Gelatin alternatives for the food industry: recent developments, challenges and prospects

Dynamic Bonds in Biopolymers: Enhancing Performance and Properties

As the demand for polymer materials increases, conventional petroleum-based synthetic polymers face several significant challenges, including raw material depletion, environmental issues, and the potential for biotoxicity in biological applications. In response, bio-based polymers derived from natural sources, such as cellulose, alginate, chitosan, and gelatin, have garnered attention due to their advantages of biocompatibility and biodegradability. However, these polymers often suffer from poor physical stability due to the high density of hydrogen bonds and the large structure of pyranose rings. This review explores the potential of incorporating dynamic covalent bonds into biopolymers to overcome these limitations. The chemical structures of biopolymers contain numerous functional groups that can serve as anchoring sites for dynamic bonds, thereby enhancing the mechanical properties and overall stability of the polymer network. The review discusses the performance improvements achievable through dynamic covalent bonds and examines the future potential of this technology to enhance the physical properties of biopolymers and expand their applicability in biological fields.

Embedding Bioprinting of Low Viscous, Photopolymerizable Blood-Based Bioinks in a Crystal Self-Healing Transparent Supporting Bath

Protein-based hydrogels have great potential to be used as bioinks for biofabrication-driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed within a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, crystal self-healing embedding bioprinting (CLADDING) is introduced based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins is evaluated (i.e., molecular weight distribution, isoelectric point, and ionic content), as well as the formation of gelatin-gum arabic microparticles as a function of pH, temperature, solvent, and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self-healing properties for interaction with protein-based bioinks. This support bath achieved transparency, which boosted light permeation within the bath. Bioprinted constructs fully composed of platelet lysates encapsulating a co-culture of human mesenchymal stromal cells and endothelial cells are obtained, demonstrating a high-dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells without any additional support.

Exploring Noncentrifugal Sugar as a Partial Replacement for White Sugar in Low Methoxyl Pectin Confectionery Gels: Impacts on Physical and Rheological Properties

Noncentrifugal sugar (NCS) is an unrefined, dark brown sugar containing minerals and plant secondary metabolites, unlike refined white sugar (WS). This study explored using NCS in confectionary jellies as an alternative sugar. We used different concentrations of NCS and WS to prepare low methoxyl pectin (LMP) confectionery gels characterized by their physical and rheological properties along with time-domain nuclear magnetic resonance (TD-NMR) relaxometry. The strongest LMP gel, with a hardness of 0.94 N, was achieved by substituting 25% of WS with NCS at a low CaCl2 concentration (0.075 M). Gels with up to 50% WS replaced by NCS showed comparable hardness to standard LMP gels made solely with WS at a 0.15 M CaCl2 concentration, attributed to NCS's unique constituents. The NCS-WS gel exhibited the shortest T2 values (139.8 ms) and self-diffusion coefficient values (4.99 × 10-10 m2/s), indicating a denser, more cross-linked structure that restricted water mobility. These findings suggest NCS's complex role in affecting LMP gels' chemical and physical properties, highlighting its potential as a partial WS replacement in LMP gelation-based products, with an additional source of minerals and antioxidants.

The Effect of Cellulose Nanocrystals on the Molecular Organization, Thermomechanical, and Shape Memory Properties of Gelatin-Matrix Composite Films

Gelatin is a natural hydrocolloid with excellent film-forming properties, high processability, and tremendous potential in the field of edible coatings and food packaging. However, its reinforcing by materials such as cellulose nanocrystals (CNC) is often necessary to improve its mechanical behavior, including shape memory properties. Since the interaction between these polymers is complex and its mechanism still remains unclear, this work aimed to study the effect of low concentrations of CNC (2, 6, and 10 weight%) on the molecular organization, thermomechanical, and shape memory properties in mammalian gelatin-based composite films at low moisture content (~10 weight% dry base). The results showed that the presence of CNCs (with type I and type II crystals) interfered with the formation of the gelatin triple helix, with a decrease from 21.7% crystallinity to 12% in samples with 10% CNC but increasing the overall crystallinity (from 21.7% to 22.6% in samples with 10% CNC), which produced a decrease in the water monolayer in the composites. These changes in crystallinity also impacted significantly their mechanical properties, with higher E' values (from 1 × 104 to 1.3 × 104 Pa at 20 °C) and improved thermal stability at higher CNC content. Additionally, the evaluation of their shape memory properties indicated that while molecular interactions between the two components occur, CNCs negatively impacted the magnitude and kinetics of the shape recovery of the composites (more particularly at 10 weight% CNC, reducing shape recovery from 90% to 70%) by reducing the netting point associated with the lower crystallinity of the gelatin. We believe that our results contribute in elucidating the interactions of gelatin-CNC composites at various structural levels and highlights that even though CNC acts as a reinforcement material on gelatin matrices, their interaction are complex and do not imply synergism in their properties. Further investigation is, however, needed to understand CNC-gelatin interfacial interactions with the aim of modulating their interactions depending on their desired application.

Extraction and characterization of collagen and gelatin from body wall of sea cucumbers Stichopus horrens and Holothuria arenicola

Background

Marine invertebrates, including sponges, molluscs, jellyfish, mussels, and sea cucumbers, are abundant sources of high-quality collagen and offer advantages such as availability, ease of processing, lower inflammatory response, and good metabolic compatibility. Approximately 70% of the total protein in the body wall of sea cucumbers is collagen. Gelatin is a water-soluble protein produced from heat-denatured collagen and has various industrial applications.

Methods

Pepsin-solubilized collagen was extracted from the body wall of two sea cucumber Stichopus horrens and Holothuria arenicola, species found in the Oman Sea and characterized with SDS-PAGE and amino acid composition. Then gelatin was extracted from pepsin-solubilized collagen of S. horrens and some rheological properties were measured.

Results

Amino acid composition and SDS-PAGE analysis showed that the collagen from both species was type I, with one α1 chain and β chains, with molecular weights of 125 and 250 kDa, respectively. Glycine was the most abundant amino acid in the collagen from both sea cucumber species. The pepsin-soluble collagens from both species had high levels of glycine, proline, alanine, glutamic acid, and hydroxyproline. The gelatin from S. horrens had a melting point of 30 °C and displayed exceptional thermal stability, surpassing that of mammalian gelatin. Its gelling point was 5 °C, like that of cold-water fish gelatin, with a viscosity of 2.065 cp-lower than mammal gelatins. These findings suggested that collagen and gelatin from sea cucumbers could be useful in nutraceutical, pharmaceutical and cosmetic industries.

