From Nature to Science: A Review of the Applications of Pectin-Based Hydrogels

Abstract

Pectin is widely used in different areas like biomedical, pharmaceutical, food, and environmental industries thanks to its gelling properties. Pectin hydrogels are of great interest because of their wide biomedical applications in drug delivery, tissue engineering, wound healing, the food industry, agriculture, and cosmetic products because of their biocompatibility, biodegradability, and non-toxic nature. This review provides an understanding of pectin-based hydrogels and their applications in various industrial areas. In addition, an overview of emerging technologies and recent applications of pectin hydrogels is provided, including the controlled and targeted release of bioactive compounds or drugs. They are used as a scaffold for cell growth, as a wound dressing to promote healing, as a fat replacer in food, and as a texturizer in skin-care products. It also serves as a coating for seeds to improve their germination and growth. This paper also identifies knowledge gaps and future research direction for optimizing pectin hydrogels.

1. Introduction

The term hydrogel describes a three-dimensional network structure obtained from polymers capable of absorbing and retaining water owing to the presence of hydrophilic groups or domains along the polymeric chain. When crosslinking, these chains can form a complex 3D hollow structure with air space. After hydration in an aqueous environment, these spaces are filled with water, resulting in a unique water-holding capacity and absorbance. Hydrogel classification depends on physical properties, nature of swelling, method of preparation, ionic charges, sources, rate of biodegradation, and crosslinking nature [1,2]. Hydrogels can be classified according to their composition as homopolymers, copolymers, or interpenetrating networks. This refers to polymeric networks derived from a single type of monomer, two different monomers where at least one has hydrophilic properties that are necessary for optimum swelling of the hydrogel. Or mixtures of two polymers that are crosslinked and formed during two parallel and simultaneous reactions according to different mechanisms [2,3]. The use of polymers in hydrogel manufacturing depends on the purpose of the material. Currently, most of the hydrogels are made with synthetic polymers such as polyacrylamide [4], polyethylene glycol [5], and polyvinyl alcohol [6] because of their mechanical, physical and chemical properties. However, their lack of biocompatibility and slower degradation rates are some major concerns due to the release of potentially harmful metabolites. Therefore, biopolymers such as polysaccharides are promising materials for developing hydrogels because they uniquely combine biocompatibility, biodegradability, abundance, and sustainability with tailored chemical and mechanical properties. This allows for the production of safe, versatile, application-specific hydrogels for advanced use in medicine, food, and environmental applications [7,8,9,10].

Natural hydrogels are obtained from natural-based sources such as collagen [11], and gelatin [12], and polysaccharides such as cellulose [13], agarose [14], alginate [15], chitosan [16], and pectin [17]. Pectin is a natural polysaccharide primarily found in the cell walls of fruits and vegetables. Chemically, it is constituted by galacturonic acid units and can form gels in the presence of sugar and acid, making it widely used for various applications. Contrary to other polysaccharides or natural-based materials, pectin and its derivatives are characterized by its biocompatibility, biodegradability, non-toxic nature, low-cost production, versatile functionalization, controlled release capacity, and sustainability. When utilized for the development of hydrogels, pectin can be implemented to obtain structures with higher durability, improved strength, and high-water absorption capacity [1,3,18]. Still, when integrated with additional materials, it can also occur in the obtention of hybrid hydrogels with variable physical, chemical, and mechanical properties [3].

Specifically, pectin hydrogels are formed by connecting two pectin molecules to form a macromolecular network joined via junction zones formed by sections from different polymer molecules. These are linked and stabilized by hydrogen bonding between the carboxyl and secondary alcohol groups and hydrophobic interactions between methyl esters. Depending on the degree of methyl esterification, pectin is classified as low-methoxyl pectin (LMP; 20–49%) or high-methoxyl pectin (HMP; 60–75%). This property influences gelation mechanism: high-methoxyl pectin can form gels by a cold gelation mechanism, and low-methoxyl pectin can form gels by ionotropic gelation. Pectin is a biopolymer derived from the cell walls of various plants, fruits, and vegetables. It is composed of a galacturonic acid backbone, in which its carboxyl groups can be esterified with methyl or acetyl groups. A variety of neutral sugar molecules, such as arabinose, galactose, and rhamnose, can also be added to the chain.

Despite the growing interest in pectin hydrogels, existing reviews often focus on either extraction methods or a specific application without integrating interdisciplinary advances across multiple sectors. The aim of this review is to provide a synthesis of current knowledge on pectin-based hydrogels, including structural features, gelling mechanisms, preparation strategies, and applications such as in drug delivery, tissue engineering, wound healing, food, agriculture, and environmental remediation. By highlighting recent innovations and identifying existing research gaps such as the need for improved mechanical properties, scalability of production, and regulatory considerations, this review offers a novel and updated perspective that may guide future research and applications.

2. Methodology

To ensure a rigorous review, a structured bibliographic search was conducted. The databases consulted were PubMed, Scopus, Web of Science, and Google Scholar, where the main keywords were used in different combinations: pectin hydrogels, pectin-based biomaterials, crosslinking of polysaccharides, drug delivery, wound healing, tissue engineering, and biomedical applications. Peer-reviewed articles published between 2020 and 2025 were included, although earlier seminal works were added when relevant. Inclusion criteria were as follows: (i) original research articles or reviews addressing pectin hydrogel properties and/or applications; (ii) studies written in English; and (iii) availability of full text. Exclusion criteria included (i) conference abstracts without peer review; (ii) studies unrelated to pectin or not addressing hydrogel formulations; and (iii) duplicated information already covered by more recent reviews.

3. General Features About Pectin

Historically, pectin was identified in 1825 when Dr. Henri Braconnot extracted it from apple pomace utilizing acidified experimental conditions. Originally, pectin was designated as pectic acid, which was associated with the Greek word πηχτες, meaning coagulated material [19]. Unlike other plant structural components, pectin executes significant biological properties as it can aid the growth and development of plants by upregulating their water retention capacity, defense mechanisms towards potential phytopathogens, and nutrient transport pathways.

Biosynthetically, pectin and its derivatives are produced in the cisternae from the Golgi apparatus through the synergistic activity of acetyltransferases, glycosyltransferases, and methyltransferases, as well as uridine diphosphate-sugar pyrophosphorylases (UDP-sugar pyrophosphorylases), and nucleotide sugar transporters [20]. The transport of pectin and its derivatives to cell wall components is achieved by packaging into vesicles and exocytosis phenomena. The biosynthesis of pectin is illustrated in Figure 1A. Once incorporated into the cell wall structure, pectin acts as the primary adhesive matrix by covalently linking cellulose fibrils to other polymers (Figure 1B), to help in maintaining the hardness pressure of cell walls, thus determining the growth and extension of plants [21].

Chemically, pectin is constituted by a backbone of α-D-galacturonic acid residues linked by α-(1→4) glycosidic bonds (Figure 1C). Compared to other natural components, pectin exhibits variable degrees of methylation and hence can be classified as high- or low-methylated pectin. The former category of pectin derivatives is characterized by having more than half of their carboxyl groups esterified, whereas the latter contains less than half esterified carboxyl groups [22,23]. Given the variability in the degree of esterification, pectin is also constituted by neutral sugars such as arabinose, rhamnose, galactose, and xylose.

Figure 1. (A) Pectin is polymerized in the cis-Golgi, methyl esterified in the medial-Golgi, while substitution with side chains occurs in the trans-Golgi cisternae. (B) The concentration of pectin decreases gradually from the primary plant cell wall towards the plasma membrane, leading to the highest concentration of pectin located in the middle lamella [24]. (C) Pectin structural domains include homogalacturonan (HG, 65%), which consists of D-galacturonic acid (GalA) chains that may be methyl esterified or acetylated. Along this backbone, substitutions generate distinct domains, including xylogalacturonan (XGA), and arabinogalactan-rich regions (AG) with neutral sugars such as L-arabinose and D-galactose. The “hairy” regions comprise rhamnogalacturonan I (RG-I) with L-rhamnose and GalA units plus neutral sugar side chains, and rhamnogalacturonan II (RG-II), a highly branched domain built on an HG backbone and containing diverse rare sugars [25]. Created in BioRender. Sánchez, A. (2025) https://BioRender.com/ughjtcg.

Figure 1. (A) Pectin is polymerized in the cis-Golgi, methyl esterified in the medial-Golgi, while substitution with side chains occurs in the trans-Golgi cisternae. (B) The concentration of pectin decreases gradually from the primary plant cell wall towards the plasma membrane, leading to the highest concentration of pectin located in the middle lamella [24]. (C) Pectin structural domains include homogalacturonan (HG, 65%), which consists of D-galacturonic acid (GalA) chains that may be methyl esterified or acetylated. Along this backbone, substitutions generate distinct domains, including xylogalacturonan (XGA), and arabinogalactan-rich regions (AG) with neutral sugars such as L-arabinose and D-galactose. The “hairy” regions comprise rhamnogalacturonan I (RG-I) with L-rhamnose and GalA units plus neutral sugar side chains, and rhamnogalacturonan II (RG-II), a highly branched domain built on an HG backbone and containing diverse rare sugars [25]. Created in BioRender. Sánchez, A. (2025) https://BioRender.com/ughjtcg.

