Degree Of Esterification Research Articles

Effects of charge distribution and degree of methylesterification of pectin emulsifier on bioaccessibility of curcumin incorporated in nanoemulsions

The objectives of this study were to elucidate the effects of degree of methyl esterification (DM) and charge distribution of pectin on the stability of emulsions and to analyze bioaccessibility of curcumin incorporated in emulsions stabilized by pectins. Three commercial pectins, CP72 (DM72), CP50 (DM50), and CP7 (DM7), were used. MP50 (DM50) with consecutive demethylesterified galacturonic acid residues was prepared from CP72 via demethylesterification to induce different charge distributions. Emulsions containing curcumin were prepared and were stored for 30 days. The CP72 and CP50 emulsions remained relatively stable for 30 days. However, MP50 and CP7 were less effective at forming stable emulsions. When the pectin emulsions passed through each phase of the simulated gastrointestinal tract (GIT), the CP72 and CP50 emulsions retained their initial droplet structures after in vitro mouth and gastric digestion, whereas the MP50 and CP7 emulsions exhibited gel-like clusters, although the gel-like formation of MP50 was distinct from that observed in CP7. MP50 emulsion showed a high degree of final lipid digestion and high bioaccessibility of curcumin while CP72 emulsion displayed a low degree of final lipid digestion. CP50 exhibited low bioaccessibility of curcumin, which might have been contributed by its fast lipid digestion profiles.

Unripe bael pulp pectin extraction and characterization using the microwave assisted method.

In this study, pectin was extracted from unripe bael using a microwave-assisted extraction technique. Optimization was done based on independent and dependent parameters. Pectin yield was the dependent variable in the study, whereas the independent factors were microwave power, time, and solid solvent ratio. Pectin extraction was carried out using different combinations of microwave power (180, 360, 540 watts), time (1, 2, 3 minutes), and the ratio of solid-solvent (1:20, 1:30, 1:40 g/mL). Using Box-Behnken response surface methodology, 17 experimental runs were performed. A microwave power of 360 watts, a time of 3 minutes, and a solid solvent ratio of 1:20 g/mL were the ideal parameters that achieved the maximum pectin yield of 19.8%. The yield of pectin was analyzed using multiple regression statistical analysis. Qualitative and quantitative analysis of pectin yield was studied, which revealed an equivalent weight of 263.15, a methoxyl content of 9.92 percent, anhydrouronic acid content of 123.2%, and a degree of esterification of 45.71%.

Optimization of Pectin Extraction from Melon Peel as a New Source of Pectin and Pectin Hydrolysate with Prebiotic Potential.

Food wastes have a large number of functional ingredients that have potential for valorization. Melon peels are increasingly produced as waste in food industries in Thailand. This study aimed to optimize pectin extraction conditions from melon peel for its prebiotic potential. Optimization was conducted using a response surface methodology and Box-Behnken experimental design. An analysis of variance indicated a significant interaction between the extraction conditions on extraction yield and degree of esterification (DE). These include pH and solvent-to-sample ratio. The conditions for the extraction of pectin with low DE (LDP), medium DE (MDP) and high DE (HDP) were optimized. Pectin hydrolysate from LDP, MDP and HDP was prepared by enzymatic hydrolysis into LPEH, MPEH and HPEH, respectively. LDP, MDP, HDP, LPEH, MPEH and HPEH were compared for their efficiency in terms of the growth of three probiotic strains, namely Lactobacillus plantarum TISTR 877, Lactobacillus casei TISTR 390 and Enterococcus faecium TISTR 1027. Among the samples tested, HPEH showed the highest ability as a carbon source to promote the growth and prebiotic activity score for these three probiotic strains. This study suggests that melon peel waste from agro-industry can be a novel source for prebiotic production.

