Mammalian Gelatin Research Articles

Cold-adaptation of a methacrylamide gelatin towards the expansion of the biomaterial toolbox for specialized functionalities in tissue engineering

Tissue regeneration is witnessing a significant surge in advanced medicine. It requires the interaction of scaffolds with different cell types for efficient tissue formation post-implantation. The presence of tissue subtypes in more complex organs demands the co-existence of different biomaterials showing different hydrolysis rate for specialized cell-dependent remodeling. To expand the available toolbox of biomaterials with sufficient mechanical strength and variable rate of enzymatic degradation, a cold-adapted methacrylamide gelatin was developed from salmon skin. Compared with mammalian methacrylamide gelatin (GelMA), hydrogels derived from salmon GelMA displayed similar mechanical properties than the former. Nevertheless, salmon gelatin and salmon GelMA-derived hydrogels presented characteristics common of cold-adaptation, such as reduced activation energy for collagenase, increased enzymatic hydrolysis turnover of hydrogels, increased interconnected polypeptides molecular mobility and lower physical gelation capability. These properties resulted in increased cell-remodeling rate in vitro and in vivo, proving the potential and biological tolerance of this mechanically adequate cold-adapted biomaterial as alternative scaffold subtypes with improved cell invasion and tissue fusion capacity.

Combination of sodium alginate with tilapia fish gelatin for improved texture properties and nanostructure modification

Fish gelatin (FG) has been studied intensively as a potential replacement for mammalian gelatin; however, modification of the physicochemical properties of FG is often required to make them similar to those of mammalian gelatin. In the present study, sodium alginate (SA) was combined with tilapia FG to modify its properties to resemble those of mammalian gelatin. When the concentration of SA was increased from 0.05 to 0.4% (w/v) in a 6% (w/v) FG gel, the gel strength and hardness increased. However, at 0.60% (w/v) SA, the gel strength and hardness decreased. From 0.2 to greater than 0.4% SA, the gel changed from opaque to translucent. According to the zeta potential results, SA and FG associated via electrostatic interactions. The FG-SA complex coacervates, the SA fibrous network, and the FG-SA complex network were observed using atomic force microscopy. Based on the results, a schematic model was proposed, wherein at low SA concentrations (≤0.2%), FG associates with SA, resulting in large, complex coacervates with a diameter up to 1064 nm. With increasing SA concentrations, formation of complex coacervates was promoted because of the excess of negatively charged SA, which led to complex networks. The complex network structure was coarser than that observed for SA or FG alone. Moreover, the schematic model was further validated at the microstructure level using confocal scanning laser microscopy and Fourier transform infrared spectroscopy. The nanostructure mismatch between FG-SA and pork gelatin resulted in a texture mismatch.

Preparation and Characterization of Gelatin and Antioxidant Peptides from Gelatin Hydrolysate of Skipjack Tuna (Katsuwonus pelamis) Bone Stimulated by in vitro Gastrointestinal Digestion.

In China, a large amount of fish bones are produced during the processing of tuna cans production. For full use of those by-products, gelatin (STB-G) with a yield of 6.37 ± 0.64% was extracted from skipjack tuna (Katsuwonus pelamis) bone using water at 60 °C for 8 h. Amino acid analysis showed that STB-G contained Gly (340.3 residues/1000 residues) as the major amino acid and its imino acid content was 177.3 residues/1000 residues. Amino acid composition, SDS-PAGE, and Fourier transform infrared (FTIR) spectrum investigations confirmed that the physicochemical properties of STB-G were similar to those of type I collagen from skipjack tuna bone (STB-C), but partial high molecular weight components of STB-G were degraded during the extraction process, which induced that the gelatin was easier to be hydrolyzed by protease than mammalian gelatins and was suitable for preparation of hydrolysate. Therefore, STB-G was hydrolyzed under in vitro gastrointestinal digestion (pepsin-trypsin system) and five antioxidant peptides were purified from the resulted hydrolysate (STB-GH) and identified as GPDGR, GADIVA, GAPGPQMV, AGPK, and GAEGFIF, respectively. Among the gelatin hydrolysate, fractions, and isolated peptides, GADIVA and GAEGFIF exhibited the strongest scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (EC50 0.57 and 0.30 mg/mL), hydroxyl radical (EC50 0.25 and 0.32 mg/mL), superoxide anion radical (EC50 0.52 and 0.48 mg/mL), and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical (EC50 0.41 and 0.21 mg/mL). Moreover, GADIVA and GAEGFIF showed a high inhibiting ability on lipid peroxidation in a linoleic acid model system. The strong activities of five isolated peptides profited by their small molecular sizes and the antioxidant amino acid residues in their sequences. These results suggested that five isolated peptides (STP1–STP5), especially GADIVA and GAEGFIF, might serve as potential antioxidants applied in health food industries.