The primary sources of pectin are citrus fruits (e.g., oranges, lemons, and grapefruits), apples, berries, carrots, and beetroot [26]. Factors influencing pectin content in such sources include soil type, climate, agricultural practices, cultivar species, storage conditions, and extraction and processing techniques. As shown in Table 1, the extraction of pectin can be performed by implementing laboratory techniques frequently related to the obtention of valuable natural products based on the hydrolysis and isolation of pectin from plant tissues into a solvent; some of these approaches encompass hot water, acid-mediated, enzymatic, alkaline, and microwave-assisted extraction (MAE) [27]. Due to its versatility, simplicity, safety, and cost-effectiveness, hot water extraction—alone or in combination with electromagnetic fields—is widely employed to obtain pectin from dragon fruit peels [28], lemon peel powder [29], or mandarin peels [30]. MAE is another frequently considered approach to extracting pectin from coffee fruit [31], sugar beet pulp [32], and banana peels [33]. The use of other approaches is also widely documented; however, recent scientific evidence suggests that their use is related to low extraction yields and time-consuming processes. Therefore, pectin content, its composition, and functional properties are strongly dependent on the pectin source, development stage of plants, and extraction conditions [34], and a complete characterization will be useful to understand the possible applications [35].

Table 1. Reported pectin extraction methods from various sources and their main outcomes.

Source	Extraction Method	Outcomes	Reference
Riang husk	Ultrasound-assisted using DESs	The combination Be: CA (1:5) proved to be the most effective for optimizing pectin yield from Riang husks. The optimal experimental settings were recorded at an ultrasonic power of 28.11 W, L/S ratio of 40 mL/g, and 60 min of extraction time. Inhibition of cellular damage upon exposure to H2O2 in HaCaT cells. Antioxidant activity at 0.26 ± 0.02 mmol Trolox equivalents/g.	[36]
GFP	Maceration	Citric acid-based hydrolysis conducted at 70–80 °C and a pH of 2–3 resulted in a 1.25-fold increase in the yield of HMP. FTIR analysis revealed 17.6% methoxyl content among samples. SEM-EDX evaluation evidences the high abundance of oxygen, potassium, and calcium. The 60–75% degree of esterification enabled the manufacture of jellies with improved color, texture, and odor.	[37]
Carrot pomace	Enzymatic	Enzyme-based extraction comprehended the activity of cellulase and hemicellulose. When combined with heat treatment, the implemented enzymes promoted the obtention of high pectin yields with improved purity, but lower molar mass. The implemented extraction process resulted in improved monosaccharide ratios.	[38]
Dillenia indica	Microwave-assisted	The optimized parameters were identified at 1:23.66 solid–solvent, 400 W microwave power, and 7 min of extraction time. The extracted pectin exhibited 9.61 ± 0.31%, 73.56 ± 1.86%, 74.15 ± 0.28%, and 1.16 ± 0.16% of methoxyl value, anhydrouronic acid content, degree of esterification, and protein content, respectively. The analyzed pectin displayed endothermic and exothermic behavior. The moisture content and as content were 7.23 ± 0.25% and 2.23 ± 0.25%, respectively.	[39]
Dried pomace	Microwave-assisted high-pressure CO2/H2O	The ideal conditions for extracting pectin consisted of 130 °C of temperature, 2.0 min of extraction time, and 22.5:1 mL/g of liquid-to-solid ratio. The implemented extraction procedure was 28.4%, saving 97% time when compared with conventional acid hydrolysis. The extracted pectin exhibited high purity when compared with commercial standards according to FTIR analysis. The obtained pectin displayed high emulsifying activity (61.67%) and upregulated solubility (87.36%).	[40]
Banana peels	Soxhlet	The optimal conditions for pectin extraction were at 80 °C and pH 4.5, resulting in 13.06% extraction yield. The determined compositional features consisted of 39.23% galacturonic acid content, 70.70% degree of esterification, and 11.50% methoxyl content. The extracted pectin, in combination with ascorbic acid, was ideal for the development of coatings for banana storage. Stored bananas with pectin-based coatings exhibited improved color retention and downregulated polyphenol-oxidase activity.	[41]

Abbreviations: DESs, deep eutectic solvents; Be, betaine; CA, citric acid; L/S, liquid/solid; H₂O₂, hydrogen peroxide; HaCaT, high sensitivity of human epidermal keratinocytes; GFP, grapefruit; HMP, high methoxy pectin; FTIR, Fourier Transform Infrared spectroscopy; SEM, scanning electron microscopy; EDX, energy dispersive X-ray spectroscopy.

Table 1. Reported pectin extraction methods from various sources and their main outcomes.

Source	Extraction Method	Outcomes	Reference
Riang husk	Ultrasound-assisted using DESs	The combination Be: CA (1:5) proved to be the most effective for optimizing pectin yield from Riang husks. The optimal experimental settings were recorded at an ultrasonic power of 28.11 W, L/S ratio of 40 mL/g, and 60 min of extraction time. Inhibition of cellular damage upon exposure to H2O2 in HaCaT cells. Antioxidant activity at 0.26 ± 0.02 mmol Trolox equivalents/g.	[36]
GFP	Maceration	Citric acid-based hydrolysis conducted at 70–80 °C and a pH of 2–3 resulted in a 1.25-fold increase in the yield of HMP. FTIR analysis revealed 17.6% methoxyl content among samples. SEM-EDX evaluation evidences the high abundance of oxygen, potassium, and calcium. The 60–75% degree of esterification enabled the manufacture of jellies with improved color, texture, and odor.	[37]
Carrot pomace	Enzymatic	Enzyme-based extraction comprehended the activity of cellulase and hemicellulose. When combined with heat treatment, the implemented enzymes promoted the obtention of high pectin yields with improved purity, but lower molar mass. The implemented extraction process resulted in improved monosaccharide ratios.	[38]
Dillenia indica	Microwave-assisted	The optimized parameters were identified at 1:23.66 solid–solvent, 400 W microwave power, and 7 min of extraction time. The extracted pectin exhibited 9.61 ± 0.31%, 73.56 ± 1.86%, 74.15 ± 0.28%, and 1.16 ± 0.16% of methoxyl value, anhydrouronic acid content, degree of esterification, and protein content, respectively. The analyzed pectin displayed endothermic and exothermic behavior. The moisture content and as content were 7.23 ± 0.25% and 2.23 ± 0.25%, respectively.	[39]
Dried pomace	Microwave-assisted high-pressure CO2/H2O	The ideal conditions for extracting pectin consisted of 130 °C of temperature, 2.0 min of extraction time, and 22.5:1 mL/g of liquid-to-solid ratio. The implemented extraction procedure was 28.4%, saving 97% time when compared with conventional acid hydrolysis. The extracted pectin exhibited high purity when compared with commercial standards according to FTIR analysis. The obtained pectin displayed high emulsifying activity (61.67%) and upregulated solubility (87.36%).	[40]
Banana peels	Soxhlet	The optimal conditions for pectin extraction were at 80 °C and pH 4.5, resulting in 13.06% extraction yield. The determined compositional features consisted of 39.23% galacturonic acid content, 70.70% degree of esterification, and 11.50% methoxyl content. The extracted pectin, in combination with ascorbic acid, was ideal for the development of coatings for banana storage. Stored bananas with pectin-based coatings exhibited improved color retention and downregulated polyphenol-oxidase activity.	[41]

Abbreviations: DESs, deep eutectic solvents; Be, betaine; CA, citric acid; L/S, liquid/solid; H₂O₂, hydrogen peroxide; HaCaT, high sensitivity of human epidermal keratinocytes; GFP, grapefruit; HMP, high methoxy pectin; FTIR, Fourier Transform Infrared spectroscopy; SEM, scanning electron microscopy; EDX, energy dispersive X-ray spectroscopy.

4. Gelling Mechanisms

When gels are formed, water can be immobilized when junction zones in the smooth regions of pectin molecules form a three-dimensional network via specific intermolecular bonds. Both HMP, and LMP form gels; however, they are formed via different mechanisms (Figure 2). HMP forms a gel in the presence of elevated concentrations of co-solutes such as sucrose at low pH. LMP forms a gel in the presence of calcium by forming a junction zone commonly known as “egg-box” in which calcium causes the cross-linking of two stretches of polygaracturonic acid chains [42,43]. Then, a polymer that formed no junction zones would remain in the solution, and one capable of forming junctions through its length would be insoluble. A junction zone is formed by segments of polymers that are attached and stabilized by hydrogen bonding between the carboxyl and secondary alcohol groups, and hydrophobic interactions between methyl esters. Gelation commences once the pectin powder is in contact with water and becomes hydrated and dissolved, often under heating conditions. Pectin solubility in aqueous media depends on multiple parameters, the main ones being the counterionic nature, ionic strength, pH, and temperature [42]. Then, as it was mentioned, depending on whether the pectin is of HM or LM type, the gel is formed by different mechanisms, ones that are described below.