Hydrophobic bio-composites of stearic acid starch esters and micro fibrillated cellulose processed by extrusion

Fatty acid starch esters are potential candidates for obtaining hydrophobic starch-based materials. The objective was to evaluate thermoplastic bio-composites with stearic acid cassava starch esters (SAE) as matrices reinforced with micro fibrillated cellulose (MFC). SAE with 0.11 and 0.14 of DS and native cassava starch were processed with 5 % and 10 % MFC by extrusion and then thermo-compression to obtain bio-composite films. Performance of bio-composites as a function of the degree of substitution (DS) of starch esters and the content of MFC, was evaluated. Starch esterification reduced the crystalline phase and glass transition temperature of bio-composites, as confirmed by structural and thermal analysis. The increase of DS reduced the degradation temperature, which was compensated by adding MFC, favoring thermal stability. The hydrophobicity of films increased with the degree of starch esterification. Treatments with 0.14 DS formed stiffer and less tensile strength films. There was an increase in the modulus of elasticity and a reduction in elongation by increasing MFC. Fracture microscopy of films showed defects by incomplete starch melting and lack of interfacial adhesion with MFC caused by starch esterification. Starch esterification and MFC dispersion were determinants in the performance of bio-composites. In consequence, starch esterification with stearic acid reduces the compatibility with the MFC and, consequently, the performance of composites.

Pectic polysaccharides from Tartary buckwheat sprouts: Effects of ultrasound-assisted Fenton treatment and mild alkali treatment on their physicochemical characteristics and biological functions

Buckwheat sprouts are rich in pectic polysaccharides, which possess numerous health-improving benefits. However, the precise structure–activity relationship of pectic polysaccharides from Tartary buckwheat sprouts (TP) is still scant, which ultimately restricts their applications in the food industry. Hence, both ultrasound-assisted Fenton treatment (UAFT) and mild alkali treatment (MATT) were utilized for the modification of TP, and then the effects of physicochemical characteristics of original and modified TPs on their bioactivities were assessed. Our findings reveled that the UAFT treatment could precisely reduce TP’s molecular weight, with the levels decreased from 8.191 × 104 Da to 0.957 × 104 Da. Meanwhile, the MATT treatment could precisely reduce TP’s esterification degree, with the values decreased from 28.04 % to 4.72 %. Nevertheless, both UAFT and MATT treatments had limited effects on the backbone and branched chain of TP. Moreover, our findings unveiled that the UAFT treatment could notably promote TP’s antioxidant, antiglycation, and immunostimulatory effects, while remarkedly reduce TP’s anti-hyperlipidemic effect, which were probably owing to that the UAFT treatment obviously reduced TP’s molecular weight. Additionally, the MATT treatment could also promote TP’s immunostimulatory effect, which was probably attributed to that the MATT treatment significantly decreased TP’s esterification degree. Interestingly, the MATT treatment could regulate TP’s antioxidant and antiglycation effects, which was probably attributed to that the MATT treatment simultaneously reduced its esterification degree and bound phenolics. Our findings are conducive to understanding TP’s structure–activity relationship, and can afford a scientific theoretical basis for the development of functional or healthy products based on TPs. Besides, the UAFT treatment can be a promising approach for the modification of TP to improve its biological functions.

Differential effects of enzymatically modified Ougan (Citrus Suavissima Hort. ex Tanaka) peel pectins extracted with different methods on inhibiting the proliferation of Hela cells

Previous studies have shown that modified citrus pectin (MCP) is an anti-tumor material of food grade. In this study, two enzymatically modified Ougan (Citrus Suavissima Hort. ex Tanaka) peel pectins (EMP1 and EMP2, the ones extracted by alkali and enzymatic methods) were used to investigate their differential effects on viability and physiology of Hela cells. The results showed that EMP1 and EMP2 had 88.00 % and 81.01 % galacturonic acid, 21.31 % and 20.25 % esterification degree, 10,417 g/mol and 6416 g/mol molecular weight (Mw), 82.86 % and 50.62 % RG-I, and 8.91 % and 15.70 % HG, respectively. EMP2 had higher intensities of absorption peaks than EMP1. They were irregularly shaped, with more holes on EMP1 but more wrinkles on EMP2. Both could inhibit the growth, proliferation, migration, and invasion of HeLa cells in a concentration-dependent manner, with better efficiency in EMP2. Meanwhile, EMP2 was more efficient than EMP1 in blocking the cell cycle in S phase, resulting in apoptosis. In conclusion, the variations caused by extraction resulted in differences in anti-tumor activity of MCP and EMP2 with lower Mw and higher HG exhibited better anti-tumor effects. This study would provide an experimental basis and reference for the research and development of anti-tumor supplements from citrus pectin.

