Structural and physicochemical changes in guar gum by alcohol–acid treatment

Oral polysaccharide-coated liposome-modified double-layered nanoparticles containing anthocyanins: preparation, characterization, biocompatibility and evaluation of lipid-lowering activity in vitro

Anthocyanins (ACNs) systems encapsulated in nanomaterials have received widespread attention and rapid development due to its good delivery potential. Here, the favorable benefits of four natural polysaccharide food additives coated ACNs-liposome nanoparticles (ACNs-Lipo NPs) on the stability and possible lipid-lowering effects of ACNs are discussed in this work. The polysaccharides were coupled to the ACNs-Lipo NPs and self-assembled to create ACNs-Lipo@polysaccharide NPs. The impact of various polysaccharides on the physical, chemical, and stability characteristics of NPs was examined. We found that the NPs prepared with gum arabic (GA) had the best stability. FT-IR and XRD analysis revealed electrostatic adsorption and hydrogen binding forces between the components, as well as an amorphous structure. A series of tests in vitro confirmed the excellent stability, bioavailability, antioxidant activity, and biocompatibility of NPs. Finally, cellular antioxidant activity (CAA) and oleic acid (OA)-induced lipid deposition cell models revealed that ACNs-Lipo@GA might be more readily absorbed by cells, resulting in improved antioxidant activity and lipid-lowering impact, with possible targeted delivery qualities and lipid-lowering effect.

Synthesis and characterization of novel guar gum based waste material derived nanocomposite for effective removal of hexabromocyclododecane and lindane

Herein, efficient degradation of hexabromocyclododecane (HBCD) and Lindane, a persistent organic pollutant using guar gum based calcium oxide doped silicon dioxide (GG-CaO@SiO2) has been reported. The nanocomposite was prepared by waste egg shell (CaO) and rice husk (SiO2) was well characterized. The maximum degradation of HBCD and Lindane were observed at 8 mg catalyst loading, neutral pH, and 2 mg L-1 of pollutant amount. The photocatalytic performance of GG-CaO@SiO2 for HBCD and Lindane photodegradation was evaluated, and it was found that the rate constant increased in the order of GG-CaO@SiO2 > CaO@SiO2 > GG. The polymeric GG-CaO@SiO2 nanocomposite showed maximum removal of both pollutants due to higher surface area (70 m2 g-1) and synergistic interactions among GG moieties. It achieved HBCD and Lindane elimination rates of 94 % and 90 % by photo-adsorptive degradation within 150 min. Meanwhile, the leaching of HBCD from expanded polystyrene (EPS) materials (0.14 ± 0.05 ppm) underwater with different time intervals and degradation of leachate HBCD were also assessed. The eradication of the pollutant manifested first-order kinetics, with the Langmuir adsorption. LC-MS analysis confirmed that GG-CaO@SiO2 effectively breaks down complex structure toxic pollutants into safer metabolites under natural sunlight exposure. The polymeric GG-CaO@SiO2 nanocomposite showed notable reusability up to ten cycle promotes sustainability.

Tamarind seed polysaccharide-guar gum buccal films loaded with resveratrol-bovine serum albumin nanoparticles: Preparation, characterization, and mucoadhesiveness assessment

Mucoadhesive films based on tamarind seed polysaccharide and guar gum (TSP-GG) were formulated for buccal delivery of resveratrol. Resveratrol-bovine serum albumin nanoparticles (Res-BSA) were prepared and dispersed in TSP-GG to improve its buccal mucoadhesiveness. The impregnation of Res-BSA induced the dense internal structures of TSP-GG and improved its strength and rigidity. Structural characterization showed that resveratrol existed in an amorphous state in the films containing Res-BSA, and hydrogen bonding was formed between Res-BSA and the film matrices. The films containing Res-BSA exhibited good uniformity in thickness, weight, and resveratrol content, and their surface pH was near neutral, ranging between 6.78 and 7.09. Increasing Res-BSA content reduced the water contact angle of TSP-GG (from 75.9° to 59.6°). The swelling and erosion studies indicated the favorable hydration capacity and erosion resistance of the films containing Res-BSA. Additionally, the addition of Res-BSA imparted enhanced ex vivo mucoadhesive force, in the range of 1.53 N to 1.98 N, and extended ex vivo residence time, between 17.9 h and 18.9 h, to TSP-GG. The current study implied that the composite systems of TSP-GG and Res-BSA may be a novel platform for buccal mucosal delivery of resveratrol.