Dissolved high methoxylated pectin can form a gel in an acidic medium (pH < 3.5) in the presence of a cosolute, typically sucrose, at a concentration above 55% (w/w), these gels are often referred to as “acid gels.” The high sugar concentration resulted in lower water activity and improved the hydrophobic interactions between the methoxyl groups. A low pH is required to reduce the dissociation of the carboxyl groups and diminish electrostatic repulsion. These non-dissociated carboxyl groups can form hydrogen bonds with the secondary alcohol groups. The cold gelation of HM pectin is a 2-step process. Pectin powder was dissolved in water at temperatures above 50 °C, promoting hydrophobic interactions among the non-polar methoxyl and ester groups of the polymer chain. The junction zones are stabilized by these interactions combined with hydrogen bonds. The hydrophobic effects arise from the undesirable interactions between water and the methoxyl groups of pectin molecules, which are forced to join to reduce the contact area with water thus reducing the entropy. Upon cooling the pectin solution to room temperature, hydrophobic interactions are disrupted and replaced by hydrogen bonds involving the carboxyl (–COOH) groups of the pectin chain and the hydroxyl (–OH) groups of adjacent molecules [44,45,46].

Figure 2. Pectin is classified depending on the degree of methyl-esterification (DM) as either high-methoxyl (HM; DM > 50%) or low-methoxyl (LM; DM < 50%) type. Gelation in pectin commences once the particles are swollen in water. Subsequently, pectin is hydrated and dissolved under heating conditions, then, depending on whether the pectin is DM or LM type, the gel is formed by following either hydrogen bonding or ionotropic gelation (mainly Ca²⁺) mechanisms [47]. Created in BioRender. Sánchez, A. (2025) https://BioRender.com/ughjtcg.

Figure 2. Pectin is classified depending on the degree of methyl-esterification (DM) as either high-methoxyl (HM; DM > 50%) or low-methoxyl (LM; DM < 50%) type. Gelation in pectin commences once the particles are swollen in water. Subsequently, pectin is hydrated and dissolved under heating conditions, then, depending on whether the pectin is DM or LM type, the gel is formed by following either hydrogen bonding or ionotropic gelation (mainly Ca²⁺) mechanisms [47]. Created in BioRender. Sánchez, A. (2025) https://BioRender.com/ughjtcg.

For low methoxyl pectins, gelation results from specific non-covalent ionic interactions between blocks of galacturonic acid residues of the pectin backbone and divalent ions such as calcium. To achieve gelation, the required pH range is 2.0 to 6.0, which is larger than that required for HMP; however, sugar addition is not necessary. The affinity of pectin chains towards calcium increases with the degree of esterification (DE) leasing and with an increased polymer concentration. In addition to the influence of the charge of the polygalacturonate chain, the distribution pattern of the esterified carboxyl groups has an essential effect based on calcium binding. Gelation occurs because of the formation of junction zones between the smooth regions of GalA through calcium bridges. The most well-known model for Ca²⁺ LMP gelatin is the “egg-box” model, where these are formed between two neighboring chains and stabilized by van der Waals interactions and hydrogen bonds in addition to electrostatic interactions [44,46].

5. Pectin as a Source for Hydrogel

Pectin is widely used in the food sector as a texture modifier, thickener, coating, and gelling agent due to its gel formation capacity, and many functional properties, including good biodegradability, biocompatibility, and non-toxicity. This makes it a good prospect for applications such as pharmaceutics, nutraceutics, and cosmetics. In addition, crosslinked polymers can form hydrogels that can absorb and retain water many times [48].

As mentioned previously, all hydrogel polymer chains are physically, chemically, or radiation-induced crosslinked, and once the process is induced, the obtained network exhibits viscoelastic and elastic properties (Figure 3) [49]. In physical crosslinking reactions, ionic or neutral monomers are dispersed in a solvent (typically water) together with a crosslinking agent. Polymerization is initiated thermally, by UV irradiation, or by a redox initiator system; afterward, the solvent may be removed, and the gel is washed with distilled water to eliminate impurities. Phase separation then occurs, and a hydrogel is obtained when the water present during polymerization exceeds the equilibrium water content of the hydrogel, corresponding to its maximum swelling state. Some of the most common solvents are water, ethanol, water–ethanol mixtures, and benzyl alcohol. They are used in soft tissue engineering, cartilage repair, cell scaffolds, and other regenerative areas. The chemical crosslinking technique involves the monomer connection of polymers on their backbone, or the addition of a crosslinking agent to join two polymer chains. This can be achieved through the reaction of their functional groups with crosslinkers, such as glutaraldehyde, formaldehyde, and di-aldehydes, which are commonly used in this type of crosslinking. This technique involves the incorporation of molecules between polymer chains to promote crosslinking, thereby enhancing the water absorption capacity of the hydrogel by hydrating its porous structure [50]. Radiation crosslinking proceeds through the generation of free radicals in polymer chains upon exposure to high-energy sources such as electron beams, gamma rays, or X-rays. The extent and efficiency of this process are influenced by factors including polymer concentration and the surrounding environment. Unlike conventional chemical crosslinking, radiation-induced methods avoid the use of additional reagents or initiators, which reduces the risk of cytotoxic residues and can improve the overall biocompatibility of the resulting hydrogel. Furthermore, this approach allows simultaneous sterilization during crosslinking and provides a versatile strategy to adjust the composition and mechanical properties of hydrogels [51]. Various pectin biomaterials with different properties have been reported for several applications, each of which requires specific morphology, density, internal pore surface area, and pore size distribution. Therefore, it is important to understand the morphology of these materials [52].

Figure 3. Hydrogels consist of hydrophilic polymer networks that exhibit strong water affinity and require stabilization against dissolution via physical, chemical, or radiation-induced crosslinking mechanisms. The mechanical and biochemical characteristics of hydrogels are intrinsically linked to their crosslinking methodology, whereby hydrogels composed of identical components can exhibit distinct functional properties depending on their crosslinking architecture [53]. Created in BioRender. Sánchez, A. (2025) https://BioRender.com/ughjtcg.

Figure 3. Hydrogels consist of hydrophilic polymer networks that exhibit strong water affinity and require stabilization against dissolution via physical, chemical, or radiation-induced crosslinking mechanisms. The mechanical and biochemical characteristics of hydrogels are intrinsically linked to their crosslinking methodology, whereby hydrogels composed of identical components can exhibit distinct functional properties depending on their crosslinking architecture [53]. Created in BioRender. Sánchez, A. (2025) https://BioRender.com/ughjtcg.

6. Pectin Hydrogel Applications

Among natural polymers, pectin has attracted attention as an appealing biomaterial with several applications. As previously mentioned, characteristics such as good biocompatibility, biodegradability, water-holding capacity, and resistance make pectin hydrogels a versatile biomaterial. Furthermore, pectin is an attractive material for industrial and biomedical applications owing to its low cost, durability, sensitivity, and low toxicity. Numerous fields have applied pectin hydrogels for different purposes, including tissue engineering, drug delivery, and skin-care product formulation, which will be addressed in this section (Table 2) [54].

Table 2. Applications of pectin-derived hydrogels in different fields.

Field of Application	Type of Hydrogel	Main Outcome	Reference
Agriculture	Sodium alginate/pectin hydrogel	Bacillus subtilis ZF71 was loaded into the synthesized hydrogel for controlling the incidence of Fusarium root rot in cucumber. The developed hydrogel exhibited a 90% coating uniformity among seeds. The developed hydrogel enabled the conservation of B. subtilis ZF71 cells’ viability. Greenhouse assays occurred in 53.26% control efficiency of Fusarium.	[55]
Environment	Pectin hydrogel-metal–organic framework	The experimental variables for evaluating metal removal capacity included contact time, pH, and concentration. The synthesized hydrogel exhibited 95.11% adsorption efficiency of Cu(II), and 97.75 mg/g capacity at pH 5. When evaluated towards Cu(II), the obtained hydrogel displayed 92.62% removal efficiency and 28.189 mg/g capacity at 1 min.	[56]
Biomedicine	Oxidized pectin-containing type I collagen hydrogel	Ozonation (25 mg/h) at a flow rate of 1 L/min) was utilized to increase the hepatogenic performance of pectin-containing type I collagen hydrogel. 40 min of ozonation improved the migration and albumin production in HepG2 cells upon exposure to the synthesized hydrogel. When HepG2 cells were transplanted into mature male Balb/c mice, the developed hydrogel, combined with 40 min of ozonation, decreased fibrotic changes and immunological responses after 14 days.	[57]
Food industry	Pectin and fish bone powder hydrogel	The synthesized hydrogel was utilized as a fat replacer in beef patty samples. The incorporation of the developed hydrogel reduced fat levels while increasing calcium content. The evaluation of 25% of the synthesized hydrogel decreased microbial count when evaluating beef patty samples at 4 °C for 7 days. At 25%, the reported hydrogel also downregulated thiobarbituric acid reactive substances levels.	[58]

Table 2. Applications of pectin-derived hydrogels in different fields.

