Polysaccharides from sunflower stalk pith: Chemical, structural and functional characterization

Star anise (Illicium verum Hook. F.) polysaccharides: Potential therapeutic management for obesity, hypertension, and diabetes

This study explores the extraction of polysaccharides from star anise (Illicium verum Hook. f.) with its anti-obesity, antihypertensive, antidiabetic, and antioxidant properties. The aim is to optimize the extraction conditions of star anise polysaccharides (SAP) utilizing propane alcohols-based deep eutectic solvents and microwave-assisted methods. The optimized conditions resulted in an extraction yield of 5.14%. The characteristics of acidic pectin-like SAP, including high viscosity (44.86 mPa s), high oil-holding capacity (14.39%), a high degree of esterification (72.53%), gel-like properties, highly amorphous, a high galacturonic acid concentration, and a highly branching size polysaccharide structure, significantly contribute to their potent inhibition of pancreatic lipase (86.67%), angiotensin-converting enzyme (73.47%), and α-glucosidase (82.33%) activities as well as to their antioxidant properties of azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS, 34.94%) and ferric ion reducing antioxidant power (FRAP, 0.56 mM FeSO4). Therefore, SAP could be used as a potential therapeutic agent for obesity, hypertension, and diabetes mellitus management.

Effects of physical method and enzymatic hydrolysis on the properties of soybean fiber-rich stabilizer for oil in water emulsions

BACKGROUND

Okara is a by-product from the soybean industry and an abundant resource of insoluble soybean fiber (ISF). ISF with various properties could be obtained by different extraction methods. It is an attractive option to utilize okara by taking advantage of ISF as an emulsifier or stabilizer.

RESULTS

Compared with the untreated ISF (ISFUT ), superfine grinding reduced the particle size and viscosity of ISF (ISFSG ). Steam explosion increased the water solubility from 17.5% to 51.7% but decreased the water holding capacity and swelling capacity of ISF (ISFSE ) from 15.0 and 14.0 g/g to 4.2 and 3.3 g/g, respectively. Emulsions prepared by ISFUT and ISFSG before or after enzymatic hydrolysis presented large oil droplets and were unstable. Although emulsions prepared by ISFSE after enzymatic hydrolysis (ISFSE-E ) showed flocculation, the volume-weighted average diameter (19.7 μm) were the smallest while the viscosity and viscoelastic modulus were the highest, and exhibited excellent physical stability during storage.

CONCLUSION

ISF obtained by physical and hydrolysis treatment displayed diverging physicochemical properties while ISF prepared by steam explosion-enzymatic hydrolysis presented the best potential to stabilize emulsions. The present study could provide novel information about the utilization of okara by the application of ISF as an emulsifier or stabilizer. © 2023 Society of Chemical Industry.

Fractionation and characterisation of pectin-rich extracts from garlic biomass

Polysaccharides from garlic waste leaf and skin biomass have been isolated using a sequential extraction protocol and characterised using constituent sugar composition and linkage analysis, spectroscopy, chromatography and dilute solution viscometry. The results revealed that the isolated polysaccharides were predominantly pectins. The predominant monosaccharide in all samples was galacturonic acid (>61 %), followed by galactose and rhamnose. The pectins extracted from skin biomass were mainly homogalacturonan (83-91 %), whereas those extracted from leaf biomass comprised both homogalacturonan (62-65 %) and rhamnogalacturonan-I (35-38 %). The degree of methyl esterification of uronic acids in all samples was 44-56 %. The peak molecular weight of the main polysaccharide population in each sample was ∼ 350 x103 g/mol, with leaf extracts and the skin acidic extract containing a second, lower molecular weight peak. Overall, waste garlic biomass is a potential resource for commercial pectin extraction for use in food or pharmaceutical industries.

Chemical basis and self-assembly mechanism of submicroparticles forming in chrysanthemum tea infusion

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.

Mycelial biomass and intracellular polysaccharides production, characterization, and activities in Auricularia auricula-judae cultured with different carbon sources

The carbon source, an essential factor for submerged culture, affects fungal polysaccharides production, structures, and activities. This study investigated the impact of carbon sources, including glucose, fructose, sucrose, and mannose, on mycelial biomass and the production, structural characterization, and bioactivities of intracellular polysaccharides (IPS) produced by submerged culture of Auricularia auricula-judae. Results showed that mycelial biomass and IPS production varied with different carbon sources, where using glucose as the carbon source produced the highest mycelial biomass (17.22 ± 0.29 g/L) and IPS (1.62 ± 0.04 g/L). Additionally, carbon sources were found to affect the molecular weight (Mw) distributions, monosaccharide compositions, structural characterization, and activities of IPSs. IPS produced with glucose as the carbon source exhibited the best in vitro antioxidant activities and had the strongest protection against alloxan-damaged islet cells. Correlation analysis revealed that Mw correlated positively with mycelial biomass (r = 0.97) and IPS yield (r = 1.00), while IPS antioxidant activities correlated positively with Mw and negatively with mannose content; the protective activity of IPS was positively related to its reducing power. These findings indicate a critical structure-function relationship for IPS and lay the foundation for utilizing liquid-fermented A. aruicula-judae mycelia and the IPS in functional food production.