Synthesis of fish gelatin nanoparticles and their application for the drug delivery based on response surface methodology

Fish gelatin nanoparticle is produced using Tilapia fish skin for the first time by the two-step desolvation method. Fish gelatin is chosen for producing gelatin nanoparticles because no experiment have been done in using fish gelatin and to counter the problem associated with the use of mammalian gelatin, such as bovine spongiform encephalopathy disease. The effects of several factors on the particle size such as pH, acetone concentration, glutaraldehyde volume, stirring speed and stirring time are evaluated. Optimum conditions for the formation of gelatin nanoparticles are obtained using response surface method. Fish gelatin nanoparticles with optimum size of can be produced using pH of 2.45, acetone percentage of 16% (vol%), glutaraldehyde , stirring speed of 600 rpm, and stirring time for 6 h. The thermogram and molecular interaction of fish gelatin and fish gelatin nanoparticles are characterized using DSC and FTIR. In vitro drug release kinetic is examined using 5-fluorouracil as the model drug. The entrapment efficiency of 5-fluouracil as model drug is determined to be 40%. Fish gelatin could be used as a good alternative drug carrier for mammalian gelatin.

Lithospermi radix extract-containing bilayer nanofiber scaffold for promoting wound healing in a rat model

This study examined the in vitro characteristics and in vivo wound healing effect of novel Lithospermi radix (LR) extract-containing bilayer scaffolds in a rat model. LR extract, which has been used as a traditional herbal medicine for treating skin wounds, was added to a biocompatible gelatin solution. After glutaraldehyde vapor was used to modify the surface of chitosan scaffolds, various ratios of mammalian gelatin and fish collagen (GF100, GF91 and GF82) were electrospun onto the chitosan scaffolds to manufacture bilayer scaffolds. The porous chitosan scaffolds with a high swelling ratio showed efficient exudate absorption ability. GF91 gelatin nanofibers electrospun at a constant flow rate at 0.1 mL/h and a voltage of 20 kV displayed the optimal characteristics required for cell attachment and skin tissue regeneration. Moreover, the LR extract was successfully released slowly from the GF91 nanofibers. The investigation of the wound-healing activity of the chitosan/gelatin (CGF) bilayer scaffolds revealed that CGF91L provided the highest wound recovery rate in vivo in Sprague-Dawley (SD) rats. Based on its wound-healing effect and beneficial characteristics, the novel LR extract-containing CGF91 bilayer scaffold demonstrates potential as a material for treating skin wounds.

Effect of confectionery solutes on the rheological properties of fish (Oncorhynchus mykiss) gelatin

In this study, gelatin was extracted from the skin of rainbow trout (Oncorhynchus mykiss) and gelation performance was studied with confectionery solutes at different concentrations (0, 10, 20, 40, 60 g/100 mL) as an alternative to mammalian gelatin. Rheological measurements were used to characterise the gelling and melting temperature and the gel modulus. Sorbitol and sucrose addition positively affected the gelation, texture, thermal and rheological properties due to changes of structural properties of the gelatin investigated by FTIR analysis. Addition of sugar or polyol enhanced the formation of triple helix structure and more junction zones were formed between proteins. Notably, gel strength increased from 828 Pa to 2317 Pa and 1996 Pa with the addition of 10 g/100 mL sorbitol and sucrose, respectively. Sorbitol had more significant effects than sucrose, probably due to its higher conformational degrees of freedom. Melting temperature increased from 17.5 °C to 22 °C and 22.1 °C by sorbitol and sucrose addition, respectively. These data suggested that the addition of sorbitol and sucrose triggered the formation of more junction zones which caused to increase in hardness and chewiness values. The enhanced properties of fish gel solutions with confectionery solutes showed the potential for use of this fish gelatin in gummy like candies.