Films properties of QPM corn starch with Delonix regia seed galactomannan as an edible coating material

Plant-based polysaccharides are considered a good alternative for obtaining edible films and coatings. In this research the objective was to determine the physicochemical characteristics of corn starch obtained from QPM Sac-Beh (SBCS) and Delonix regia galactomannan (DRG) and use them to produce films. Films were elaborated from 1 %(w/v) film-forming solutions (FFS) with SBCS:DRG 1:0, 1:1, and 0:1 ratio. Some films were prepared with glycerol 0.4 %(w/v) and vanillin 0.1 %(w/v). SBCS and DRG were characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. SBCS presented low crystallinity which agrees with a low gelatinization ΔH observed. The SBCS:DRG 1:0 FFS without glycerol did not form films; however, DRG addition allows film formation. It was also found that glycerol addition reduced tensile strength to 10.3 MPa, from 41.3 MPa. The lowest water vapor permeability was found in films with 1:1 SBCS:DRG and 0.1 %(w/v) vanillin. This formulation was used to coat D'Anjou pears. This coating conserved the pears' color for 24 days while the control ones started to get a brown color on day 6. Based on the results obtained, FFS elaborated with 1:1 SBCS:DRG and 0.1 %(w/v) vanillin had potential use as edible film material for coating on climacteric fruits preservation.

Hydrogels dressings based on guar gum and chitosan: Inherent action against resistant bacteria and fast wound closure

Hydrogels made with depolymerized guar gum, oxidized with theoretical oxidation degrees of 20, 35 and 50 %, were obtained via Schiff's base reaction with N-succinyl chitosan. The materials obtained were subjected to characterization by FT-IR, rheology, swelling, degradation, and morphology. Additionally, their gelation time categorized all three hydrogels as injectable. The materials' swelling degrees in Phosphate-Buffered Saline (PBS) were in the range of 26-35 g of fluid/g gel and their pore size distribution was heterogeneous, with pores varying from 67 to 93 μm. All hydrogels degraded in PBS solution, but maintained around 40 % of their initial mass after 28 days, which was more than enough time for wound healing. The biomaterials were also flexible, self-repairing, adhesive and cytocompatible and presented intrinsic actions, regardless of the presence of additives or antibiotics, against gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and gram-negative bacteria (Escherichia coli). However, the most pronounced bactericidal effect was against resistant Staphylococcus aureus - MRSA. In vivo assays, performed with 50 % oxidized gum gel, demonstrated that this material exerted anti-inflammatory effects, accelerating the healing process and restoring tissues by approximately 99 % within 14 days. In conclusion, these hydrogels have unique characteristics, making them excellent candidates for wound-healing dressings.

Application of guar (Cyamopsis tetragonoloba L.) gum in food technologies: A review of properties and mechanisms of action

With the world continuing to push toward modernization and the consumption of processed foods growing at an exponential rate, the demand for texturizing agents and natural additives has also risen as a result. It has become increasingly common to use thickening agents in food products to modify their rheological and textural properties and enhance their quality characteristics. They can be divided into (1) animal derived (chitosan and isinglass), (2) fermentation produced (xanthan and curdlan), (3) plant fragments (pectin and cellulose), (4) seaweed extracts (agar and alginate), and (5) seed flours (guar gum and locust bean gum). The primary functions of these materials are to improve moisture binding capacity, modify structural properties, and alter flow behavior. In addition, some have another responsibility in the food sector, such as the main ingredient in the delivery systems (encapsulation) and nanocomposites. A galactomannan polysaccharide extracted from guar beans (Cyamopsis tetragonolobus), known as guar gum (GG), is one of them, which has a wide range of utilities and possesses popularity among scientists and consumers. In the world of modernization, GG has found its way into numerous industries for use in food, cosmetics, pharmaceuticals, textiles, and explosives. Due to its ability to form hydrogen bonds with water molecules, it imparts significant thickening, gelling, and binding properties to the solution as well as increases its viscosity. Therefore, this study is aimed to investigate the characteristics, mechanisms, and applications of GG in different food technologies.

Enzymatically mediated Gleditsia sinensis galactomannan based hydrogel inspired by wound healing process

The self-healing property based on metal-ligand physical coordination is particularly interesting in bio-hydrogel science due to its allowance for multiple local healing events to process. As the most abundant renewable green resource in nature, Gleditsia sinensis galactomannan has great potential as a starting material for functional materials. In this study, the biocompatible Gleditsia sinensis galactomannan and cellulose were firstly chemically modified and then taken as the main constituent for constructing the metal-ligand coordination through an enzyme-regulated strategy. The hydrogel could quickly gelatinize in the surrounding environment, corresponding to the violent exothermic phenomenon, and exhibit extraordinary self-healing behavior. The molecular dynamics simulation of the hydrogel confirmed the more stable coordinated configuration from Fe(III)-chelates than Fe(II)-chelates. The morphology, mechanical property, antibacterial, and cytotoxicity of the prepared hydrogel were also studied. Our results indicated that galactomannan hydrogel based on the metal-ligand networks could balance the kinetic stability and intrinsic healability through the enzyme-induced route, which provide a new perspective in the field of biomaterial applications.