A Review on Fish Skin-Derived Gelatin: Elucidating the Gelatin Peptides-Preparation, Bioactivity, Mechanistic Insights, and Strategies for Stability Improvement

Fish skin-derived gelatin has garnered significant attention recently due to its abundant availability and promising bioactive properties. This comprehensive review elucidates various intricacies concerning fish skin-derived gelatin peptides, including their preparation techniques, bioactive profiles, underlying mechanisms, and methods for stability enhancement. The review investigates diverse extraction methods and processing approaches for acquiring gelatin peptides from fish skin, emphasizing their impact on the peptide composition and functional characteristics. Furthermore, the review examines the manifold bioactivities demonstrated by fish skin-derived gelatin peptides, encompassing antioxidant, antimicrobial, anti-inflammatory, and anticancer properties, elucidating their potential roles in functional food products, pharmaceuticals, and nutraceuticals. Further, mechanistic insights into the functioning of gelatin peptides are explored, shedding light on their interactions with biological targets and pathways. Additionally, strategies aimed at improving the stability of gelatin peptides, such as encapsulation, modification, and integration into delivery systems, are discussed to extend the shelf life and preserve the bioactivity. Overall, this comprehensive review offers valuable insights into using fish skin-derived gelatin peptides as functional ingredients, providing perspectives for future research endeavors and industrial applications within food science, health, and biotechnology.

Preparation of Multifunctional Hydrogels with In Situ Dual Network Structure and Promotion of Wound Healing

As an emerging biomedical material, wound dressings play an important therapeutic function in the process of wound healing. It can provide an ideal healing environment while protecting the wound from a complex external environment. A hydrogel wound dressing composed of tilapia skin gelatin (Tsg) and fucoidan (Fuc) was designed in this article to enhance the microenvironment of wound treatment and stimulate wound healing. By mixing horseradish peroxidase (HRP), hydrogen peroxide (H2O2), tilapia skin gelatin-tyramine (Tsg-Tyr), and carboxylated fucoidan-tyramine in agarose (Aga), using the catalytic cross-linking of HRP/H2O2 and the sol-gel transformation of Aga, a novel gelatin-fucoidan (TF) double network hydrogel wound dressing was constructed. The TF hydrogels have a fast and adjustable gelation time, and the addition of Aga further enhances the stability of the hydrogels. Moreover, Tsg and Fuc are coordinated with each other in terms of biological efficacy, and the TF hydrogel demonstrated excellent antioxidant properties and biocompatibility in vitro. Also, in vivo wound healing experiments showed that the TF hydrogel could effectively accelerate wound healing, reduce wound microbial colonization, alleviate inflammation, and promote collagen deposition and angiogenesis. In conclusion, TF hydrogel wound dressings have the potential to replace traditional dressings in wound healing.

Effect of low-frequency ultrasound-assisted acid extraction on gel properties and structural characterization of sheep's hoof gelatin

In this study, we investigated the effects of various low-frequency ultrasound-assisted extraction processes, including ultrasound-assisted acid-soaked water bath extraction (UAW), ultrasound-assisted water bath extraction after acid soaking (AUW), acid-soaked water bath extraction followed by ultrasonics (AWU), and acid-soaked water bath extraction without ultrasound (CON), on the structural properties, thermal stability, gel properties, and microstructure of sheep's hoof gelatin. The results revealed that the primary components of sheep's hoof gelatin consisted of α1-chain, α2-chain (100-135 kDa), and β-chain. In addition, it was observed that among the three sonication groups, sheep's hoof gelatin extracted in the AUW group exhibited the highest yield (27.16 ± 0.41 %), the best gel strength (378.55 ± 7.34 g), and higher viscosity at the same shear rate. The gelling temperature (25.38 ± 0.45 °C) and melting temperature (32.28 ± 0.52 °C) of sheep's hoof gelatin in the AUW group were significantly higher than those in the other groups (p > 0.05). Moreover, our experiments revealed that the sequence of low-frequency ultrasonic pretreatment processes was a crucial factor influencing the gel properties and structural characteristics of sheep's hoof gelatin. Specifically, the acid treatment followed by the ultrasound-assisted approach in the AUW group yielded high-quality and high-yield sheep's hoof gelatin.

Multifunctional hydrogel dressing based on fish gelatin/oxidized hyaluronate for promoting diabetic wound healing

Non-healing chronic diabetic wound treatment remains an unsolved healthcare challenge and still threatens patients' lives. Recently, hydrogel dressings based on natural biomaterials have been widely investigated to accelerate the healing of diabetic wounds. In this study, we introduce a bioactive hydrogel based on fish gelatin (FG) as a candidate for diabetic wound treatments, which is a recently emerged substitute for mammalian derived gelatin. The composite hydrogel simply fabricated with FG and oxidized hyaluronate (OHy) through Schiff base reaction could successfully accelerate wound healing due to their adequate mechanical stability and self-healing ability. In vitro studies showed that the fabricated hydrogels exhibited cytocompatibility and could reduce pro-inflammatory cytokine expression such as NO, IL-1β, TNF-α, and PGE2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. In addition, the production of reactive oxygen species (ROS), a key marker of free radicals producing oxidative stress, was also reduced by fabricated hydrogels. Furthermore, in vivo experiments demonstrated that the hydrogel could promote wound closure, re-epithelialization, collagen deposition, and protein expression of CD31, CD206, and Arg1 in diabetic mice models. Our study highlights the advanced potential of FG as a promising alternative material and indicates that FOHI can be successfully used for diabetic wound healing applications.

Can Dawul Kurundu (Neolitsea involucrate) leaf extract be used as a plant-based stabilizer in set yoghurt production?

The incorporation of plant-derived stabilizers in food processing and preservation has gained considerable industrial interest. The leaf extract of Neolitsea involucrate, Dawul Kurundu (DK), has proven to be a potent plant-derived stabilizing agent in the food industry. However, the potential of utilizing DK leaf extract in the dairy industry has not yet been proven. Thus, the feasibility of incorporating DK leaf extract in set yoghurt production by assessing its physicochemical, sensory, proximate composition, minerals (calcium and phosphorous), and microbial (Escherichia coli, yeast, and mold) quality parameters during storage at 4°C up to 21 days was assessed. DK leaf aqueous extracts of 0.4% w/v (T2), 0.6% w/v (T3), and 0.8% w/v (T4) were used for testing with the control sample, 0.6% gelatin (T1). Compared to T1, there were no differences in color, taste, texture, and mouthfeel in all DK leaf extract-incorporated yoghurts, demonstrating the suitability of using DK leaf extract to replace the gelatin. A decreasing pattern of pH value was observed during 21 days of the storage period in all treatments, whereas total titratable acidity increased significantly with time. Furthermore, the lowest syneresis value was obtained by T4, demonstrating ideal stabilizing properties at higher incorporation levels. The proximate, mineral, and microbial compositions of all treatments showed no significant difference compared to the control. Therefore, overall results revealed that the 0.8% w/v level of DK leaf extract incorporation (T4) could be used as a potent stabilizer in set yoghurt production by allowing the possibility of replacing the gelatin without compromising its organoleptic properties. Improved and efficient methods for extracting the DK leaf extracts by focusing on their potential functional and health effects should be further examined.