Comparison of structures and emulsifying properties between water-extracted pectins from Fructus aurantii

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-GalpA-(1 → and →4)-α-GalpA-6-O-methyl-(1→, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides.

Enzyme-extracted raspberry pectin exhibits a high-branched structure and enhanced anti-inflammatory properties than hot acid-extracted pectin

To characterize the structure of purified raspberry pectin and discuss the impact of different extraction methods on the pectin structure, raspberry pectin was extracted by hot-acid and enzyme method and purified by stepwise ethanol precipitation and ion-exchange chromatography isolation. Enzyme-extracted raspberry pectin (RPE50%-3) presented relatively intact structure with molecular weight of 5 × 10⁴ g/mol and the degree of methylation was 39%. The 1D/2D NMR analysis demonstrated RPE50%-3 was a high-branched pectin mainly containing 50% homogalacturonan, 16% branched α-1,5-arabinan and α-1,3-arabinan, 18% β-1,4-galactan and β-1,6-galactan. Acid-extracted raspberry pectin (RPA50%-3) contained less arabinan than RPE50%-3. Moreover, RPE50%-3 inhibited the nitric oxide (NO), TNF-α, IL-6 production of lipopolysaccharide-induced macrophages by 67%, 22% and 46% at the dosage of 200 ug/mL, while the inhibitory rate of RPA50%-3 were 33%, 9%, and 1%, respectively. These results suggested that enzyme-extracted raspberry pectin contained more arabinan sidechains and exhibited better immunomodulatory effect.

Sunflower Bark Extract as a Biostimulant Suppresses Reactive Oxygen Species in Salt-Stressed Arabidopsis

A survey of plant-based wastes identified sunflower (Helianthus annuus) bark extract (SBE), produced via twin-screw extrusion, as a potential biostimulant. The addition of SBE to Arabidopsis (Arabidopsis thaliana) seedlings cultured in vitro showed a dose-dependent response, with high concentrations causing severe growth inhibition. However, when priming seeds with SBE, a small but significant increase in leaf area was observed at a dose of 0.5 g of lyophilized powder per liter. This optimal concentration of SBE in the culturing medium alleviated the growth inhibition caused by 100 mM NaCl. The recovery in shoot growth was accompanied by a pronounced increase in photosynthetic pigment levels and a stabilization of osmotic homeostasis. SBE-primed leaf discs also showed a similar protective effect. SBE mitigated salt stress by reducing the production of reactive oxygen species (ROS) (e.g., hydrogen peroxide) by about 30% and developing more expanded true leaves. This reduction in ROS levels was due to the presence of antioxidative agents in SBE and by activating ROS-eliminating enzymes. Polyphenols, carbohydrates, proteins, and other bioactive compounds detected in SBE may have contributed to the cellular redox homeostasis in salt-stressed plants, thus promoting early leaf development by relieving shoot apical meristem arrest. Sunflower stalks from which SBE is prepared can therefore potentially be valorized as a source to produce biostimulants for improving salt stress tolerance in crops.

A Comparative Investigation on Structural and Chemical Differences between the Pith and Rind of Sunflower Stalk and Their Influences on Nanofibrillation Efficiency

The structure and chemical composition of cell walls play a vital role in the bioconversion and utilization of plants. In the present study, the cell wall structure and chemical composition of pith and rind from sunflower stalks were compared and correlated to their nanofibrillation efficiency with ultrasonic treatment. Mild chemical pretreatment using 1% or 4% NaOH without any bleaching process were applied prior to ultrasonication nanofibrillation. Significant structural and chemical differences were demonstrated between the pith and rind, with the former exhibiting a much lower lignin and hemicellulose contents, higher pectin, much looser cell structure and higher cell wall porosity than the latter. Alkaline treatment alone was sufficient to eliminate most of the hemicellulose and pectin from stalk pith, whereas only partial removal of hemicellulose and lignin was achieved for the woody rind part. After 30 min of ultrasonic treatment, the stalk pith exhibited fully defibrillated fibrils with a continuous and entangled micro/nanofibrillated network, whereas numerous micron-sized fiber and fragments remained for the rind. The results indicated that stalk pith is less recalcitrant and easier to be fibrillated with ultrasonication than rind, which must be correlated to their distinct differences in both structure and chemical composition.