Characterization on the mechanical and physical properties of chicken skin gelatin films in comparison to mammalian gelatin films

The purpose of this study was to investigate the mechanical and physical properties of chicken skin gelatin film as compared to mammalian gelatin films in terms of tensile strength (TS), elongation at break (EAB), puncture force, water vapour permeability (WVP), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), light barrier, thermal properties and microstructure. Three film formulations using 4g gelatin of three different types (chicken skin, bovine, and porcine gelatin) and 1.5g glycerol were prepared under mechanical stirring at a temperature of 45°C. The use of different types of gelatin resulted in different mechanical and physical properties. Results revealed that chicken skin gelatin film was optimal due to its high tensile strength (5.57 MPa) and low WVP (1.29 x 10−9 kPa) rate as compared to bovine and porcine gelatin films. The carboxyl group was revealed to be stronger in FTIR assay for chicken skin gelatin film, while XRD revealed amorphous characteristics at a peak 2Ɵ = 20°. These results contributed to its superior physical characteristics. These desirable characteristics mean that chicken skin gelatin film has remarkable potential as a biodegradable film material as compared to commercial gelatin. It may become a key preferred alternative for producing gelatin films for edible film purposes.

Influence of dynamic high pressure microfluidization on functional properties and structure of gelatin from bighead carp (Hypophthalmichthys nobilis ) scale

Dynamic high pressure microfluidization (DHPM) was applied to treat fish gelatin from bighead carp (Hypophthalmichthys nobilis) scale. The effects of various pressures from 40 to 160 MPa on the functional properties and structural characteristics of fish gelatin were evaluated. The results showed that DHPM significantly improved the emulsifying and foaming properties, as well as the in vitro pepsin digestibility. Surface hydrophobicity of treated fish gelatin was considered to be highly correlated to emulsifying activity with R2 of .99933. DHPM could not change gel strength and molecular weight distribution of fish gelatin, but decreased its melting temperature with the increased pressures. Micro-structural analysis showed that DHPM endowed fish gelatin with polyporous, rough but uncracked microstructure. Practical applications In spite of possessing relatively low melting temperature, fish gelatin is a suitable replacement for mammalian gelatin in low-temperature stored foods including milk and yogurt. At this time, surface-active properties including foaming and emulsifying properties are generally the most important factor for ensuring food quality. However, fish gelatin shows relatively weaker surface-active properties, especially emulsifying/stabilizing function. Our results show DHPM is a physical technology to enhance the surface-active properties of fish gelatin. DHPM will be promising to promote fish gelatin for its applications in the food industry.

НАУЧНОЕ ОБОСНОВАНИЕ ФИЗИЧЕСКИХ СВОЙСТВ РЫБНОГО ЖЕЛАТИНА

The article presents the advantages of fish gelatin available for nutritional purposes in comparison with gelatin of mammals. Factors forming the basic physical properties of gelatin as a structure-forming agent have been identified. The analysis of melting temperature of jelly and the dynamic viscosity of fish gelatin solutions has been carried out. The melting temperature of jelly prepared from fish gelatin is 4°C lower than the minimum normalized value for mammalian gelatin, which is stipulated by the specific features of their amino acid composition. There has been found an increased value of the parameter “dynamic viscosity” (on average 30 mPa·s) in comparison with the standard value of gelatin of animal origin (on average 23 mPa·s). The molecular weight composition of fish gelatin has been determined. Gelatin has been stated not an individual substance, but a multiphase system consisting of a mixture of linear polypeptides and their aggregates. In the molecular weight distribution of fish gelatin 81.7% falls to a high molecular weight fraction with a mass higher than 100 kDa. Compared with gelatin obtained from the skins of cattle fish gelatin has higher content (by 34.7%) of molecular weight fractions (β- and γ-chains) and lower content (by 36.2%) of α-chains. The predominance of high molecular weight fractions in the composition of fish gelatin causes high rates of dynamic viscosity of its solutions. It was established that the interval of temperature transition ‘fibril-globule’ in fish gelatin is 20-25°C, and in animal gelatin - 28-30°C. It has been inferred that the thermal dependences of the rheological properties of fish and animal gelatin are different. It has been substantiated that collagens of different origin give gelatin with different properties. Physical properties of fish gelatin depend on the amino acid composition of a gelatin molecule, which is determined by the nature of collagen, and on the molecular weight distribution of α-, β-, γ-fractions of gelatin, which is determined by technological factors of gelatin production.