High stretchable and tough xylan-g-gelatin hydrogel via the synergy of chemical cross-linking and salting out for strain sensors

Stretchable and tough hydrogels have been extensively used in tissue engineering scaffolds and flexible electronics. However, it is still a significant challenge to prepare hydrogels with both tensile strength and toughness by utilizing xylan, which is abundant in nature. Herein, we present a novel hydrogel of carboxymethyl xylan(CMX) graft gelatin (G) and doped with conductive hydroxyl carbon nanotubes (OCNT). CMX and G are combined through amide bonding as well as intermolecular hydrogen bonding to form a semi-interpenetrating hydrogel network. The hydrogel was further subjected to salting-out treatment, which induced the aggregation of the CMX-g-G molecular chain and the formation of chain bundles to toughen the hydrogel, the tensile strain, tensile stress, and toughness of CMX-g-G hydrogels were 1.547 MPa, 324 %, and 2.31 MJ m-3, respectively. In addition, OCNT was used as a conductive filler to impart electrical conductivity and further improve the mechanical properties of CMX-g-G/OCNT hydrogel, and a tensile strength of 1.62 MPa was obtained. Thus, the synthesized CMX-g-G/OCNT hydrogel can be used as a reliable and sensitive strain sensor for monitoring human activity. This study opens up new horizons for the preparation of xylan-based high-performance hydrogels.

Sorption Isotherms and Thermodynamic Characteristics of Gelatin Powder Extracted from Whitefish Skin: Mathematical Modeling Approach

Moisture adsorption and desorption isotherms of gelatin extracted from whitefish skin powder (FSGP) at different temperatures across a wide range of water activity were determined along with their thermodynamic properties. Nine mathematical models were utilized for fitting the experimental data and simulating the adsorption and desorption behavior. The thermodynamic properties were determined and fitted to the experimental data. The results showed that Peleg and GAB models were the best fit for FSGP. The energies involved in the adsorption and desorption process of FSGP indicated a stronger dependence on equilibrium moisture content (Xe). When Xe decreased, there was a consistent trend of increasing thermodynamic properties. Both the moisture adsorption and desorption behaviors of FSGP were, therefore, non-spontaneous processes. Linear correlations between the changes in enthalpy and entropy for adsorption and desorption were observed, indicating the presence of enthalpy-entropy compensation for FSGP. For preserving FSGP quality, it should be stored with Xw ≤ 8 (gw/gdm, d.b.) at temperatures below 53 °C and an RH of 50% to avoid it becoming rubbery. These findings are crucial for providing insight into the optimal drying and storage conditions.

Preparation of high content collagen peptides and study of their biological activities

Collagen peptides play an important role in the increasing use of collagen peptides as dietary supplements in food and beverages and as bioactive ingredients in cosmetics, healthcare, and pharmaceuticals. Collagenase enzymatically cleaves gelatin to produce collagen polypeptides. However, the enzymatic activity of collagenase is very low (25900 U) and does not allow for adequate enzymatic digestion. Therefore, proteases are used to assist in enzymatic digestion. Porcine gelatin, bovine gelatin, and fish protein gum were enzymatically digested, and the content of collagen peptides in the enzymatically digested lyophilized powder was identified by high-performance liquid chromatography and mass spectrometry, and then the content of the desired collagen peptides was increased by isolation and purification, and the result of the determination was that the content of collagen peptides was the highest after enzymatic digestion and isolation and purification with the use of porcine gelatin as the raw material, and the content of the collagen peptides was about 45.47%. β-nicotinamide mononucleotide (NMN) was mixed with the prepared samples to determine its antioxidant properties and ability to promote the growth of human dermal fibroblasts. The results showed that the antioxidant capacity was enhanced with the increase of collagen polypeptide content, and NMN could promote the scavenging of DPPH• and •OH free radicals by collagen polypeptides. The ability to promote the growth of human dermal fibroblasts was enhanced with the increase of collagen polypeptide content. This paper aimed to prepare a high content of collagen polypeptides from three raw materials, porcine gelatin, bovine gelatin, and fish protein gum, and further to determine the biological activities.

Packaging films based on biopolymers from seafood processing wastes: Preparation, properties, and their applications for shelf-life extension of seafoods-A comprehensive review

Biopolymers derived from seafood processing byproducts are used to prepare active and biodegradable films as the packaging of food products. These films possess bioactivities to enhance the shelf life of packed foods by proactively releasing antimicrobial/antioxidative agents into the foods and providing sufficient barrier properties. Seafood processing byproducts are an eminent source of valuable compounds, including biopolymers and bioactive compounds. These biopolymers, including collagen, gelatin, chitosan, and muscle proteins, could be used to prepare robust and sustainable food packaging with some antimicrobial agents or antioxidants, for example, plant extracts rich in polyphenols or essential oils. These active packaging are not only biodegradable but also prevent the deterioration of packed foods caused by spoilage microorganisms as well as chemical deterioration. Seafood discards have a promising benefit for the development of environmentally friendly food packaging systems via the appropriate preparation methods or techniques. Therefore, the green packaging from seafood leftover can be better exploited and replace the synthetic counterpart.

Application of 3D- printed hydrogels in wound healing and regenerative medicine

Hydrogels are three-dimensional polymer networks with hydrophilic properties. The modifiable properties of hydrogels and the structure resembling living tissue allow their versatile application. Therefore, increasing attention is focused on the use of hydrogels as bioinks for three-dimensional (3D) printing in tissue engineering. Bioprinting involves the fabrication of complex structures from several types of materials, cells, and bioactive compounds. Stem cells (SC), such as mesenchymal stromal cells (MSCs) are frequently employed in 3D constructs. SCs have desirable biological properties such as the ability to differentiate into various types of tissue and high proliferative capacity. Encapsulating SCs in 3D hydrogel constructs enhances their reparative abilities and improves the likelihood of reaching target tissues. In addition, created constructs can simulate the tissue environment and mimic biological signals. Importantly, the immunogenicity of scaffolds is minimized through the use of patient-specific cells and the biocompatibility and biodegradability of the employed biopolymers. Regenerative medicine is taking advantage of the aforementioned capabilities in regenerating various tissues- muscle, bones, nerves, heart, skin, and cartilage.