Multi-level fingerprinting and cardiomyocyte protection evaluation for comparing polysaccharides from six Panax herbal medicines

The role of polysaccharides in quality control of ginseng is underestimated. Large-scale comparison on the polysaccharides of Panax ginseng (PG), P. quinquefolius (PQ), P. notoginseng (PN), Red ginseng (RG), P. japonicus (ZJS), and P. japonicus var. major (ZZS), was performed by both chemical and biological approaches. Holistic fingerprinting at polysaccharide and the hydrolyzed oligosaccharide and monosaccharide levels utilized various chromatography methods, while OGD and OGD/R models on H9c2 cells were introduced to evaluate the protective effects on cell viability and mitochondrial function. Polysaccharides from six ginseng species exhibited remarkable content difference (RG > PG/ZZS/ZJS/PQ > PN), but weak differentiations in molecular weight distribution and oligosaccharide profiles, while Glc and GalA were richer for monosaccharide compositions of PG and RG polysaccharides, respectively. RG polysaccharides (25/50/100 μg/mL) showed significant cardiomyocyte protection by regulating mitochondrial functions. These new evidences may provide support for the supplementary role of polysaccharides in quality control of ginseng.

Revalorization of sunflower stalk pith as feedstock for the coproduction of pectin and glucose using a two-step dilute acid pretreatment process

BACKGROUND

Sunflower stalk pith, residue from the processing of sunflower, is rich in pectin and cellulose, thereby acting as an economic raw material for the acquisition of these compounds. In order to increase the commercial value of sunflower processing industry, a two-step dilute sulfuric acid treatment process was conducted on spent sunflower stalk pith to obtain the value-added products, pectin and glucose.

RESULTS

In this study, pectin was firstly extracted under mild acid condition to avoid pectin degradation, which was conducted at 90 °C with a pH of 2.0 for 2 h, and ~0.14 g/g of pectin could be recovered. Then the remaining solids after pectin extraction were subjected to the reinforced treatment process with 0.75% H₂SO₄ at 150 °C for 30 min to further improve enzymatic hydrolysis efficiency. Moreover, by combining a fed-batch enzymatic hydrolysis strategy, a solid loading content of 16% was successfully achieved and the glucose titer reached 103.1 g/L with a yield of 83.6%.

CONCLUSION

Finally, ~140 g pectin and 260 g glucose were produced from 1 kg of raw sunflower stalk pith using the integrated biorefinery process. This work puts forward a two-step dilute acid pretreatment combined with enzymatic hydrolysis method to produce pectin and glucose from sunflower spent waste.

Extraction, Characterization, and Applications of Pectins from Plant By-Products

Currently, pectins are widely used in the cosmetic, pharmaceutical, and food industries, mainly as texturizing, emulsifying, stabilizing, and gelling agents. Pectins are polysaccharides composed of a large linear segment of α-(1,4) linked d-galactopyranosyluronic acids interrupted by β-(1,2)-linked l-rhamnoses and ramified by short chains composed of neutral hexoses and pentoses. The characteristics and applications of pectins are strongly influenced by their structures depending on plant species and tissues but also extraction methods. The aim of this review is therefore to highlight the structures of pectins and the various methods used to extract them, including conventional ones but also microwave heating, ultrasonic treatment, and dielectric barrier discharge techniques, assessing physico-chemical parameters which have significant effects on pectin characteristics and applications as techno-functional and bioactive agents.

Adsorption of Indigo Carmine dye onto the surface-modified adsorbent prepared from municipal waste and simulation using deep neural network

A new adsorbent was prepared from municipal wastes (a mixture of Corn Stover, Paper Waste, and Yard Waste) by cationization with 3 ̶ Chloro ̶ 2 ̶ Hydroxypropyl Trimethylammonium Chloride. The FTIR spectrum confirmed the quaternary ammonium group's presence on the adsorbent surface (1450 cm^-1). The maximum adsorption capacity (148 mg/g) was higher than the earlier reported values. Liu isotherm described well the adsorption process, with a high R²_adj value (0.997). The pseudo-first-order equation fits well for kinetic data, and thermodynamic experiments demonstrated the endothermic nature of the adsorption. The deep neural network (DNN) is applied to simulate the adsorption process, which outperformed the classical machine learning and shallow neural network models. The DNN model predicted accurately the adsorption process with the lowest deviation from the actual values with Mean Absolute Error (MAE = 3.2), Root Mean Squared Error (RMSE = 4.89), and the highest performance accuracy of R² (0.96) as compared to various classical ML algorithms such as Linear Regressions (MAE = 12.53, RMSE = 18.01, R² = 0.42), Random Forest (MAE = 5.81, RMSE = 10.05, R² = 0.82), and Extra Trees (MAE = 4.35, RMSE = 8.22, R² = 0.88). The utilized DNN model can be used for predicting the removal efficiency of dyes for various combinations of input parameters without going through laboratory experiments.