Field of Application	Type of Hydrogel	Main Outcome	Reference
Agriculture	Sodium alginate/pectin hydrogel	Bacillus subtilis ZF71 was loaded into the synthesized hydrogel for controlling the incidence of Fusarium root rot in cucumber. The developed hydrogel exhibited a 90% coating uniformity among seeds. The developed hydrogel enabled the conservation of B. subtilis ZF71 cells’ viability. Greenhouse assays occurred in 53.26% control efficiency of Fusarium.	[55]
Environment	Pectin hydrogel-metal–organic framework	The experimental variables for evaluating metal removal capacity included contact time, pH, and concentration. The synthesized hydrogel exhibited 95.11% adsorption efficiency of Cu(II), and 97.75 mg/g capacity at pH 5. When evaluated towards Cu(II), the obtained hydrogel displayed 92.62% removal efficiency and 28.189 mg/g capacity at 1 min.	[56]
Biomedicine	Oxidized pectin-containing type I collagen hydrogel	Ozonation (25 mg/h) at a flow rate of 1 L/min) was utilized to increase the hepatogenic performance of pectin-containing type I collagen hydrogel. 40 min of ozonation improved the migration and albumin production in HepG2 cells upon exposure to the synthesized hydrogel. When HepG2 cells were transplanted into mature male Balb/c mice, the developed hydrogel, combined with 40 min of ozonation, decreased fibrotic changes and immunological responses after 14 days.	[57]
Food industry	Pectin and fish bone powder hydrogel	The synthesized hydrogel was utilized as a fat replacer in beef patty samples. The incorporation of the developed hydrogel reduced fat levels while increasing calcium content. The evaluation of 25% of the synthesized hydrogel decreased microbial count when evaluating beef patty samples at 4 °C for 7 days. At 25%, the reported hydrogel also downregulated thiobarbituric acid reactive substances levels.	[58]

6.1. Drug Delivery

Owing to their three-dimensional structure, pectin hydrogels have brought innovation into the pharmacological field, with many drug delivery applications. The mechanism of action can be mainly associated with their capacity to swell and gradually release bioactive compounds in a controlled manner. Their natural pH-sensitivity allows targeted release in acidic environments such as the stomach or in more neutral conditions of the intestine. Moreover, their susceptibility to enzymatic degradation enhances site-specific delivery, while ionotropic crosslinking with calcium ions provides structural stability and fine-tunes the diffusion rate of the encapsulated drugs. Properties such as hydrophilicity, biocompatibility, biodegradability, capacity to maintain tissue humidity, and high water-holding capacity (WHC) make pectin a suitable material for drug delivery purposes. An alternative method for targeted delivery has emerged, which is commonly known as a two-component system consisting of a polymer structure with a high WHC, serving as a vehicle without any unintended chemical modification of the drug. According to recent research, an ideal hydrogel remains chemically and physically stable before targeted delivery and degrades after drug delivery. By using this material, the incurable impacts, such as failure to degrade in the body caused by systems composed of inorganic materials, can be solved and provide specific site delivery and controlled release of therapeutic site [59,60,61]. The biocompatibility of pectin hydrogels permits a flexible design that allows pharmacological functions such as healing. A self-healing hydrogel for drug release and enhanced tumor therapy was designed using pectin-acyl hydrazide and charged with doxorubicin. The results suggest that the microporous structure was ideal for biodegradability and, at the same time, effective on tumor growth inhibition compared to the traditional treatment (doxorubicin injection) and eliminated the side effects [61]. Chang et al. [62] synthesized a self-healing pectin–cellulose hydrogel loaded with limonin and applied it to lung cancer cells. The hydrogels showed good biocompatibility, gelation, and proper sustained limonin release, which significantly inhibited lung adenocarcinoma proliferation, migration, and even promoted apoptosis. Overall, it has great potential as a treatment option for lung cancer. A pectin–cellulose hydrogel demonstrated an efficient encapsulation system for the cytarabine drug (48.5–82.3% loading range) used for an anticancer treatment, which also ensured sustained release in an adequate time lapse, showed no side symptoms, toxicity, irritability, or any organ degeneration [59,60,61]. Because of their pH sensitivity, pectin hydrogels are generally useful in acidic environments. A pectin–gelatin hydrogel showed a high swelling capacity of approximately 90%, high stability, moderate compressive modulus, and oxygen permeability. All these qualities allow the hydrogel to deliver curcumin to infected wounds four times faster than free curcumin [63]. Since stimuli-responsive drug delivery systems seem to be in extreme demand, a polyvinylpyrrolidone and pectin-based hydrogel for controlled delivery was designed. Ceftriaxone sodium was a model drug, which was released at 91.82% efficiency through the hydrogel during a 2 h lapse, with a consistent and controlled flow [64]. As mentioned before, a specific quality that makes hydrogels an excellent drug delivery vehicle is their capacity to respond to stimuli such as pH and REDOX reactions. A REDOX-responsive thiolate pectin-based hydrogel allowed the release of acetaminophen, which is a potential smart material for innovative drug systems [65]. Furthermore, pectin hydrogels have also been used to treat gastrointestinal diseases. Jung et al. [66] encapsulated indomethacin in hydrogels and immersed them in intestinal fluids. The results indicated that charge modification of pectin improves the encapsulation efficiency of colon-targeted drugs through oral administration.

6.2. Tissues Engineering

Recently, tissue engineering has emerged to repair and/or improve the function of damaged tissues, bones, and organs. Hydrogel systems possess specific properties, such as viscoelasticity or oxygen permeability, and they can resemble the extracellular matrix of tissues as well as form scaffolds where cells can self-organize, proliferate, rebuild the target tissue, and promote regeneration as they act by mimicking the extracellular matrix, providing a three-dimensional porous scaffold that supports cell adhesion, proliferation, and differentiation [67,68]. Biocompatibility may be the most important characteristic of pectin hydrogels as a biomaterial for biomedical applications. Because of this quality, different hydrogel compositions, including the addition of complementary substances, are being tested to improve this capacity. The addition of κ-carrageenan improved pectin gel biocompatibility by reducing Tumor Necrosis Factor-alpha, and nuclear factor-kappa B activation compared with the control (pectin only) [69]. An oxidized pectin/N-succinyl chitosan hydrogel containing graphene oxide (OP/NSC/GO) was developed as a tissue engineering tool. In addition to its fast gelation time, the mechanical properties of the hydrogel showed excellent antihemolytic activity. They were then applied to electroactive tissues [70]. Pectin materials have been found to have enormous potential for bone tissue engineering applications because they promote the nucleation of the mineral phase if they are immersed in adequate physiological solutions. This forms biomimetic constructs that better mimic the natural architecture of the bone. Polyvinyl alcohol (PVA)-pectin hydrogels have been shown to induce osteogenic capacity for bone tissue regeneration. The hydrogel accelerated the in vitro bone healing process after femoral defect transplantation. It also enhanced osteoblast proliferation and adhesion. Their ability to be crosslinked with Ca²⁺ not only improves mechanical properties but also participates in cellular signaling pathways such as Ca²⁺/Calmodulin kinase II, and Bone morphogenetic proteins-Mothers against decapentaplegic homolog 1 (an intracellular mediator of BMP signaling), which are essential for bone regeneration and osteogenesis. Bone marrow-derived mesenchymal stem cells were charged on a hydrogel to maximize their osteogenic properties. The results showed that the hydrogel provided a suitable microenvironment for the adhesion, proliferation, and differentiation of cells, and promoted bone regeneration in vivo. This indicated that they may serve as 3D scaffolds for bone healing and regeneration. A pectin PVA/polyethylene glycol (PEG) hydrogel also showed potential as an articular cartilage tissue graft. It even exhibited mechanical behavior as an appropriate cartilage substitute [71].