Evaluation of Physicochemical Properties of a Hydrocolloid-Based Functional Food Fortified with Caulerpa lentillifera: A D-Optimal Design Approach

This study introduced a D-optimal design mixture to assess the physicochemical properties of a hydrocolloid-based functional food fortified with C. lentillifera. The combination incorporated vital jelly constituents, including extract (10-15%), sweeteners (20-29%), gelling agents (k-carrageenan and locust bean gum (LBG)), and preservatives (0-0.05%). The dependent variables were pH, Total Soluble Solid (TSS) value, and moisture content (MS). By employing the D-optimal design approach, a quadratic polynomial model was developed, demonstrating strong correlations with the experimental data with coefficient determinations (R²) of 0.9941, 0.9907, and 0.9989 for pH, TSS, and MS, respectively. Based on the D-optimal design, the study identified the optimum combination of significant factors with a desirability of 0.917, comprising 14.35% extract, 23.00% sucrose, 21.70% fructose, 26.00% k-carrageenan, 13.00% LBG, 1.95% CaCl₂, and 0% methylparaben. The percentage of residual standard error (RSE) was less than 5%, indicating the reliability of the developed model. Furthermore, color analysis revealed significant differences among the jellies (p < 0.05). HPLC analysis demonstrated that the total sugar content in the fortified jellies was 28% lower compared to commercial jelly. Meanwhile, the bitterness level according to e-tongue showed a reduction of up to 90.5% when compared to the extract. These findings provide a valuable benchmark for the development of functional food products, ensuring their quality, safety, and extended shelf-life.

Current Trends in Gelatin-Based Drug Delivery Systems

Gelatin is a highly versatile natural polymer, which is widely used in healthcare-related sectors due to its advantageous properties, such as biocompatibility, biodegradability, low-cost, and the availability of exposed chemical groups. In the biomedical field, gelatin is used also as a biomaterial for the development of drug delivery systems (DDSs) due to its applicability to several synthesis techniques. In this review, after a brief overview of its chemical and physical properties, the focus is placed on the commonly used techniques for the development of gelatin-based micro- or nano-sized DDSs. We highlight the potential of gelatin as a carrier of many types of bioactive compounds and its ability to tune and control select drugs' release kinetics. The desolvation, nanoprecipitation, coacervation, emulsion, electrospray, and spray drying techniques are described from a methodological and mechanistic point of view, with a careful analysis of the effects of the main variable parameters on the DDSs' properties. Lastly, the outcomes of preclinical and clinical studies involving gelatin-based DDSs are thoroughly discussed.

Duplex droplet digital PCR (ddPCR) for simultaneous quantification of bovine and porcine gelatin in capsules

Detection of bovine and porcine in gelatin-based products is important as species fraud and product mislabeling may have a detrimental impact on customers who have health, ethical, and religious concerns about animal products. The duplex droplet digital PCR (ddPCR) assay using double-quenched probes has been developed for quantification and detection of porcine and bovine DNA in gelatin capsules. A DNA mixture derived from gelatin was found to have a limit of detection as low as 0.001 ng/µl for porcine samples and 0.01 ng/µl for bovine samples. DNA from 12 other distinct species was tested with the bovine and porcine probes, showing high specificity for this method. The test was validated using fifty-five commercial supplement and pharmaceutical capsules, of which 17 were positive for bovine and/or porcine DNA. This study shows that the duplex ddPCR is reliable for routine analysis in the identification of bovine and porcine origins for gelatin capsules.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01204-x.

Understanding the Molecular Conformation and Viscoelasticity of Low Sol-Gel Transition Temperature Gelatin Methacryloyl Suspensions

For biomedical applications, gelatin is usually modified with methacryloyl groups to obtain gelatin methacryloyl (GelMA), which can be crosslinked by a radical reaction induced by low wavelength light to form mechanically stable hydrogels. The potential of GelMA hydrogels for tissue engineering has been well established, however, one of the main disadvantages of mammalian-origin gelatins is that their sol-gel transitions are close to room temperature, resulting in significant variations in viscosity that can be a problem for biofabrication applications. For these applications, cold-water fish-derived gelatins, such as salmon gelatin, are a good alternative due to their lower viscosity, viscoelastic and mechanical properties, as well as lower sol-gel transition temperatures, when compared with mammalian gelatins. However, information regarding GelMA (with special focus on salmon GelMA as a model for cold-water species) molecular conformation and the effect of pH prior to crosslinking, which is key for fabrication purposes since it will determine final hydrogel's structure, remains scarce. The aim of this work is to characterize salmon gelatin (SGel) and salmon methacryloyl gelatin (SGelMA) molecular configuration at two different acidic pHs (3.6 and 4.8) and to compare them to commercial porcine gelatin (PGel) and methacryloyl porcine gelatin (PGelMA), usually used for biomedical applications. Specifically, we evaluated gelatin and GelMA samples' molecular weight, isoelectric point (IEP), their molecular configuration by circular dichroism (CD), and determined their rheological and thermophysical properties. Results showed that functionalization affected gelatin molecular weight and IEP. Additionally, functionalization and pH affected gelatin molecular structure and rheological and thermal properties. Interestingly, the SGel and SGelMA molecular structure was more sensitive to pH changes, showing differences in gelation temperatures and triple helix formation than PGelMA. This work suggests that SGelMA presents high tunability as a biomaterial for biofabrication, highlighting the importance of a proper GelMA molecular configuration characterization prior to hydrogel fabrication.

3D Printing Technology Based on Versatile Gelatin-Carrageenan Gel System for Drug Formulations

Currently, there is a shortage of pediatric medicines on the market, and 3D printing technology can more flexibly produce personalized medicines to meet individual needs. The study developed a child-friendly composite gel ink (carrageenan-gelatin), created 3D models by computer-aided design technology, then produced personalized medicines using 3D printing to improve the safety and accuracy of medication for pediatric patients. An in-depth understanding of the printability of different formulations was obtained by analyzing the rheological and textural properties of different gel inks and observing the microstructure of different gel inks, which guided the formulation optimization. Through formulation optimization, the printability and thermal stability of gel ink were improved, and F6 formulation (carrageenan: 0.65%; gelatin: 12%) was selected as the 3D printing inks. Additionally, a personalized dose linear model was established with the F6 formulation for the production of 3D printed personalized tablets. Moreover, the dissolution tests showed that the 3D printed tablets were able to dissolve more than 85% within 30 min and had similar dissolution profiles to the commercially available tablets. This study demonstrates that 3D printing is an effective manufacturing technique that allows for flexible, rapid, and automated production of personalized formulations.

Impact of Apricot Pulp Concentration on Cylindrical Gel 3D Printing

The process of 3D food printing is a rapidly growing field that involves the use of specialized 3D printers to produce food items with complex shapes and textures. This technology allows the creation of customized, nutritionally balanced meals on demand. The objective of this study was to evaluate the effect of apricot pulp content on printability. Additionally, the degradation of bioactive compounds of gels before and after printing was evaluated to analyze the effect of the process. For this proposal, physicochemical properties, extrudability, rheology, image analysis, Texture Profile Analysis (TPA), and bioactive compounds content were evaluated. The rheological parameters lead to higher mechanical strength and, thus, a decrease in elastic behavior before and after 3D printing as the pulp content increases. An increase in strength was observed when the pulp content increased; thus, sample gels with 70% apricot pulp were more rigid and presented better buildability (were more stable in their dimensions). On the other hand, a significant (p < 0.05) degradation of total carotenoid content after printing was observed in all samples. From the results obtained, it can be said that the gel with 70% apricot pulp food ink was the best sample in terms of printability and stability.