Fabrication of hydrogen-bonded crosslinked hydrogel vitrimer with enhanced self-healing and printability via K+ induced low methyl apple pectin

Low methyl pectin, conventionally extruded as sols and shaped through Ca2+ post-curing, face complexity and high production costs, limiting their application in 3D printing. We developed apple pectin (AP) vitrimer inks with shear-thinning behavior at elevated temperatures and self-supporting properties at low ones, via pectin methyl esterase (PME) modification and K+ induction, aiming to facilitate simpler extrusion 3D printing. PME-modified AP (PME-AP) exhibits a higher affinity for K+ compared to AP, attributed to an 8.76 % reduction in the degree of methyl esterification and a 9.72 % increase in the degree of blockiness. Consequently, 1 % PME-AP forms a robust hydrogel vitrimer characterized by a hardness of 121.33 g and a water holding capacity of 99.50 % at 150 mM K+, a 68 % reduction in K+ concentration requirement over AP gels. Through electrostatic shielding, K+ induces hydrogen-bonded crosslinked vitrimers with stress relaxation within 53 s at 80 °C and self-healing properties with minimal texture reduction (~2 g). These characteristics suggest that the hydrogen bond crosslinked vitrimer network can dynamically reorganize in response to temperature variations, making PME-AP gel ideal for 3D printing applications. This study establishes the groundwork for cost-efficient AP-based extrusion 3D printing.

Potentials of Mahachanok mango peel pectin in modulating glycaemic index in simulated in vitro carbohydrate digestion of meat product

Pectin derived from mango peel biomass offers a noteworthy alternative to starch in food products, potentially assisting in controlling hyperglycaemia by impacting starch digestion. Consequently, this study evaluates the potential of Mahachanok mango peel (MHMP) pectin in glycaemic index (GI) reduction of meat products using simulated in vitro carbohydrate digestion. The physicochemical characteristics of MHMP pectin (MHMPP) were assessed using both FTIR and titration techniques, with microarray polymer profiling employed to analyse the glycan profile. In vitro simulations of carbohydrate digestion were carried out to assess its efficacy. Additionally, meatballs fortified with MHMPP were formulated, and the glycaemic index of the resultant products was ascertained. Microarray polymer profiling revealed distinct glycans in different fractions, including galactose, xyloglucan, and glycoprotein. Microwave extraction of pectin yielded 19.04 % MHMPP content with specific characteristics: L* (58.04), a* (12.80), b* (23.50), 6.81 % moisture content, and 78.63 % solubility. The degree of esterification at 55.73 %, an equivalent weight of 789.26 mg/moL, and a methoxyl content of 8.39 %, evidently identified MHMPP as high-methoxyl pectin. In a simulated system of MHMPP, content correlates with reduced digestion, supported by lowered values across the hydrolysis index (HI), rapidly available glucose (RAG), slowly available glucose (SAG), and expected glycaemic index (eGI). Higher MHMPP levels consistently exhibit a decreased impact on these digestive factors. In a simulated meat product system, increased MHMPP content corresponded to slower digestion rates, indicating its potential to retard digestion, as supported by HI, RAG, SAG, and eGI. The supplementation of 25 % pectin to meatballs is the most successful treatment, as it results in eGI, RAG, and SAG values of 8.71 (mg/gsample), 6.65 (mg/gsample), and 1.85 (mg/gsample), respectively. This study highlights the advantage of MHMP-derived dietary fibre in product development from industrial byproducts, aligning with sustainable development goals by reducing reliance on non-renewable materials.

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.

Microwave-assisted acid extraction of high-methoxyl kinnow (Citrus reticulata) peels pectin: Process, techno-functionality, characterization and life cycle assessment

The present study assessed the efficacy of kinnow peel pectin-acetic acid extraction using microwave heating at 110 °C, pH 2.2 for 10 min with a 1:2 ratio supernatant to ethanol for higher yield. The kinnow peel was freeze dried and grinded to fine powder for pectin extraction. The microwave extracted (ME) kinnow pectin showed 833 mg equivalent weight, 7.44 % methoxyl content, 66.67 % degree of esterification, 63.15 % galacturonic acid content and evinced higher purity than commercial citrus pectin. ME kinnow pectin exhibited shear thinning behaviour while higher apparent viscosity (Pa. s) at 20 % concentration. The ME kinnow pectin showed characteristic functional groups and a less crystalline structure as deduced from FT-IR, SEM and XRD respectively, and a higher thermal decomposition analysed from TGA. Further, life cycle assessment (LCA) predicted that the ethanol and acetic acid were major contributors toward climate change in this study. ME kinnow pectin has the potential to be used as a commercial pectin in various food applications.