6.3. Wound Healing

Wound healing consists of four integrated, continuous, and overlapping phases: hemostasis, inflammation, proliferation, and tissue remodeling or resolution. The events of each phase must occur in this specific sequence at a specific time and continue for a specific duration at an optimal intensity. To heal, hemostatic and inflammatory mechanisms must be intact, proliferative cells must then migrate to and proliferate within the wound area, and angiogenesis and epithelization must finally occur, where collagen is synthesized, cross-linked, and aligned properly to provide strength to the remodeled tissue [72,73]. A gelatin hydrogel crosslinked with oxidized pectin exhibited good wound-healing activity. A hemolysis test proved that the hydrogel did not disrupt the membrane of red blood cells and that the rate of hemoglobin release was lower than 5% [64]. An essential requirement for optimal wound healing is a clean and adequate wound environment that is free from infection, necrotic tissue, and foreign materials [72,73,74]. Therefore, the basic function of dressings used in wound care is to provide a protective barrier to prevent bacterial contamination and absorb exudates. The hydrophilic nature of pectin makes it the optimal polymer for wound healing applications because of its ability to react with wound exudates, and it develops a soft gel that is responsible for the control and sometimes elimination of these fluids. Sinha et al. [75] developed a gum ghatti–pectin hydrogel capable of maintaining a moist environment over the wound. Moreover, it prevents the accumulation of exudates in wounds. The PVA–pectin hydrogel demonstrated an antimicrobial effect in vitro and in vivo assays, as well as a scratch recovery-promoting effect, suggesting that it might be suitable for burn treatment [76]. A chitosan–pectin hydrogel loaded with ciprofloxacin was evaluated using wound-healing assays. The natural humid environment promotes wound healing and improves ciprofloxacin retention time and efficacy, showing it to be an appropriate anti-infective excipient [77].

Furthermore, the hydrophilicity of pectin has a strong anti-inflammatory effect. Pectin hydrogel dressings are widely employed due to their favorable properties, including the ability to create a moist wound environment, absorb exudates, enable easy replacement, and provide controlled drug release. In addition, their inherent transparency allows wound monitoring without the need to remove the dressing. These dressings are suitable for wounds with non-to-moderate exudate, ulcers, skin tears, surgical wounds, burns, and radiation oncology and are safe for neonatal skin. In addition, these types of dressings do not need to be changed regularly and therefore do not interfere with the tissue repairing process, as there is no painful detachment of the band aid [72,78,79]. An Arabic gum pectin hydrogel was loaded with naringin (NAR) to demonstrate its wound healing activity. The loaded hydrogel was able to encapsulate NAR and exhibited an excellent encapsulation efficiency of approximately 99.08%. The hydrogel accelerated wound healing in terms of angiogenesis, re-epithelialization, and collagen deposition in an in vivo rat model. Moreover, it decreased the mRNA levels of inflammatory mediators and apoptosis, myeloperoxidase, malondialdehyde and nitrite, suggesting an anti-inflammatory effect [80].

Therefore, the mechanism underlying wound healing relies on the high-water retention and moisture balance offered by pectin hydrogels, which provides an optimal environment for tissue regeneration, due to their hydrophilic network absorbing wound exudates while maintaining a moist surface that promotes faster epithelialization. Additionally, pectin hydrogels can be loaded with antimicrobial or anti-inflammatory agents (Table 3), enabling sustained release directly at the wound site. This dual action can enhance wound closure and reduce infection risks.

Table 3. Antibacterial activity of pectin-based hydrogels.