Oral sensation and gastrointestinal digestive profiles of bigels tuned by the mass ratio of konjac glucomannan to gelatin in the binary hydrogel matrix

Bigels with tunable oral sensation and controlled gastrointestinal digestive profiles are highly demanded in the food industry. A binary hydrogel consisting of different mass ratio of konjac glucomannan to gelatin (φ) was designed to fabricate bigels with stearic acid oleogel. The impacts of φ on the structural, rheological, tribological, flavor release, and delivery properties of bigels were investigated. Structural transition of bigels from hydrogel-in-oleogel to bi-continuous, and then to oleogel-in-hydrogel type, as φ increased from 0.6 to 0.8, and then to 1.0-1.2. Enhanced storage modulus and yield stress were achieved along with the increased φ, while the structure-recovery properties of bigel decreased with increased φ. Under all the tested φ, the viscoelastic modulus and viscosity decreased significantly at oral temperatures but maintained the gel state, and the friction coefficient increased along with the increased φ under high chewing degree. Flexible control over the swelling, the lipid digestion and the release of lipophilic cargos were also observed, with the total release of free fatty acids and quercetin significantly reduced with the increased φ. This study presents a novel manipulation strategy to control oral sensation and gastrointestinal digestive profiles of bigels via tuning the fraction of konjac glucomannan in the binary hydrogel.

A Psychrophilic GelMA: Breaking Technical and Immunological Barriers for Multimaterial High-Resolution 3D Bioprinting

The increasing demand for tissue replacement has encouraged scientists worldwide to focus on developing new biofabrication technologies. Multimaterials/cells printed with stringent resolutions are necessary to address the high complexity of tissues. Advanced inkjet 3D printing can use multimaterials and attain high resolution and complexity of printed structures. However, a decisive yet limiting aspect of translational 3D bioprinting is selecting the befitting material to be used as bioink; there is a complete lack of cytoactive bioinks with adequate rheological, mechanical, and reactive properties. This work strives to achieve the right balance between resolution and cell support through methacrylamide functionalization of a psychrophilic gelatin and new fluorosurfactants used to engineer a photo-cross-linkable and immunoevasive bioink. The syntonized parameters following optimal formulation conditions allow proficient printability in a PolyJet 3D printer comparable in resolution to a commercial synthetic ink (∼150 μm). The bioink formulation achieved the desired viability (∼80%) and proliferation of co-printed cells while demonstrating in vivo immune tolerance of printed structures. The practical usage of existing high-resolution 3D printing systems using a novel bioink is shown here, allowing 3D bioprinted structures with potentially unprecedented complexity.

Characterization of Probiotic Pichia sp. DU2-Derived Exopolysaccharide with Oil-in-Water Emulsifying and Anti-biofilm Activities

Probiotic-derived exopolysaccharides are considered as promising sources of carbohydrate with extensive applications in many industries. In the current study, yeast strains were isolated from chicken ingluvies and gizzard samples. According to molecular identification, EPS-producing yeast (Pichia sp. DU2) showed the most similarity to Pichia cactophila (99.67%). Pichia sp. DU2 showed probiotic properties. EPS of Pichia sp. DU2 showed emulsifying activity. The formed emulsions showed 53% (colza oil) and 100% (p-xylene) stability after 24 h. These emulsions were oil-in-water and have stability in the presence of NaCl, KCl, and also acidic and basic conditions. Also, the EPS showed anti-biofilm (29.7-47.6% and 19.06-55.26% against B. cereus and Y. enterocolitica, respectively) and flocculating activities (31.4%). FT-IR showed the presence of various functional groups in EPS structure. Also, its heteropolysaccharide nature was revealed in ¹H-NMR and HPLC analysis. This emulsifying EPS showed significant thermal stability and negative zeta potential, which make it a promising carbohydrate for various industries. Finally, according to the predicted model, the maximal EPS production was achieved at reaction time 36 h, pH 6, yeast extract concentration 1.0%, and sucrose concentration 5%. Pichia sp. DU2 with probiotic properties and producing EPS with emulsifying, anti-biofilm, and flocculating activities can be considered as promising yeast strain in various industries like food and pharmaceutical industries.

Effect of β-cyclodextrin deodorization on the volatile chemicals and functional properties of three types of gelatins

The exploration of deodorization is important for the application of gelatin in food industry. In this work, the effect of β-cyclodextrin (β-CD) deodorization on the volatile chemicals and functional properties of three types of gelatins (commercial porcine skin gelatin, cold water fish skin gelatin, and Chinese longsnout catfish skin gelatin) were studied. The results suggested the odors of commercial gelatins were significantly less than home-extracted gelatins. The β-CD deodorization efficiency was dependent on both β-CD concentration and volatile chemical. (E)-2-Octenal (C8H14O), 1-octen-3-ol (C8H16O), 2-pentyl-furan (C9H14O), and hentriacontane (C17H36) could be deodorized at low β-CD concentration (even at 2 mg/mL). The best β-CD deodorization concentration for 66.7 mg/mL of Chinese longsnout catfish skin gelatin was 30 mg/mL. β-CD addition could not change the gel forming ability and emulsion activity of gelatins, whereas it had different and concentration-dependent effects on the emulsion stability of gelatins. β-CD addition had no obvious effects on the droplet sizes, droplet coalescence and liquid-gel transition behaviors, but had different effects on the creaming of the emulsions stabilized by three types of gelatins. The encapsulation of β-carotene did not significantly change the droplet trimodal size distribution and liquid-gel transition of fish oil-loaded emulsions. However, β-carotene might delay the droplet coalescence. The creaming stability of β-carotene/fish oil-loaded gelatin/β-CD-stabilized emulsions was dependent on the gelatins, β-CD, and β-carotene. Finally, the β-carotene retention in the emulsions was dependent not on β-CD addition but on the nature of the gelatins. These results provided useful information to understand the molecular deodorization behaviors and explore the deodorization of emulsifiers for food emulsions.

Optimization of Conditions for a Freeze-Dried Restructured Strawberry Block by Adding Guar Gum, Pectin and Gelatin

With its high moisture content and tender texture, fresh strawberry is very susceptible to mechanical damage and microbial infection. Drying is one of the most frequently employed methods to extend its shelf life, and freeze-dried restructured strawberry block (FRSB) is an emerging popular food. Here, in order to enhance the quality of FRSB, edible gums of guar gum, pectin, and gelatin were added and the combination was optimized using response surface methodology (RSM) with chewiness, hardness, and organoleptic evaluations of the dried sample as the response indicators. The results showed that the combination addition of 0.10% guar gum, 0.22% pectin, and 0.30% gelatin contributed to the highest comprehensive quality of the dried sample. Compared with the untreated sample, the optimal combination addition of the three edible gums resulted in a higher moisture content for the dried sample (increased by 0.8%), and increased the chewiness, hardness, and porosity by 82.04%, 27.09%, and 3.01%, respectively, while maintaining more original color and forming a denser porous microstructure. The findings in the current work will be useful for the application of edible gums in freeze-dried restructured fruits and vegetables.