Tunning the hydrophobic performance and thermal stability of pectin film by acetic anhydride esterification

Pectin, a polysaccharide found in plant cell walls, is characterized by a high abundance of hydroxyl groups and carboxylic acid groups, which results in a strong affinity for water and limits its suitability as a film material. This study aimed to modulate the esterification degree of PEC films by adjusting the concentration of acetic anhydride, and assess the impact of acetic anhydride esterification modification on the properties of the resultant PEC films. The results demonstrated successful grafting of acetic anhydride onto the galacturonic acid ring in the PEC molecule through the esterification process. The hydrophobicity, thermal stability, barrier properties, and mechanical properties of the esterified PEC films were investigated. Among the various concentrations tested, the E-PEC-0.25 film exhibited the highest contact angle of 103.46° and tensile strength of 33.44 MPa, showcasing optimal performance. The E-PEC-0.1 film achieved the highest esterification degree of 0.94 and elongation at a break of 21.11 %. It also exhibited the transparency of 11.66 and the lowest water vapor transmission rate of 0.56 g·mm/(m2·h·kpa). Additionally, TGA and DSC tests revealed enhanced thermal stability of the esterification-prepared films. These findings highlight the potential of acetic anhydride tuning as a promising strategy for optimizing pectin film production.

Effect of different pectin sources and structures on the stability of cyanidin-3-O-glucoside (C3G)

The physicochemical properties of cyanidin-3-O-glucoside (C3G) were investigated after binding with pectin from different sources (apple and peach) and fractions (water-soluble fraction (WSF), chelator soluble fraction (CSF) and sodium carbonate soluble fraction (NSF)). Apple WSF and peach CSF were high esterification degree pectin (DE) (63.23% and 55.66%). CSF of both AP and PP was abundant in HG and exhibited a much more linear structure than WSF and NSF. The maximum binding percentage was obtained at pH 2.0 for apple pectin (AP) (46%–50%) and at pH 3.5 for peach pectin (PP) (50%–54%). Binding with both pectins increased the color stability of C3G at pH 2.0. High DE pectin increased C3G light stability by reducing the degradation rate (0.03 h−1) compared to C3G alone (0.05 h−1). All the pectins reduced the thermal degradation rate of C3G, thus exhibiting a protective effect. A negative correlation was found between the relative RG I area and the particle size of the pectin-C3G complexes. Pectin played a leading role in the ζ-potential change.

Optimization of subcritical water extraction for pectin extraction from cocoa pod husks using the response surface methodology

This study optimized subcritical water extraction (SWE) conditions to maximize pectin yield from cocoa pod husk (CPH) and compared the characteristics of CPH pectin extracted through SWE with those of CPH pectin obtained through conventional extraction (CE) with citric acid. The Box–Behnken experimental design was employed to optimize SWE and examine the influence of process parameters, including temperature (100 °C–120 °C), extraction time (10–30 min), and solid:liquid ratio (SLR) (1:30–2:30 g/mL), on pectin yield. The maximum pectin yield of 6.58% was obtained under the optimal extraction conditions of 120 °C for 10 min with 1:15 g/mL SLR and closely corresponded with the predicted value of 7.29%. Compared with CE, SWE generated a higher yield and resulted in a higher degree of esterification, methoxyl content, and anhydrouronic acid value but a lower equivalent weight. The extracted pectin was pure, had low-methoxyl content, and similar melting and degradation temperatures.