Material	Features	Main Results	Reference
Carboxyethyl chitosan (CEC)/oxidized pectin (OP)/polyethyleneimine (PEI)	It was characterized by FTIR, H NMR, and SEM.	Swelling ratios exceeded 700% for CEC/OP hydrogels and 1500% for CEC/OP/PEI hydrogels. They degraded at pH 1 and 3 but remained stable at pH 7.4 and 10 after 168 h. Antibacterial efficacy reached 97.3% for CEC/OP and 98.7% for CEC/OP/PEI against S. aureus and E. coli.	[9]
Carboxymethyl chitosan/pectin/polydopamine/rhEGF	It was characterized by FTIR, SEM, and rheological and mechanical properties evaluation. The hydrogel demonstrates a swelling capacity of 133.313 ± 3.45%	Antimicrobial activity reached inhibition rates of 52.2% against E. coli and 75.4% against S. aureus.	[10]
Chitosan, pectin, PVA, and 3-APDEMS	The developed hydrogels were characterized by FTIR and TGA. The change in swelling (max. 1275%) of hydrogels with change in pH of buffer media indicated the pH-dependent response of prepared stimuli responsive hydrogel. It possessed hydrophilicity (72°) and porosity (79%).	Anti-microbial potential of the fabricated hydrogels was analyzed via liquid diffusion method against E. coli Gram-negative bacteria and S. aureus Gram-positive bacteria. The optical density values of prepared hydrogels against S. aureus are slightly higher as compared to values in E. coli.	[61]
Pectin, polyvinylpyrrolidone, 3-APDEMS, and sepiolite clay	It was characterized by FTIR and SEM. The swelling response ranged from 890 to 1233% after 120 min, depending on crosslinker concentration. All hydrogels degraded after 21 days in PBS pH 7.4.	Hydrogels exhibited remarkable antimicrobial activity against E. coli (zones 23 and 18 mm) and B. subtilis (zone 16 mm).	[64]
Pectin–chitosan with ciprofloxacin-loaded dopamine-modified micelles	It was characterized by H NMR spectrometry, FT-IR, XRD, and DSC.	The developed hydrogels had a porosity between 43.1 and 85.4 mg/cm3, a density between 46.5 and 7.2 mg/cm3, and absorbed more than 150 times their own liquid weight. The pectin–chitosan hydrogels loaded with ciprofloxacin demonstrated drug release properties with enhanced antibacterial activity against Staphylococcus aureus after 24 h, were biocompatible in cytotoxicity and hemolysis assays, and in vivo animal studies and histological examinations showed that they were promising for preventing bacterial infections and promoting tissue regeneration.	[77]
Pectin-glutaraldehyde-glycerol	It was characterized by DSC and FTIR. Glutaraldehyde acted as a cross-linker and glycerol as a plasticizer.	The developed hydrogels exhibited antimicrobial activity against S. aureus, with a larger inhibition zone than MEBO (positive control). Their ability to maintain an acidic environment was expected to act as a barrier against microorganisms and reduce microbial activity.	[78]
Low methoxyl pectin, zeolite (Pz), or 2-thiobarbituric acid (PTBA)	It was characterized by SEM and DSC. Rheological properties were measured. SEM showed higher porosity for PTBA compared with Pz.	Hydrogels exhibited inhibitory effects with diameters of 11 mm (pectin), 8 mm (Pz), and 9 mm (PTBA) against E. coli, and 12 mm, 7 mm, and 9 mm against S. aureus.	[81]
Garlic carbon dots, acrylic acid, pectin, and ammonium persulfate	It was characterized by SEM and FTIR. The average pore size of the developed hydrogel was 1.00 µm.	The hydrogel exhibited an equilibrium swelling ratio of 6.21. The bactericidal rate after 24 h of contact against 1 × 106 CFU/mL of methicillin-resistant S. aureus (MRSA) and multidrug-resistant Salmonella Typhimurium (MRST) exceeded 99.99%. The healing rate of MRSA-infected mouse epidermal wounds reached 93.29% after 10 days of treatment. The hydrogel displayed excellent mechanical properties, which enabled better fitting to wound tissue and facilitated the release of garlic carbon dots.	[82]
Pectin–gelatin with pH dependent release of curcumin	It was characterized by FTIR, XRD, EDX, SEM, and BET analysis. The developed films presented a swelling degree in the range of 189–465% and a water retention capacity of 130–390%, depending on ZnO nanoparticle content.	The hydrogels exhibited improved compression strength and controlled degradation compared with controls. They promoted cell proliferation and migration for wound healing and showed antimicrobial activity against E. coli, S. aureus, and A. niger, with inhibition zones of 22, 19, and 17 mm, respectively. The antifungal activity was consistent with streptomycin (10 µg/disk) against A. niger.	[83]
Chitosan/pectin/ZnO nanoparticles	It was characterized by FTIR, XRD, EDX, SEM and BET analysis. The developed films presented the swelling degree and water retention ability in the range of 189–465 and 130–390%, respectively, according to the content of ZnO nanoparticles. Hydrogels showed an improved compression strength and controlled degradation in comparison with control.	Developed hydrogels demonstrated the improved cell proliferation and migration ability for the effective wound healing; and presented antimicrobial activity against 0.1% bacteria (E. coli and S. aureus) and fungi A. niger inoculums, with inhibition zones of 22, 19, and 17 mm, respectively. The antifungal activity of the developed hydrogel was consistent with that of commercial antifungal agent, Streptomycin (10 µg/disk) against A. niger.	[84]
Pectin and conjugated polyphosphate	Mechanical strength and flexibility of the developed hydrogel were investigated through rheology determination, and it was characterized by FTIR and UV-Vis.	The hemostatic hydrogel exhibited a microporous structure and a controlled release profile of vancomycin, which accelerated wound repair by preventing microbial invasion. Although the inhibition zones were smaller than with vancomycin solution, the hydrogel disk showed sufficient antibacterial performance to prevent infections.	[85]
Polysaccharide from Fructus Ligustri Lucidi (FLL-E) Incorporated in PVA/Pectin Hydrogels	It was characterized by SEM, UV-Vis, FTIR, NMR, and XRD.	The hydrogel promoted wound closure by enhancing collagen synthesis, preventing dysfunction in ECM remodeling via TIMP signaling, accelerating re-epithelialization, degrading inflammatory factors, and enhancing cell proliferation. Antimicrobial tests showed that pectin alone had limited activity, PVA none, and PVA-pectin less than pectin. However, FLL-E incorporation provided notable antibacterial activity against S. aureus and E. coli, indicating that activity was related to drug release.	[86]
Quaternized chitosan and pectin hydrogel loaded with propolis	It was characterized by SEM and FTIR. The disintegration of hydrogel films was studied after immersion in PBS, and water swelling showed increasing trends, reaching a plateau after 8 h.	The antibacterial activity of the hydrogel films was evaluated against S. aureus, S. epidermidis, and S. pyogenes. Blending QCS with pectin reduced antibacterial activity due to charge neutralization. However, incorporation of propolis provided antibacterial activity against S. aureus and S. pyogenes, but not against S. epidermidis.	[87]
Hyaluronic acid/Pectin injectable hydrogel	It was characterized by FTIR, SEM, and X-ray spectroscopy. The hydrogels exhibited self-healing due to Fe3+–COO− interactions, and demonstrated injectability and biocompatibility.	Excess Fe3+ levels provided antibacterial activity. The HA/PT hydrogels reduced S. aureus and Pseudomonas aeruginosa viability by ~99.9% after 120 min and achieved complete bacterial death after 360 min.	[88]
Chitosan, Oxidized Pectin, and Tantalum Metal–Organic Framework Hydrogel	It was characterized by SEM, energy-dispersive X-ray spectroscopy, EDAX mapping, XRD, FTIR, and N2 adsorption/desorption isotherm analysis. The developed hydrogel possessed a particle size of 51 nm and a specific surface area of ~26 m2/g.	The hydrogel films were effective against Yersinia ruckeri, Vibrio fluvialis, Edwardsiella tarda, Lactococcus garvieae, and Streptococcus iniae, with greater efficacy against Gram-positive strains.	[89]
Citrus peel pectin/metal composite hydrogel	It was characterized by texture analysis, FTIR, XPS, XRD, SEM, and TGA. The hydrogels had a weight of 412.9–694.78 mg and thickness of 1.23–2.41 mm.	The release of Cu2+ ions varied with pH, being faster at pH 10 and slower at pH 7. CPP–Cu hydrogels exhibited better antibacterial activity against S. aureus than CPP alone.	[90]
Sodium alginate-pectin/TiO2	It was characterized by FTIR, XRD, FE-SEM, EDX, ICP-OES, and UV-Vis. The hydrogel showed a solubility of approximately 10%.	Antimicrobial potential was confirmed by liquid diffusion against E. coli and S. aureus. Inhibition was greater against S. aureus.	[91]
Pectin, polyacrylic acid and gallic acid (PC-PAAc/GA)	It was characterized by FTIR, XRD, TGA, AFM, and FE-SEM. The hydrogels reached swelling equilibrium in 350 min with 1300% swelling.	Hydrogels containing gallic acid exhibited clear inhibition zones against E. coli and S. aureus, whereas controls without gallic acid showed no inhibition.	[92]
Pectin, cellulose, silk fibroin, and Mg(OH)2	It was characterized by EDX, FE-SEM, XRD, and FTIR. The hydrogels had a swelling ratio of 473–567%. Compressive strength, strain, and Young’s modulus were determined under dry and wet conditions.	Biofilm absorbance decreased progressively from polystyrene (0.76) to Pec-Cel (0.47) and Pec-Cel/SF/Mg(OH)2 nanobiocomposite (0.27), indicating higher antibacterial effect.	[93]
Clindamycin-loaded alginate/pectin/hyaluronic acid hydrogel	It was characterized by FE-SEM, film thickness, and pH evaluations. The water vapor transmission rate ranged from 1153 to 151 g/m2/24 h.	The hydrogels containing 300 µg clindamycin/mg reduced MRSA viability by >5 log (~99.999%).	[94]
Pectin-bacterial cellulose/polypyrrole	It was characterized by TA-XT2i, SEM, and FTIR. The optimal formulation contained 30% bacterial cellulose and exhibited enhanced ibuprofen release under electrical potential.	Hydrogels inhibited Streptococcus and Enterobacter. Ibuprofen-loaded hydrogels demonstrated activity against Gram-positive and Gram-negative strains except E. coli.	[95]
Quaternized chitosan and oxidized pectin	It was characterized by H NMR, FTIR, and XPS. The hydrogel showed self-healing within 30 min, rapid gelation (<1 min), a storage modulus of 394 Pa, and hardness of 700 mN.	QCS showed better antibacterial activity than oxidized pectin, while hydrogel samples displayed poor antibacterial performance, requiring > 500 mg/mL for effectiveness compared with standard antibiotics.	[96]
Water hyacinth cellulose (C), alginate (A), and pectin (P)	It was characterized by FTIR and XRD. The hydrogel exhibited a swelling ratio of 173.28% and a water content of 71.93%.	Hydrogels without quercetin showed no antibacterial activity, whereas incorporation of quercetin increased inhibition zones to 16.4 mm against S. aureus and 21.0 mm against P. aeruginosa.	[97]
Chitosan, dialdehyde bacterial cellulose, and pectin	It was characterized by FTIR and TGA. Swelling decreased from 1750 to 1200% with increasing content of chitosan and pectin.	Hydrogels containing chitosan exhibited inhibition zones of 3.3 to 11.9 mm against S. aureus but showed no inhibition against E. coli.	[98]

Table 3. Antibacterial activity of pectin-based hydrogels.