Evaluation and Characterization of Hard-Shell Capsules Formulated by Using Goatskin Gelatin

Gelatin is used as an additive in medicine, food, and cosmetics. Gelatin from goatskin is a new excipient that has not been explored by researchers, including for hard-shell capsules. The aim of this study was to evaluate and characterize the hard-shell capsules produced from goatskin gelatin. The goatskin gelatin was extracted by an acid hydrolysis method, and the functional properties were investigated. Hard-shell capsules were then produced from goatskin gelatin, evaluated, and characterized. The gelatin extracted from goatskin had 56.9% ± 0.95 clarity and a pH of 5.11 ± 0.09, 97.51% ± 1.1 protein content, 9.23% ± 0.08 water content, 0.18% ± 0.07 ash content, 2.08% ± 0.35 fat content, gel strength of 298 ± 2.64 gbloom, and viscosity of 27.33 ± 2.07 mPs. The gelatin has met the requirements to be made into hard-shell capsules. The average weight of the hard-shell capsules produced was 96.9 mg with 8.69 standard deviation. The average size of the body and cap length was 18.84 ± 0.64 mm and 10.98 ± 0.30 mm, respectively. The results of capsule evaluation and characterization were as follows: the pH was 4.82 ± 1,27, water content was 10.03 ± 0.21, disintegration time was 4.02 ± 2.09 min, and there was no microbial growth. Thus, the capsules made have met the requirements and can be produced in a large quantity.

Understanding the effects of ultrasound processng on texture and rheological properties of food

The demand for the production of high quality and safe food products has been ever increasing. Consequently, the industry is looking for novel technologies in food processing operations that are cost-effective, rapid and have a better efficiency over traditional methods. Ultrasound is well-known technology to enhance the rate of heat and mass transfer providing a high end-product quality, at just a fraction of time and energy normally required for conventional methods. The irradiation of foods with ultrasound creates acoustic cavitation that has been used to cause desirable changes in the treated products. The technology is being successfully used in various unit operations such as sterilization, pasteurization, extraction, drying, emulsification, degassing, enhancing oxidation, thawing, freezing and crystallization, brining, pickling, foaming and rehydration, and so forth. However, the high pressure and temperature associated with the cavitation process is expected to induce some changes in the textural and rheological properties of foods which form an important aspect of product quality in terms of consumer acceptability. The present review is aimed to focus on the effects of ultrasound processing on the textural and rheological properties of food products and how these properties are influenced by the process variables.

Effects of Acidulants on the Rheological Properties of Gelatin Extracted from the Skin of Tilapia (Oreochromis mossambicus)

This study aimed to evaluate the effects of lactic acid (LA), citric acid (CA), and malic acid (MA) varying in concentration (0.5−2.0% w/w) on the rheological properties of fish gelatin (1.5−6.67% w/w) obtained from the skin of tilapia (Oreochromis mossambicus). The addition of LA, CA, or MA in gelatin dispersions significantly (p < 0.05) weakened their gel strengths, leading to a 14.3−62.2 reduction in gel strength. The gel strength, elastic (G′), and viscous (G″) moduli, as well as the gelling (TG) and melting (TM) temperatures of gelatin dispersions decreased with an increased level of acid added, implying the weakening effects of these acids on junction zones of the gelatin network in aqueous media. The addition of LA had less effect on these rheological properties of gelatin dispersions as compared to that of MA and CA, which were consistent with their effects on the pH of gelatin dispersions. Moreover, the reductions of TG and TM for gelatin dispersions with a higher gelatin concentration (e.g., 6.67% gelatin with 0.5% LA, TG dropped 0.4 °C) due to the addition of LA, CA, or MA were less pronounced compared to those with a lower gelatin content (e.g., 2% gelatin with 0.5% LA, TG dropped 7.1 °C), likely attributing to the stronger buffering effect of the high gelatin dispersion and less percentage reduction in the junction zones in the dispersion due to the addition of an acid. Incorporation of the effects of acids on the linear relationships (R2 = 0.9959−0.9999) between the square of gelatin concentrations and G′ or G″ could make it possible to develop a model to predict G′, G″, phase transition temperatures of gelatin dispersions containing different amounts of gelatin and acid (within the tested range) in the future.

Adjustable Gel Texture of Recovered Crude Agar Induced by Pressurized Hot Water Treatment of Gelidium sesquipedale Industry Waste Stream: An RSM Analysis

A significant amount of bioactive compound-rich solid waste is released during the industrial phycocolloid-centric extraction of Gelidium sesquipedale. The impact of mild pressurized hot water extraction on repurposing this waste for the recovery of agar with an adjustable gel texture is investigated. A two-factor interaction response surface model assessed the influences of the operating temperatures (80 to 130 °C), times (45 and 150 min), pressures (1 to 70 bar), and algae concentrations (3 to 10% (w:v)). At a temperature of 100 °C, a pressure of 10.13 bar, a recovery time of 45 min, and a 10% algae concentration, the working parameters were considered ideal (w:v). Agar with a hardness of 431.6 g, an adhesiveness of -13.14 g.s-1, a springiness of 0.94, a cohesiveness of 0.63, and a gumminess of 274.46 g was produced under these conditions. A combined desirability of 0.78 was obtained for the exposed technology that retrieved gels with a minimum agar yield of 10% and thermal hysteresis between 39 ± 1 and 52 ± 0.5 °C. The fitted design can provide a high techno-commercial value to the agri-food industrial waste stream.

Complexation of fish skin gelatin with glutentin and its effect on the properties of wheat dough and bread

•

A complex of fishskin gelatin and glutenin was formed in dough.

•

Gelatin enhanced the strength and gas-retention capacity of dough.

•

Gelatin improved the porosity and cell size of crumb and the specific volume of bread.

•

Gelatin retarded the firming rate of crumb and starch retrogradation.

•

Gelatin inhibited water diffusion from marginal crumb to crust.

This study aimed to investigate the effect of fish skin gelatin (Gadus morhua, 0.5%, or 1.0%, flour basis) on the properties of wheat (Triticum aestivum) dough and bread. Compared with the control group, the addition of 1.0% gelatin increased the storage modulus and the maximum resistance of dough, resulting in a longer rupture time and a larger final gas-retention volume of the dough. Bread characteristics showed that the specific loaf volume and crumb cell size both increased. Molecular dynamics simulation indicated that gelatin and glutenin segments formed a complex, where a large amount of hydroxyl groups on the surface retarded water mobility in bread. Gelatin-glutentin complexes with the high water-holding capacity inhibited water diffusion from marginal crumb to crust, and decreased starch retrogradation enthalpy and firming rate of crumb. Thus, fish skin gelatin might be a good improver of wheat dough and bread.

