active aldehydes and alcohols, such as (2E,6Z)-nonadienal, 1-octen-3-ol and (E)-non-2-enal, after gentle centrifugation and clarification, were maintained, but most esters were decreased. The volatile compositions were highly related to the three pectin fractions. The addition of chelator-soluble pectin and sodium carbonate-soluble pectin could decrease the formation of dimethyl trisulfide and dimethyl disulfide in clarified juice, thereby improving the sensory profile. CONCLUSION: The results suggested that endogenous chelator-soluble pectin and sodium carbonate-soluble pectin can be used in heat-sterilized fruit juice to improve flavor quality, with an emphasis on a significant reduction in volatile sulfur compounds. © 2023 Society of Chemical Industry.


Assuntos
Carbonatos , Temperatura Alta , Pectinas , Pectinas/análise , Frutas/química , Quelantes
16.
Food Res Int ; 173(Pt 2): 113357, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803698

RESUMO

The effects of postharvest melatonin (MT) treatment on cuticular wax and cell wall metabolism in blueberry fruit (Vaccinium spp.) were evaluated. The results revealed that MT treatment maintained the cuticular wax rod-like structure and delayed wax degradation. The gas chromatography-mass spectrometry analysis results revealed that MT application changed the cuticular wax composition in blueberries, and 25 metabolic components were screened. The metabolic regulation of wax quality in blueberry fruit may therefore be influenced by MT. Additionally, MT slowed down pectin and cellulose degradation by reducing the activities of cell wall degrading enzymes like pectin methyl esterase polygalacturonase, ß-galactosidase, and cellulose in the later stages of storage. It also downregulated the transcriptional expression of related genes like VcPE, VcPG, VcBG6, and VcGAL1. Thus, MT prevented softening and senescence by postponing the degradation of the cell wall in postharvest blueberry fruit.


Assuntos
Mirtilos Azuis (Planta) , Melatonina , Humanos , Mirtilos Azuis (Planta)/química , Melatonina/farmacologia , Melatonina/análise , Melatonina/metabolismo , Frutas/química , Tempo para o Tratamento , Pectinas/análise , Celulose/análise , Parede Celular/química
17.
Structure ; 31(11): 1375-1385, 2023 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-37597511

RESUMO

Structural analysis of macromolecular complexes within their natural cellular environment presents a significant challenge. Recent applications of solid-state NMR (ssNMR) techniques on living fungal cells and intact plant tissues have greatly enhanced our understanding of the structure of extracellular matrices. Here, we selectively highlight the most recent progress in this field. Specifically, we discuss how ssNMR can provide detailed insights into the chemical composition and conformational structure of pectin, and the consequential impact on polysaccharide interactions and cell wall organization. We elaborate on the use of ssNMR data to uncover the arrangement of the lignin-polysaccharide interface and the macrofibrillar structure in native plant stems or during degradation processes. We also comprehend the dynamic structure of fungal cell walls under various morphotypes and stress conditions. Finally, we assess how the combination of NMR with other techniques can enhance our capacity to address unresolved structural questions concerning these complex macromolecular assemblies.


Assuntos
Células Vegetais , Polissacarídeos , Células Vegetais/química , Células Vegetais/metabolismo , Polissacarídeos/química , Espectroscopia de Ressonância Magnética , Parede Celular/metabolismo , Pectinas/análise , Pectinas/química , Pectinas/metabolismo
18.
Food Chem ; 427: 136745, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37392633

RESUMO

Submicroparticles are important components generally existed in chrysanthemum tea infusion, but their functionality, chemical composition, structure and self-assembly mechanism are unclear due to lack of suitable preparation method and research strategy. This study showed that submicroparticles promoted the intestinal absorption of phenolics in chrysanthemum tea infusion by comparison of chrysanthemum tea infusion, submicroparticles-free chrysanthemum tea infusion and submicroparticles. Submicroparticles efficiently prepared by ultrafiltration mainly consisting of polysaccharide and phenolics accounted for 22% of total soluble solids in chrysanthemum tea infusion. The polysaccharide, which was determined as esterified pectin with a spherical conformation, provided spherical skeleton to form submicroparticles. A total of 23 individual phenolic compounds were identified in submicroparticles with the total phenolic content of 7.63 µg/mL. The phenolics not only attached to the external region of spherical pectin by hydrogen bonds, but also got into hydrophobic cavities of spherical pectin and attached to the internal region by hydrophobic interactions.


Assuntos
Chrysanthemum , Chrysanthemum/química , Flores/química , Pectinas/análise , Antioxidantes/análise , Fenóis/análise , Chá/química
19.
Carbohydr Polym ; 316: 121065, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37321745

RESUMO

The lotus (Nelumbo nucifera Gaertn.) is the largest aquatic vegetable in Asia. The lotus seedpod (LS) is an inedible part of the mature flower receptacle of the lotus plant. However, the polysaccharide isolated from the receptacle has been less studied. The purification of LS resulted in two polysaccharides (LSP-1 and LSP-2). Both polysaccharides were found to be medium-sized HG pectin, with a Mw of 74 kDa. Their structures were elucidated via GC-MS and NMR spectrum and proposed as the repeating sugar units of GalA connected via α-1,4-glycosidic linkage, with LSP-1 having a higher degree of esterification. They have certain content of antioxidant and immunomodulatory activities. The esterification of HG pectin would have an adverse effect on these activities. Furthermore, the degradation pattern and kinetics of LSPs by pectinase conformed to the Michaelis-Menten model. There is a large amount of LS, resulting from the by-product of locus seed production, and thus a promising source for the isolation of the polysaccharide. The findings of the structure, bioactivities, and degradation property provide the chemical basis for their applications in the food and pharmaceutical industries.


Assuntos
Antioxidantes , Lotus , Antioxidantes/química , Lotus/química , Sementes/química , Polissacarídeos/química , Pectinas/análise
20.
J Oleo Sci ; 72(6): 605-612, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37258214

RESUMO

Quince fruit powder can be obtained from the waste of the edible product. In this study, we modified the powder with various solvents and investigated its application in Pickering emulsification. The crushed Chinese quince fruit possessed excellent Pickering emulsifying abilities when the water-soluble components were removed. In addition to cellulose, the powder contains hydrophilic pectin and hydrophobic lignin fibers. Similarly, a powder consisting of cellulose and a small amount of lignin without pectin, which was obtained by further solvent treatment, also showed high emulsification performance. Although these two powders had different fiber compositions, their water contact angles were almost equal, and their surface hydrophilicity was lower than that of the cellulose-only powder without emulsification ability.


Assuntos
Emulsões , Frutas , Rosaceae , Celulose/química , Emulsões/química , Frutas/química , Lignina/química , Pectinas/análise , Pós , Rosaceae/química , Tensoativos/química , Água/química
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