Material	Features	Main Results	Reference
Carboxyethyl chitosan (CEC)/oxidized pectin (OP)/polyethyleneimine (PEI)	It was characterized by FTIR, H NMR, and SEM.	Swelling ratios exceeded 700% for CEC/OP hydrogels and 1500% for CEC/OP/PEI hydrogels. They degraded at pH 1 and 3 but remained stable at pH 7.4 and 10 after 168 h. Antibacterial efficacy reached 97.3% for CEC/OP and 98.7% for CEC/OP/PEI against S. aureus and E. coli.	[9]
Carboxymethyl chitosan/pectin/polydopamine/rhEGF	It was characterized by FTIR, SEM, and rheological and mechanical properties evaluation. The hydrogel demonstrates a swelling capacity of 133.313 ± 3.45%	Antimicrobial activity reached inhibition rates of 52.2% against E. coli and 75.4% against S. aureus.	[10]
Chitosan, pectin, PVA, and 3-APDEMS	The developed hydrogels were characterized by FTIR and TGA. The change in swelling (max. 1275%) of hydrogels with change in pH of buffer media indicated the pH-dependent response of prepared stimuli responsive hydrogel. It possessed hydrophilicity (72°) and porosity (79%).	Anti-microbial potential of the fabricated hydrogels was analyzed via liquid diffusion method against E. coli Gram-negative bacteria and S. aureus Gram-positive bacteria. The optical density values of prepared hydrogels against S. aureus are slightly higher as compared to values in E. coli.	[61]
Pectin, polyvinylpyrrolidone, 3-APDEMS, and sepiolite clay	It was characterized by FTIR and SEM. The swelling response ranged from 890 to 1233% after 120 min, depending on crosslinker concentration. All hydrogels degraded after 21 days in PBS pH 7.4.	Hydrogels exhibited remarkable antimicrobial activity against E. coli (zones 23 and 18 mm) and B. subtilis (zone 16 mm).	[64]
Pectin–chitosan with ciprofloxacin-loaded dopamine-modified micelles	It was characterized by H NMR spectrometry, FT-IR, XRD, and DSC.	The developed hydrogels had a porosity between 43.1 and 85.4 mg/cm3, a density between 46.5 and 7.2 mg/cm3, and absorbed more than 150 times their own liquid weight. The pectin–chitosan hydrogels loaded with ciprofloxacin demonstrated drug release properties with enhanced antibacterial activity against Staphylococcus aureus after 24 h, were biocompatible in cytotoxicity and hemolysis assays, and in vivo animal studies and histological examinations showed that they were promising for preventing bacterial infections and promoting tissue regeneration.	[77]
Pectin-glutaraldehyde-glycerol	It was characterized by DSC and FTIR. Glutaraldehyde acted as a cross-linker and glycerol as a plasticizer.	The developed hydrogels exhibited antimicrobial activity against S. aureus, with a larger inhibition zone than MEBO (positive control). Their ability to maintain an acidic environment was expected to act as a barrier against microorganisms and reduce microbial activity.	[78]
Low methoxyl pectin, zeolite (Pz), or 2-thiobarbituric acid (PTBA)	It was characterized by SEM and DSC. Rheological properties were measured. SEM showed higher porosity for PTBA compared with Pz.	Hydrogels exhibited inhibitory effects with diameters of 11 mm (pectin), 8 mm (Pz), and 9 mm (PTBA) against E. coli, and 12 mm, 7 mm, and 9 mm against S. aureus.	[81]
Garlic carbon dots, acrylic acid, pectin, and ammonium persulfate	It was characterized by SEM and FTIR. The average pore size of the developed hydrogel was 1.00 µm.	The hydrogel exhibited an equilibrium swelling ratio of 6.21. The bactericidal rate after 24 h of contact against 1 × 106 CFU/mL of methicillin-resistant S. aureus (MRSA) and multidrug-resistant Salmonella Typhimurium (MRST) exceeded 99.99%. The healing rate of MRSA-infected mouse epidermal wounds reached 93.29% after 10 days of treatment. The hydrogel displayed excellent mechanical properties, which enabled better fitting to wound tissue and facilitated the release of garlic carbon dots.	[82]
Pectin–gelatin with pH dependent release of curcumin	It was characterized by FTIR, XRD, EDX, SEM, and BET analysis. The developed films presented a swelling degree in the range of 189–465% and a water retention capacity of 130–390%, depending on ZnO nanoparticle content.	The hydrogels exhibited improved compression strength and controlled degradation compared with controls. They promoted cell proliferation and migration for wound healing and showed antimicrobial activity against E. coli, S. aureus, and A. niger, with inhibition zones of 22, 19, and 17 mm, respectively. The antifungal activity was consistent with streptomycin (10 µg/disk) against A. niger.	[83]
Chitosan/pectin/ZnO nanoparticles	It was characterized by FTIR, XRD, EDX, SEM and BET analysis. The developed films presented the swelling degree and water retention ability in the range of 189–465 and 130–390%, respectively, according to the content of ZnO nanoparticles. Hydrogels showed an improved compression strength and controlled degradation in comparison with control.	Developed hydrogels demonstrated the improved cell proliferation and migration ability for the effective wound healing; and presented antimicrobial activity against 0.1% bacteria (E. coli and S. aureus) and fungi A. niger inoculums, with inhibition zones of 22, 19, and 17 mm, respectively. The antifungal activity of the developed hydrogel was consistent with that of commercial antifungal agent, Streptomycin (10 µg/disk) against A. niger.	[84]
Pectin and conjugated polyphosphate	Mechanical strength and flexibility of the developed hydrogel were investigated through rheology determination, and it was characterized by FTIR and UV-Vis.	The hemostatic hydrogel exhibited a microporous structure and a controlled release profile of vancomycin, which accelerated wound repair by preventing microbial invasion. Although the inhibition zones were smaller than with vancomycin solution, the hydrogel disk showed sufficient antibacterial performance to prevent infections.	[85]
Polysaccharide from Fructus Ligustri Lucidi (FLL-E) Incorporated in PVA/Pectin Hydrogels	It was characterized by SEM, UV-Vis, FTIR, NMR, and XRD.	The hydrogel promoted wound closure by enhancing collagen synthesis, preventing dysfunction in ECM remodeling via TIMP signaling, accelerating re-epithelialization, degrading inflammatory factors, and enhancing cell proliferation. Antimicrobial tests showed that pectin alone had limited activity, PVA none, and PVA-pectin less than pectin. However, FLL-E incorporation provided notable antibacterial activity against S. aureus and E. coli, indicating that activity was related to drug release.	[86]
Quaternized chitosan and pectin hydrogel loaded with propolis	It was characterized by SEM and FTIR. The disintegration of hydrogel films was studied after immersion in PBS, and water swelling showed increasing trends, reaching a plateau after 8 h.	The antibacterial activity of the hydrogel films was evaluated against S. aureus, S. epidermidis, and S. pyogenes. Blending QCS with pectin reduced antibacterial activity due to charge neutralization. However, incorporation of propolis provided antibacterial activity against S. aureus and S. pyogenes, but not against S. epidermidis.	[87]
Hyaluronic acid/Pectin injectable hydrogel	It was characterized by FTIR, SEM, and X-ray spectroscopy. The hydrogels exhibited self-healing due to Fe3+–COO− interactions, and demonstrated injectability and biocompatibility.	Excess Fe3+ levels provided antibacterial activity. The HA/PT hydrogels reduced S. aureus and Pseudomonas aeruginosa viability by ~99.9% after 120 min and achieved complete bacterial death after 360 min.	[88]
Chitosan, Oxidized Pectin, and Tantalum Metal–Organic Framework Hydrogel	It was characterized by SEM, energy-dispersive X-ray spectroscopy, EDAX mapping, XRD, FTIR, and N2 adsorption/desorption isotherm analysis. The developed hydrogel possessed a particle size of 51 nm and a specific surface area of ~26 m2/g.	The hydrogel films were effective against Yersinia ruckeri, Vibrio fluvialis, Edwardsiella tarda, Lactococcus garvieae, and Streptococcus iniae, with greater efficacy against Gram-positive strains.	[89]
Citrus peel pectin/metal composite hydrogel	It was characterized by texture analysis, FTIR, XPS, XRD, SEM, and TGA. The hydrogels had a weight of 412.9–694.78 mg and thickness of 1.23–2.41 mm.	The release of Cu2+ ions varied with pH, being faster at pH 10 and slower at pH 7. CPP–Cu hydrogels exhibited better antibacterial activity against S. aureus than CPP alone.	[90]
Sodium alginate-pectin/TiO2	It was characterized by FTIR, XRD, FE-SEM, EDX, ICP-OES, and UV-Vis. The hydrogel showed a solubility of approximately 10%.	Antimicrobial potential was confirmed by liquid diffusion against E. coli and S. aureus. Inhibition was greater against S. aureus.	[91]
Pectin, polyacrylic acid and gallic acid (PC-PAAc/GA)	It was characterized by FTIR, XRD, TGA, AFM, and FE-SEM. The hydrogels reached swelling equilibrium in 350 min with 1300% swelling.	Hydrogels containing gallic acid exhibited clear inhibition zones against E. coli and S. aureus, whereas controls without gallic acid showed no inhibition.	[92]
Pectin, cellulose, silk fibroin, and Mg(OH)2	It was characterized by EDX, FE-SEM, XRD, and FTIR. The hydrogels had a swelling ratio of 473–567%. Compressive strength, strain, and Young’s modulus were determined under dry and wet conditions.	Biofilm absorbance decreased progressively from polystyrene (0.76) to Pec-Cel (0.47) and Pec-Cel/SF/Mg(OH)2 nanobiocomposite (0.27), indicating higher antibacterial effect.	[93]
Clindamycin-loaded alginate/pectin/hyaluronic acid hydrogel	It was characterized by FE-SEM, film thickness, and pH evaluations. The water vapor transmission rate ranged from 1153 to 151 g/m2/24 h.	The hydrogels containing 300 µg clindamycin/mg reduced MRSA viability by >5 log (~99.999%).	[94]
Pectin-bacterial cellulose/polypyrrole	It was characterized by TA-XT2i, SEM, and FTIR. The optimal formulation contained 30% bacterial cellulose and exhibited enhanced ibuprofen release under electrical potential.	Hydrogels inhibited Streptococcus and Enterobacter. Ibuprofen-loaded hydrogels demonstrated activity against Gram-positive and Gram-negative strains except E. coli.	[95]
Quaternized chitosan and oxidized pectin	It was characterized by H NMR, FTIR, and XPS. The hydrogel showed self-healing within 30 min, rapid gelation (<1 min), a storage modulus of 394 Pa, and hardness of 700 mN.	QCS showed better antibacterial activity than oxidized pectin, while hydrogel samples displayed poor antibacterial performance, requiring > 500 mg/mL for effectiveness compared with standard antibiotics.	[96]
Water hyacinth cellulose (C), alginate (A), and pectin (P)	It was characterized by FTIR and XRD. The hydrogel exhibited a swelling ratio of 173.28% and a water content of 71.93%.	Hydrogels without quercetin showed no antibacterial activity, whereas incorporation of quercetin increased inhibition zones to 16.4 mm against S. aureus and 21.0 mm against P. aeruginosa.	[97]
Chitosan, dialdehyde bacterial cellulose, and pectin	It was characterized by FTIR and TGA. Swelling decreased from 1750 to 1200% with increasing content of chitosan and pectin.	Hydrogels containing chitosan exhibited inhibition zones of 3.3 to 11.9 mm against S. aureus but showed no inhibition against E. coli.	[98]