Engineered cell-laden thermosensitive poly(N-isopropylacrylamide)-immobilized gelatin microspheres as 3D cell carriers for regenerative medicine

Several studies have focused on using cell carriers to solve the problem of mesenchymal stem cell expansion on regenerative medicine. However, the disadvantages of using prolonged enzymatic treatment and low cell harvest efficiency still trouble researchers. In this study, PNIPAAm-immobilized gelatin microspheres (abbreviated as GNMS) were synthesized using a simple power-driven flow-focusing microinjection system. The developed thermosensitive GNMS can allow easier harvesting of cells from the microspheres, requiring only 10 ​min of low-temperature treatment and 5 ​min of trypsin treatment. The developed GNMS was characterized by Fourier-transform infrared spectroscopy, optical microscopy, and scanning electron microscopy. Further, live/dead staining, F-actin staining, and PrestoBlue cell viability assays were used to evaluate cytotoxicity, cell morphology, cell proliferation, and harvest efficiency. The gene expression of stem cell markers was determined by real-time quantitative PCR (Q-PCR) analysis to investigate the stemness and phenotypic changes in Wharton's jelly-derived mesenchymal stem cells. The results showed that the engineered cell-laden thermosensitive GNMS could significantly increase the cell harvest rate with over 99% cell survival rate and no change in the cell phenotype. Thus, the described strategy GNMS could be the suitable 3D cell carriers in the therapeutic application and opens new avenues for regenerative medicine.

A Novel Bone Gelatin Prepared by Enzymatic Catalysis with High Crosslinking Activity of MTGase for Gelatinization Properties of Minced Pork

A novel gelatin prepared by enzymatic catalysis (type-E bone gelatin) was developed in our group. In this study, the high crosslinking activity of type-E bone gelatin with microbial transglutaminase (MTGase) was found and further used for the gelatinization properties of minced pork. The results showed that the contents of lysine and glutamine in type-E bone gelatin were higher than that of traditional gelatin prepared by acid (type-A gelatin) and alkali (type-B gelatin) methods, which are as action sites for MTGase. The crosslinking degree (79%) of type-E was approximately 4.9 times that of type-A and 5.6 times that of type-B at 1.44 U/g MTGase. Moreover, the type-E gel showed thermal irreversibility when the MTGase concentration was higher than 0.90 U/g due to high crosslinking activity. For minced pork gel, the water-holding capacity and texture properties of minced pork modified with type-E bone gelatin crosslinked by MTGase were improved and cooking loss was significantly reduced.

Effect of Collagen Types, Bacterial Strains and Storage Duration on the Quality of Probiotic Fermented Sheep’s Milk

Collagen has become popular in dietary supplements, beverages and sports nutrition products. Therefore, the aim of this study was to evaluate the possibility of using various doses of collagen and collagen hydrolysate to produce probiotic sheep’s milk fermented with Lactobacillus acidophilus, Lacticaseibacillus casei, Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus. The effects of storage time, type and dose of collagen, and different probiotic bacteria on the physicochemical, organoleptic and microbiological properties of fermented sheep’s milk at 1 and 21 days of refrigerated storage were investigated. The addition of collagen to sheep’s milk increased the pH value after fermentation and reduced the lactic acid contents of fermented milk compared to control samples. After fermentation, the number of probiotic bacteria cells was higher than 8 log cfu g⁻¹. In sheep’s milk fermented by L. acidophilus and L. casei, good survival of bacteria during storage was observed, and there was no effect of collagen dose on the growth and survival of both strains. The addition of collagen, both in the form of hydrolysate and bovine collagen, resulted in darkening of the color of the milk and increased the sweet taste intensity of the fermented sheep’s milk. However, the addition of hydrolysate was effective in reducing syneresis in each milk sample compared to its control counterpart.

Effect of carbon numbers and structures of monosaccharides on the glycosylation and emulsion stabilization ability of gelatin

Herein, the effect of saccharide glycosylation by nine monosaccharides on bovine bone gelatin for the stabilization of fish oil-loaded emulsions was explored. The gelatin modification was analyzed and then the emulsifying properties of monosaccharide-modified gelatins were analyzed at pH 9.0 and 3.0. The results demonstrated that glycosylated gelatin structure, droplet stability, creaming stability, and liquid-gel transition time were dependent on monosaccharide carbon numbers, monosaccharide structures, and solution pH. Glycosylation modification of gelatins did not obviously change the emulsion droplet stability at pH 9.0, whereas it increased the emulsion droplet stability at pH 3.0. Glycosylation modification of gelatins did not obviously change the emulsion creaming index values (5.1%-8.4% at pH 9.0 and 25.8%-33.1% at pH 3.0). Three-carbon and four-carbon monosaccharides glycosylation significantly increased emulsion liquid-gel transition times. This work provided useful information to understand the effects of carbon numbers and structures of monosaccharides on the protein modification.

Production and characterization of gelatin from rabbit bone as bioplastics material by acid pre-treatment

This study aims to find out the effect of hydrochloric acid curing concentration on the characteristics of rabbit bone gelatin and determine the level of hydrochloric acid concentration for the soaking process to produce the best characteristics of rabbit bone gelatin. The material used was 50 kg of Rex rabbit bones obtained from rabbit farms, HCl 4, 5 and 6% and distilled water. The rabbit skin was soaked in hydrochloricacid (4, 5 and 6%) for 4 d as treatment and replicated three times. Gelatin extraction was performed three times at temperatures of 65, 75 and 85°C for 4 h each time and the results obtained were filtered through filter paper. The filtrate was concentrated at 50°C for 5 h. The concentrated filtrate was then poured into a tray before drying in an oven at 50°C until dry. Milling was carried out until it became gelatin powder. This study used a completely randomised design with a unidirectional pattern, and if there was a significant difference, continued with Duncan’s multiple range test. The results showed that the rabbit bone gelatin yield was between 6.18-8.52%, moisture 8.08-8.45%, ash content 8.15-10.93%, pH 3.85-4, protein content 57.09-62.84%, fat content 0.04-0.27%, gel strength 74.47-129.09 bloom, viscosity 3.06-4.26 cP, thick point 10-12°C, melting point 33-35°C and the molecular weights were 85, 120, and 212.5 kDa. The characteristics of rabbit bone gelatin still meet the Standar Nasional Indonesia gelatin range. Curing treatment with 6% HCl gave the best gelatin characteristics.

Marine Polysaccharides in Tailor- Made Drug Delivery

Abstract:

Marine sources have attracted much interest as an emerging source of biomaterials in drug delivery applications. Amongst all other marine biopolymers, polysaccharides have been the mostly investigated class of biomaterials. The low cytotoxic behavior, in combination with the newly explored health benefits of marine polysaccharides has made it one of the prime research areas in the pharmaceutical and biomedical fields. In this review, we focused on all available marine polysaccharides, including their classification based on biological sources. The applications of several marine polysaccharides in recent years for tissue-specific novel drug delivery including gastrointestinal, brain tissue, transdermal, ocular, liver, and lung have also been discussed here. The abundant availability in nature, cost-effective extraction, and purification process along with a favorable biodegradable profile will encourage researchers to continue investigating marine polysaccharides for exploring newer applications in targeting specific delivery of therapeutics.