The influence of the pectin structure on the properties of hydrogel dressings doped with octenidine-containing antiseptic

This article presents a method for producing hydrogel dressings using high methylated pectin from apples or citrus, doped with the antiseptic agent, octenidine dihydrochloride. Octenidine was incorporated in-situ during the polymer crosslinking. The pectins were characterized by their varying molecular weight characteristics, monosaccharide composition, and degree of esterification (DE). The study assessed the feasibility of producing biologically active hydrogels with pectin and delved into how the polymer's characteristics affect the properties of the resulting dressings. The structure evaluation of hydrogel materials showed interactions between individual components of the system and their dependence on the type of used pectin. Both the antimicrobial properties and cytotoxicity of the dressings were evaluated. The results suggest that the primary determinants of the functional attributes of the hydrogels are the molecular weight characteristics and the DE of the pectin. As these values rise, there is an increase in polymer-polymer interactions, overshadowing polymer-additive interactions. This intensification strengthens the mechanical and thermal stability of the hydrogels and enhances the release of active components into the surrounding environment. Biological evaluations demonstrated the ability of octenidine to be released from the dressings and effectively inhibit the growth of microbial pathogens.

Optimizing the microwave-assisted hydrothermal extraction of pectin from tangerine by-product and its physicochemical, structural, and functional properties

Microwave-assisted hydrothermal extraction (MAHE) was optimized using a Box-Behnken design (BBD) of the response surface methodology (RSM) for optimal recovery of pectin from tangerine peel (TPP). The effects of three factors (pH, irradiation time and temperature) on extraction yield (EY), galacturonic acid content (GAC) and degree of esterification (DE) of pectin were investigated. The optimal extraction conditions were as follows: pH 1.7, irradiation time 12 min and temperature 109 °C. Under these conditions, the EY, GAC and DE were 30.4, 72.3 and 45.2%, respectively. The low methoxyl content of MHAE (45.2%) compared to CE is confirmed by the 1H NMR and FTIR spectra, and the emulsifying activity is 57.65% and 50.56% for CE and MHAE, respectively. The total phenolic content (TPC) of pectin produced using MAHE is 41.2 mg GAE/g, thus indicating higher antioxidant properties compared to pectin produced with CE, which had a TPC of 38.4 mg GAE/g. In addition, the X-ray diffraction (XRD) and surface morphological analysis (SEM) results showed that TPP had a rough surface and crystalline structure. Overall, our findings show that TTP from MAHE can be used as a natural antioxidant ingredient in the functional food and pharmaceutical industries.

Green preparation of cellulose nanocrystals and nanofibers by ball milling assisted citric acid hydrolysis

In order to solve the drawbacks of carboxylated cellulose nanocrystals (CNCs) prepared by critic acid (CA) hydrolysis method, such as low yield and low esterification degree, herein, ball milling assisted CA hydrolysis method was applied to obtain carboxylated CNCs and cellulose nanofibers (CNFs) with fine and uniform size, high yield and carboxyl content, good crystallinity, and good thermal stability. It was discovered that the diameter of CNCs and CNFs were decreased and the size uniformity was improved. The yield of CNCs was obviously improved to 39.8 % due to the promoted esterification reaction, which was 3.3 times of that without ball milling. Moreover, the carboxyl group content of CNCs and CNFs were improved to a maximum of 0.52 and 0.48 mmol/g, respectively. As ball milling progressing, more amorphous regions were destroyed and cellulose bundles were dissociated, resulting in CNCs and CNFs with high crystallinity. The thermal decomposition temperature of CNCs and CNFs were ranged from 317 to 331℃, which was higher than that had reported. This work provided an effective route for carboxylated CNCs with good yield, esterification degree and other performance, which was beneficial for the subsequent applications in the field of biomaterials.

Pectic substances from babassu mesocarp flour: extraction and characterization

The Amazon region contains distinct fruit species, such as the babassu, which are still little known, but may have great scientific and technological potential. Oil and flour are extracted from babassu fruits. The oil is used industrially and is listed in the Codex Alimentarius as a commodity. Babassu mesocarp flour is consumed in the Amazon region but is little known technologically. For this purpose, the present work aimed to use babassu mesocarp flour to extract pectin, an important additive for the food industry. The yield was quantified and the titration quality of the extracted material was evaluated. In order to determine the best extraction conditions, were tested different extraction time (30, 60 and 90 min) and concentration of citric acid (3, 4.5 and 6%) at constant temperature (90°C). The best results of quality were found for Experiment 5. Yield was approximately 25% when operating conditions were 60 min and 4.5% citric acid. Titrimetric quality of pectic material extracted in these conditions (experiment 5) was better than the others, with highest concentration of galacturonic acids (50%) and the highest degree of esterification (71.4%). Results of this study showed that mesocarp of a fruit from the amazon region (babassu) proved to be a great alternative source for pectic substances extraction. Technological quality of its pectic substances still needs to be better evaluated.