6.4. Food

Pectin, as expected from such versatile biomaterials, has applications beyond healthcare. It proved to be a useful food additive which can improve mechanical properties, is non-toxic, reduces water solubility, is highly available, and possesses antiviral and antimicrobial activities [99]. Moreover, pectin hydrogels with other relevant biological properties have been applied in the development of new food products with specific textures for specific purposes while improving food quality and providing functional advantages to customers. Also, these composites can be employed for bioactive compound encapsulation and their targeted release to specific digestive tract regions [100]. Pectin hydrogels can be added to foods as fat mimetics or fat replacers, texturizers replacing starch, probiotic delivery systems, or micro- and nano-encapsulating agents to protect antioxidant compounds due to their encapsulation capacity that protects bioactive compounds from degradation under gastric conditions, and their gelation properties that provides desirable rheological properties without compromising sensory quality. Furthermore, pectin hydrogels can act as controlled-release carriers for nutrients, ensuring their delivery in specific regions of the digestive tract, which increases bioavailability and functional value of fortified foods [99]. Kopjar et al. [101] prepared hydrogels based on pectin and blackberry juice to additionally fortify them with apple fiber. In addition to evaluating the stability of phenolic compound retention and antioxidant activity, α-glucosidase inhibition for antidiabetic effects was assessed. The authors concluded that hydrogel could be used as an intermediate or ingredient to improve the development of innovative food products by increasing their fiber content and antioxidant potential. By loading a pectin-PEG hydrogel with health-promoting molecules such as vitamin D, Ca²⁺, and Fe²⁺, the obtained matrix could protect charged nutrients from the gastric environment. As a result, a higher co-release of nutrients is achieved at the intestinal site [102]. Mekala et al. [103] synthesized a pectin hydrogel loaded with a vitamin complex (β-carotene, cholecalciferol, α-tocopherol, and ascorbic acid) and evaluated its stability. Vitamin encapsulation on the hydrogel allowed its preservation and improved its strength over the storage time. In contrast, Yan et al. [104], created a soy protein isolate, and pectin hydrogel loaded with probiotic bacteria Lactobacillus paracasei LS14. Under simulated gastrointestinal conditions, the gel was able to inhibit bacterial degradation and reach higher cell viability than the control. Therefore, they concluded that pectin hydrogels have great potential as functional ingredients in probiotic-containing food development.

6.5. Agro-Industrial

Mohnen, D. [25] established that pectin may play a major role in growth, development, morphogenesis, defense, signaling, and several other cellular functions of plants. Therefore, pectin hydrogels have several beneficial effects on plants. Natural polymers are environmentally friendly, particularly in the agro-industrial sector. As a general approach to agro-waste product management, pectin extraction has become an innovative strategy for biomass waste exploitation. Added value has been discovered by extracting pectin from biomass waste [105]. Pectin hydrogels have proven to be efficient vehicles for agriproducts, such as fertilizers and pesticides, and their distribution functions as a controlled-release system through swelling–deswelling cycles which reduces the frequency of applications, minimizes environmental contamination, and enhances the efficiency of agricultural inputs. A pectin hydrogel from depolymerized lignocellulose and cross-linked by CaCl2 was demonstrated to be an effective carrier for compounds and to have a controlled delivery, as well as being an eco-friendly technology for plant growth and increasing crop yield [106]. Furthermore, various natural hydrogels have been used to reduce drought stress in plants because of pectin hydrogels excellent WHC helping soils retain moisture for longer periods [107]. Treatment with pectin and starch proved to maximize this, with an increase of 2.8- to 2.0-fold compared to the control (soil), which resulted in improved yield and quality for tomatoes and other crops.

6.6. Environmental and Bioremediation

Pectin hydrogels have been used to remove toxic heavy metals from aqueous samples for application in water bioremediation as they act primarily via ion-exchange and adsorption processes. The free carboxyl groups on the pectin backbone interact with heavy metals such as Pb²⁺, Cr³⁺, and Cu²⁺, enabling their efficient removal from contaminated water. These hydrogels can also be regenerated through desorption, making them reusable in multiple cycles. Mahmoud et al. [108] synthesized a pectin hydrogel from mandarin peels, crosslinked by CaCl₂. The hydrogel showed significant swelling capacity and stability for absorption, and the removal of Cr (99.73, 99.87, and 99.87%) and Pb (99.02, 98.55, and 98.55%) from tap water, seawater, and industrial wastewater, respectively, was confirmed to be effective. In contrast, Pirsa et al. [109] used gluten/pectin/Fe₃O₄ hydrogel to reduce sediment contamination in a lake. The experiments showed that hydrogel could remove 62% of the total heavy metals and 42% of the organic acids present. The grapefruit-derived pectin hydrogel also demonstrated a significant absorption rate of heavy metals, indicating its potential as a tool for pollutant removal [110]. Overall, pectin shows potential for membranes development for seawater and water remediation along with wastewater treatment, due to their ability to adsorb and desorb metals and other contaminants to be recovered for future uses. Pectin hydrogels can be used for several adsorption–desorption cycles and then be discarded with no environmental impact [111].

6.7. Other Materials

Compared with synthetic hydrogels such as polyacrylamide, polyethylene glycol (PEG), or polyvinyl alcohol (PVA), pectin hydrogels present clear advantages such as biocompatibility, biodegradability, non-toxicity, and cost-effectiveness, making them appropriate in several bio-applications, along with a strengthened sustainability profile due to their renewable origin and their capacity to be extracted from agro-industrial by-products. However, pectin hydrogels often show lower mechanical strength, less control over gelation kinetics, sensitivity to pH and ionic environment, and variability through batches associated with the natural source. Therefore, synthetic hydrogels, in contrast, offer superior mechanical properties, reproducibility, and reliable control of physical-chemical characteristics, but may suffer from poor bioactivity, potential toxicity from residual monomers, or slower biodegradation unless carefully engineered [112]. On the other hand, hybrid hydrogels that combine natural polymers like pectin with synthetic polymers, or incorporate nanomaterials for reinforcement, have shown promise in bridging this gap by achieving improved mechanical strength while preserving biocompatibility [113].

Similar comparisons have emerged in the food sector, where hydrogels for food preservation or smart packaging are evaluated for their swelling, barrier properties, and sensory impact versus synthetic or semi-synthetic analogs where stability, safety, and environmental concerns are key factors [114].

7. Future Prospects

Research on pectin-based hydrogels should address several key challenges to enable their broader application. Also, improving mechanical strength and reproducibility remains essential, since variability in pectin source and extraction protocols often limits consistency and scalability [115]. Standardization and regulatory frameworks will also be critical to support translation into biomedical and food products [116]. At the same time, multifunctional and smart hydrogels responsive to pH, temperature, or external stimuli offer exciting opportunities for advanced drug delivery and wound healing systems [117]. In the food sector, recent studies show the potential of tailoring hydrogel texture and digestion behavior to enhance nutrient release and stability, though more in vivo validation is needed [118]. Overall, future progress will depend on interdisciplinary approaches that combine materials science and biotechnology to achieve sustainable, safe, and commercially viable pectin hydrogels.

8. Conclusions

Pectin is a useful component of cell walls of fruits and vegetables with a multifaceted structure that depends on its origin and extraction method, such as hydrolysis, ultrasound, microwave, or enzymatic extraction. However, the resulting pectin properties must be defined depending on the desired application. One of the most important characteristics of extracted pectins is the DE. Low-methoxyl pectins are obtained through methods that involve extreme conditions; however, extractions using ultrasound, microwave, or subcritical water extraction result in high-methoxylated pectins. DE is an important parameter for the pectin to form gels due to its different mechanisms of linking the neighboring chains of pectin to form a filamentous network with elevated water-holding capacity. Pectin hydrogels have demonstrated great potential and have been widely applied in biomedical and industrial fields due to their low cost, biodegradability, and versatility. They can be processed into films, microparticles, nanoparticles, membranes, beads, pellets, and xerogels, exhibiting enhanced water-holding capacity, permeability, biocompatibility, favorable mechanical performance, and phase flexibility. These attributes offer opportunities to design new formulations and develop innovative materials with enhanced properties for various applications soon. Considering this, it is noteworthy to mention that there are various challenges associated with manufacturing, obtaining, and evaluating pectin hydrogels. For instance, it is important to consider that the composition and properties of pectin can vary significantly depending on the plant source, extraction method, and processing conditions, making it difficult to produce consistent hydrogels or associated nanomaterials. Together with this, achieving precise control over the crosslinking density and distribution is challenging yet critical for tuning hydrogel properties, where factors such as pH, temperature, and ion concentration must be carefully optimized. On the other hand, through this review, it has been noted that pectin hydrogels often have poor mechanical strength compared to synthetic polymers, limiting their use in certain applications. For this, improving the toughness of pectin-based hydrogels while maintaining biocompatibility is an ongoing challenge, as well as their degradation rate, scalable production, controlled release, and standard characterization approaches.