Gastrointestinal Effects and Tolerance of Nondigestible Carbohydrate Consumption

Nondigestible carbohydrates (NDCs) are food components, including nonstarch polysaccharides and resistant starches. Many NDCs are classified as dietary fibers by the US FDA. Because of their beneficial effects on human health and product development, NDCs are widely used in the food supply. Although there are dietary intake recommendations for total dietary fiber, there are no such recommendations for individual NDCs. NDCs are heterogeneous in their chemical composition and physicochemical properties-characteristics that contribute to their tolerable intake levels. Guidance on tolerable intake levels of different NDCs is needed because overconsumption can lead to undesirable gastrointestinal side effects, further widening the gap between actual and suggested fiber intake levels. In this review, we synthesize the literature on gastrointestinal effects of NDCs that the FDA accepts as dietary fibers (β-glucan, pectin, arabinoxylan, guar gum, alginate, psyllium husk, inulin, fructooligosaccharides and oligofructose, galactooligosaccharides, polydextrose, cellulose, soy fiber, resistant maltodextrin/dextrin) and present tolerable intake dose recommendations for their consumption. We summarized the findings from 103 clinical trials in adults without gastrointestinal disease who reported gastrointestinal effects, including tolerance (e.g., bloating, flatulence, borborygmi/rumbling) and function (e.g., transit time, stool frequency, stool consistency). These studies provided doses ranging from 0.75-160 g/d and lasted for durations ranging from a single-meal tolerance test to 28 wk. Tolerance was NDC specific; thus, recommendations ranged from 3.75 g/d for alginate to 25 g/d for soy fiber. Future studies should address gaps in the literature by testing a wider range of NDC doses and consumption forms (solid compared with liquid). Furthermore, future investigations should also adopt a standard protocol to examine tolerance and functional outcomes across studies consistently.

Ultrasonic depolymerization of aqueous tara gum solutions: kinetic, thermodynamic and physicochemical properties

BACKGROUND

Tara gum (TG) is characterized by its high viscosity and medium solubility, which is a result of its high molecular mass. However, for many applications, these characteristics are undesirable, making the use of TG infeasible. The present study aimed to evaluate the effect of high-intensity ultrasound on the depolymerization of aqueous solutions of TG. The effect of ultrasonication was investigated by viscometry analysis as well as Fourier transform infrared spectroscopy (FTIR) and solubility.

RESULTS

The intrinsic viscosity (η) and the molecular weight (M_w ) of TG decreased after ultrasound, achieving a molecular weight reduction of 13.50 × 10⁵  g mol^-1 after 60 min of sonication at 25 °C compared to 22.04 × 10⁵  g mol^-1 before treatment. Degradation kinetics were applied to estimate the rate constant of degradation (k). It was found that the k value of TG increased with increasing temperature from 25 to 55 °C. Partially hydrolyzed TG showed greater solubility at the two temperatures investigated (25 and 80 °C). Ultrasonic treatment did not change the chemical structure of the TG molecules according to the structural analysis by FTIR, confirming its action only as breaking the structure of the polymer.

CONCLUSION

Ultrasound is a simple method for effectively reducing the molecular weight and viscosity and increasing the solubility of TG without using chemical reagents. The synthesis of partially hydrolyzed TG expands its potential for use in food products, including as a soluble dietary fiber. © 2022 Society of Chemical Industry.

Tailormade Wheat Arabinoxylan Reveals the Role of Substitution in Regulating Gelatinization and Retrogradation Behavior of Wheat Starch

To elucidate the role of substitution of arabinoxylan (AX) in the characteristics of wheat starch, this study prepared AX with a well-defined structure by targeted enzymatic hydrolysis and comparatively investigated the effects of AX with different degrees of substitution on gelatinization and retrogradation behavior of starch. Removal of major arabinofuranosyl (Araf) of mono- or disubstituted xylopyranosyl (Xylp) of both low-molecular-weight (Mw: 62.5 kDa, Araf/Xylp: 0.61) and high-molecular-weight AX (Mw: 401.2 kDa, Araf/Xylp: 0.61) reversed the decreased gelatinization viscosity and recrystallization of amylose induced by AX to a similar extent. Upon retrogradation for 30 days, the Araf of mono- and disubstituted Xylp contributed to the water distribution and the effect depended on the molecular chain length. The C3-linked Araf of disubstituted Xylp was more involved in prohibiting the retardation of recrystallization of amylopectin, while the presence of Araf of monosubstituted Xylp might hinder the interactions between AX and amylopectin.