Structural properties and biological effects of pectic polysaccharides extracted from Tartary buckwheat sprouts by high pressure-assisted deep eutectic solvent extraction

Tartary buckwheat sprout is commonly consumed as salads and healthy vegetables, which is rich in pectic polysaccharides. Nevertheless, the knowledge about pectic polysaccharides extracted from Tartary buckwheat sprouts (TBSP) are still limited. To facilitate the potential applications of TBSP as fortified ingredients or healthy foods, the impacts of conventional hot water extraction (CHW), deep eutectic solvent (DES)-assisted extraction (DEE), and high pressure-assisted DES extraction (HPDEE) on their structural and biological properties were evaluated. Compared with the CHW method, our findings revealed that both DEE and HPDEE methods could obviously promoted the yields of TBSP and regulated their structural properties, resulting in the improvement of their biological functions. Especially, the HPDEE method could obviously decreased the molecular mass, apparent viscosity, and esterification degree of TBSP, while notably increased the uronic acids and bound flavonoids. Indeed, the HPDEE method could remarkedly enhance the antioxidant, anti-glycosylation, and immunostimulatory activities of TBSP probably via reducing its molecular mass and degree of esterification, and increasing its free uronic acids and bound flavonoids. These findings reveal that the HPDEE method has good potentials for selectively extracting distinctive TBSP with superior biological functions.

Extraction and characterization of pectin from coffee (Coffea arabica L.) pulp obtained from four different coffee producing regions

The pectin was extracted using H2SO4, HNO3, and HCl from the pulp of four coffee varieties (Harar, Sidama, Jimma, and Guji) collected from different regions of Ethiopia. The effect of extraction temperature, time, solid-to-liquid ratio, types of acid and coffee varieties on the physiochemical properties and yield of pectin were studied. A maximum pectin yield, which was 12.7 %, was obtained from Harar coffee pulp treated with H2SO4. The equivalent weight of the extracted pectin varied from 1111 to 1667 g/mol. The methoxyl contents of the extracted pectin ranged from 4.23 to 7.13 %. The degrees of esterification and anhydrouronic acid of the pectin ranged from 53 to 68.5 % and 35.5 to 68.8 %, respectively. The results show the yield and physiochemical properties of the coffee pulp pectin depend on extraction parameters, acid types, and coffee varieties. Moreover, the pectin extracted from coffee pulp showed strong gelling properties.

Structure characterization and gelling properties of RG-I-enriched pectins extracted from citrus peels using four different methods

To facilitate the application of rhamnogalacturonan-I (RG-I)-enriched pectins (RGPs) as novel, healthy, and gelling food additives, this study compared the structural characteristics and gelling properties of RGPs extracted from citrus peel via four methods (alkali: AK, high-temperature/pressure: TP, citric acid: CA, and enzyme-assisted: EA extractions). AK and CA yielded pectins with the highest RG-I proportions (54.8 % and 51.9 %, respectively) by disrupting the homogalacturonan region; TP and EA increased the RG-I proportions by ~10 %. Among the four methods, AK induced the lowest degree of esterification (DE) (6.7 %) and longer side chains that form strong entanglement, contributing to its highest gel hardness. The relatively low DE (18.5 %) of CA RGP facilitated stable gel formation. Notably, its highly branched RG-I region afforded more intramolecular hydrophobic interactions, making a more highly cross-linked gel network of better gel resilience. In contrast, TP induced the highest DE (57 %) and curved molecular chains; it inhibited Ca2+ binding, entanglement, and intramolecular hydrophobic interactions, and thus no gel formed. EA RGP was associated with the lowest molecular size, rendering it more difficult for Ca2+ to form links, which resulted no gel. These findings offer insights into the relationship among the extraction methods, molecular structures, and gelling properties of RGPs.