Cyprinus carpio Skeleton Byproduct as a Source of Collagen for Gelatin Preparation

Byproducts obtained from fish processing account for up to 70% of their live weight and represent a large amount of unused raw materials rich in proteins, fats, minerals, and vitamins. Recently, the management of the use of predominantly cold-water fish byproducts has become a priority for many processing companies. This paper describes the biotechnological processing of byproducts of warm-water Cyprinus carpio skeletons into gelatins. A Taguchi experimental design with two process factors (HCl concentration during demineralization of the starting material and the amount of enzyme during enzyme conditioning of the collagen) examined at three levels (0.5, 1.0 and 2.0 wt%; 0.0, 0.1 and 0.2 wt% respectively) was used to optimize the processing of fish tissue into gelatin. Depending on the preparation conditions, four gelatin fractions were prepared by multi-stage extraction from the starting material with a total yield of 18.7-55.7%. Extensive characterization of the gel-forming and surface properties of the prepared gelatins was performed. Gelatins belong to the group of zero-low-medium Bloom value (0-170 Bloom) and low-medium viscosity (1.1-4.9 mPa·s) gelatins and are suitable for some food, pharmaceutical, and cosmetic applications. During processing, the pigment can be isolated; the remaining solid product can then be used in agriculture, and H₃PO₄Ca can be precipitated from the liquid byproduct after demineralization. The carp byproduct processing technology is environmentally friendly and meets the requirements of zero-waste technology.

Synthesis and fabrication of gelatin-based elastomeric hydrogels through cosolvent-induced polymer restructuring

Hydrogels have a wide range of applications in tissue engineering, drug delivery, device fabrication for biological studies and stretchable electronics. For biomedical applications, natural polymeric hydrogels have general advantages such as biodegradability and non-toxic by products as well as biocompatibility. However, applications of nature derived hydrogels have been severely limited by their poor mechanical properties. For example, most of the protein derived hydrogels do not exhibit high stretchability like methacrylated gelatin hydrogel has ∼11% failure strain when stretched. Moreover, protein derived elastomeric hydrogels that are fabricated from low molecular weight synthetic peptides require a laborious process of synthesis and purification. Biopolymers like gelatin, produced in bulk for pharma and the food industry can provide an alternative for the development of elastomeric hydrogels. Here, we report the synthesis of ureidopyrimidinone (Upy) functionalized gelatin and its fabrication into soft elastomeric hydrogels through supramolecular interactions that could exhibit high failure strain (318.73 ± 44.35%). The hydrogels were fabricated through a novel method involving co-solvent optimization and structural transformation with 70% water content. It is anticipated that the hydrogel fabrication method involves the formation of hydrophobic cores of ureidopyrimidinone groups inside the hydrogel which introduced elastomeric properties to the resulting hydrogel.

Characterization of Fish Gelatin Obtained from Atlantic Cod Skin Using Enzymatic Treatment

In recent years, there has been increased interest in the production of gelatin from alternative sources, such as raw fish materials. Traditionally, gelatin is obtained using an acidic or alkaline treatment. However, these methods have some disadvantages, such as the long times for processing raw materials and the use of large amounts of water and chemicals. Furthermore, milder processing regimes are required for producing fish gelatin. Enzymes could be the solution for improving the technology of fish gelatin production, due to their specificity and ability to increase the rate of collagen digestion. In this work, samples of gelatin from cod skin were obtained using enzymes of bacterial (protosubtilin) and animal (pancreatin) origins. The use of enzymes reduced the duration of extraction by 40%, and the yield of the final product was increased from 51% to 58–60%. The dependence of the contents of the main components of the secondary structure of gelatin and its rheological and thermal properties on molecular weight was also established. In this study, the gelatins obtained without enzymes and with protosubtilin were shown to have the most desirable characteristics, namely of the highest molecular weights and the highest proportion of ordered structures.

Marine Collagen: A Promising Biomaterial for Wound Healing, Skin Anti-Aging, and Bone Regeneration

Marine organisms harbor numerous bioactive substances that can be utilized in the pharmaceutical and cosmetic industries. Scientific research on various applications of collagen extracted from these organisms has become increasingly prevalent. Marine collagen can be used as a biomaterial because it is water soluble, metabolically compatible, and highly accessible. Upon review of the literature, it is evident that marine collagen is a versatile compound capable of healing skin injuries of varying severity, as well as delaying the natural human aging process. From in vitro to in vivo experiments, collagen has demonstrated its ability to invoke keratinocyte and fibroblast migration as well as vascularization of the skin. Additionally, marine collagen and derivatives have proven beneficial and useful for both osteoporosis and osteoarthritis prevention and treatment. Other bone-related diseases may also be targeted by collagen, as it is capable of increasing bone mineral density, mineral deposition, and importantly, osteoblast maturation and proliferation. In this review, we demonstrate the advantages of marine collagen over land animal sources and the biomedical applications of marine collagen related to bone and skin damage. Finally, some limitations of marine collagen are briefly discussed.

Effects of guar gum supplementation on the lipid profile: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Guar gum can be used as an adjuvant in the treatment of dyslipidemia. However, based on data from different studies, the effectiveness of this product is not uniform. Therefore, we conducted a dose-response meta-analysis between guar gum supplementation and lipid profile.

METHODS AND RESULTS

Five databases (Scopus, Web of Science, PubMed/Medline, Embase, and Google Scholar) were searched to identify relevant articles published up to July 2020. The weighted mean difference (WMD) was derived based on the random-effects model. Overall findings were generated from 25 eligible trials. Patients' conditions included hyperlipidemia, diabetes, metabolic syndrome, hypertension, overweight, carotid endarterectomy, and menopausal women. Prescribed gum dose varied between 100 mg/d and 30 g/d for 1-24 months. Compared with control groups, guar gum supplementation decreased total cholesterol (TC) by -20.41 mg/dL (95% CI: -26.76 to -14.07; P < 0.001) and low-density lipoprotein-cholesterol (LDL-C) by -17.37 mg/dL (95% CI: -23.60 to -11.13; P < 0.001), but did not change triglycerides (TG) (WMD: -6.53 mg/dL, 95% CI: -16.03 to 2.97; P = 0.178) and high-density lipoprotein-cholesterol (HDL-C) (WMD: -0.62 mg/dL, 95% CI: -1.68 to 0.44, P = 0.252).

CONCLUSIONS

Guar gum supplementation significantly reduced serum LDL-C and TC levels in patients with cardiometabolic problems, but had neutral effects on TG and HDL-C levels.