Diffusion of water and protein drug in 1,4-butanediol diglycidyl ether crosslinked galactomannan hydrogels and its correlation with the physicochemical properties

The aim of the present study was to obtain a better and safer galactomannan-based material for drug release applications. A novel epoxy-crosslinked galactomannan hydrogel (EGH) was prepared from guar gum using 1,4-butanediol diglycidyl ether as a crosslinking agent. The diffusion rate constant of water molecules in freeze-dried EGH positively correlated with water uptake/equilibrium swelling rate (WU/ESR), and the water molecules participated in Fickian diffusion. The ESR, WU/ESR, and bovine serum albumin (BSA) loading capacity of a customized EGH with a crosslinking density of 48.9% were 48.7 ± 0.15 g/g, 95.3%, and 56.4 mg/g, respectively. The release of BSA from freeze-dried EGH was affected by the WU/ESR and the pH; the release equilibrium time was ~40 h at pH 1.2, decreasing to ~24 h at pH 7.4. Furthermore, the cumulative release rate increased from 63.5% to 80.7% and the t₅₀ decreased from 59 to 41 min upon changing from the acidic to basic pH. The release process conformed to the Ritger-Peppas and Hixson-Crowell models, and represented Fickian diffusion and chain relaxation. The EGH showed no cytotoxicity toward HeLa cells. Together, these results demonstrate the properties of a novel galactomannan-based hydrogel that can potentially be employed as a vehicle for drug delivery.

Synthesis, characterization, and selective dye adsorption by pH- and ion-sensitive polyelectrolyte galactomannan-based hydrogels

Three novel polyelectrolyte galactomannan hydrogels (PGHs) were fabricated by chemically crosslinking quaternary ammonium galactomannan (QAG) and carboxymethyl galactomannan (CMG), and employed for the removal of Congo Red (CR) and Methylene Blue (MB). Physicochemical characterization revealed that the PGHs are chemically and physically crosslinked. The PGHs are pH- and ion-sensitive, and their physical crosslinking can be destroyed by artificial urine; water swelling capacity (100.6-321.9 g/g dry gel) and artificial urine swelling capacity (35.9-80.5 g/g dry gel). The adsorption of CR and MB was studied and found to be pH-dependent and selective. The maximum adsorption capacities of CR and MB on the QAG and CMG gels are 1441 and 94.52 mg/g, respectively, and their adsorption kinetics and isotherm behavior obey the pseudo-second-order kinetics model and Langmuir isotherm model, respectively. The adsorption mechanism is dominated by electrostatic interactions and hydrogen bonding. Further, the PGHs have excellent salt resistance and are reusable.

Facile sonochemical synthesis of Ag2O-guar gum nanocomposite as a visible light photocatalyst for the organic transformation reactions

Silver Oxide (Ag₂O)-Guar gum nanocomposite was fabricated via a simple sonochemical co-precipitation method. The obtained photocatalyst was characterized with various techniques such as X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, scanning electron microscopy and transmission electron microscopy along with energy dispersion X-ray spectroscopy. The findings have demonstrated that Ag₂O nanoparticles are spherical of 5-20 nm and were dispersed on the surface of polysaccharide guar gum to form Ag₂O-guar gum nanocomposite. The as-synthesized nanocomposite was enacted as a competent photocatalyst for the reduction of nitrobenzene and oxidation of benzyl alchohol. The conversion efficiency for the reduction of nitrobenzene was 96 % with the addition of sodium borohydride, and the conversion of benzyl alcohol was 98 %. The highly efficient photocatalytic activity was due to the exceedingly dispersed Ag₂O-guar gum nanocomposite where effective separation rate of energy driven electron-hole pairs and stronger light absorption occurs. The possible mechanism of the reactions was implicated in understanding the active species involved in the photocatalytic study.

Mannans: An overview of properties and application in food products

This review aims to emphasize the occurrence and abundant presence of mannans in nature, their classification, structural differences and significance in food and feed industry. With rising demand from the consumers' end for novel natural foods, usage of galactomannan and glucomannan has also increased alternatively. Non toxicity of mannans permits their usage in the pharmaceutical, biomedical, cosmetics, and textile industries. In the food industry, mannans have various applications such as edible films/coating, gel formation, stiffeners, viscosity modifiers, stabilizers, texture improvers, water absorbants, as prebiotics in dairy products and bakery, seasonings, diet foods, coffee whiteners etc. Applications and functions of these commonly used commercially available mannans have therefore, been highlighted. Mannans improve the texture and appeal of food products and provide numerous health benefits like controlling obesity and body weight control, prebiotic benefits, constipation alleviaton, prevent occurrence of diarrhea, check inflammation due to gut related diseases, management of diverticular disease management, balance intestinal microbiota, immune system modulator, reduced risk of colorectal cancer etc. Mannan degrading enzymes are the key enzymes involved in degradation and are useful in various industrial processes such as fruit juice clarification, viscosity reduction of coffee extracts etc. besides facilitating the process steps and improving process quality.