Optimization of Gelatin Extraction and Physico-chemical Properties of Fish Skin and Bone Gelatin: Its Application to Panna Cotta Formulas

The utilization of fish processing waste for value-added by-products has attracted considerable attention. The present study aims to evaluate the gelatin extracted from fish skin and bone for application to Panna cotta products. The optimum conditions of gelatin extraction from Sea Bass, Nile tilapia and Red tilapia skin and bone were at 80 and 90 °C for 2.5 h, respectively. Nile tilapia skin and bone gelatins represent the most hydroxyproline content of 45.38 ±1.32 and 23.28±1.12 g, respectively (p0.05). Nile tilapia skin gelatin has the strength gel of 860.50 g which higher than Nile tilapia bone. The foaming ability normally increases at pH 3 to 6 and has emulsifier ability. Sodium chloride (NaCl) and activated carbon have effecting to remove the color and odor of extracted gelatin. Nile tilapia bone gelatin is the most suitable as an ingredient for Panna Cotta recipe. Panna Cotta milk mix berries has the maximum satisfaction levels in the female and male group of 4 to 5 (like very much to like extremely) for their flavor and texture by surveying satisfaction of customer in 5 points hedonic scale (30 persons). The average costs of production are between 0.56-0.71 US$/cup (200 g). Therefore, it can be concluded that fish gelatin can apply the ingredient in Panna Cotta Recipe or cook with another kind of foods. The extracted fish gelatin has desirable chemical and physical properties. It is suitable as a food ingredient which aspects as an alternative source of mammalian gelatin.

Characteristics and Physicochemical Properties of Gelatin Extracted from Scales of Seabass (Lates calcarifer) and Grey Mullet (Mugil cephalus) in Vietnam

ABSTRACTIn this study, gelatin was obtained from the scales of seabass (Lates calcarifer) and grey mullet (Mugil cephalus) collected in Vietnam by using Alcalase® 2.4 L FG for pretreatment and electrochemically activated water with pH 2.0–2.5 for extraction. The characteristics and physicochemical properties of gelatin were investigated. The results indicated that the gelatin had a high protein content (88.6–90.0%) with ash (1.43–1.55%) and no fat. The gelatin was identified as type A due to its pH value. The yields of gelatin were 14.1–15.2%. The gel strength and melting point were 270.3 g and 26.7°C, respectively, for gelatin from seabass scales and 249.1 g and 25.9°C, respectively, for samples from grey mullet scales. In contrast, the viscosities of gelatin were found to be 6.97 cP for seabass and 8.73 cP for grey mullet. Both gelatins contained α-chain and β-chain as the major components. Circular dichroism spectra indicated that the triple helical structure in collagen was almost transformed to the random coil structure in gelatin. The proportion of imino acids was high (197–205 residues/1,000 residues). So, gelatin from seabass and grey mullet scales could be used as a potential replacement for mammalian gelatin.

The identification of three mammalian gelatins by liquid chromatography-high resolution mass spectrometry

High-performance liquid chromatography (HPLC) and linear-ion trap (LTQ)/Orbitrap high-resolution mass spectrometry were combined to systematically differentiate three mammalian gelatins including bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin. Interestingly, hemoglobin was found only in the donkey-hide gelatin while not in bovine-hide gelatin and porcine-hide gelatin. In marker peptide determination for each individual gelatin, 28, 27 and 14 distinct peaks were detected to represent the bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin, respectively. In the gelatin mixtures, all gelatins can be differentiated by their marker peptides. However, the number of detectable marker peptides in each gelatin decreased with reduced concentration of target gelatin in their mixtures. Under low content of target gelatin (less than 10%), 11, 15 and 5 marker peptides were detected in the gelatin mixture digests for bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin, respectively. HPLC-LTQ/Orbitrap high-resolution mass spectrometry could be a promising technology to accurately identify bovine-hide gelatin, porcine-hide gelatin and donkey-hide gelatin for controlling the quality of food products added with gelatin.

EXTRACTION AND CHARACTERIZATION OF GELATIN: A FUNCTIONAL BIOPOLYMER

Objective: Gelatin is widely used biopolymer in various industries due to its excellent biocompatibility, biodegradability properties. In the present study, gelatin was extracted from fish wastes, as an alternative source.Methods: This biopolymer was extracted from the scales of freshwater fish, Labeo rohita. After extraction, the proximate analysis and physico-chemical analysis of the fish scale gelatin were carried out. This functional polymer was also characterized using different analytical methods, such as UV-vis spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) for the evaluation of crystalline and surface morphology, and fourier transform infrared spectroscopy (FTIR) for structural determination.Results: The scales of L. rohita yield 24% (dry weight basis) of gelatin, indicating this fish species as potential source of gelatin. The proximate analysis determined was low moisture content (4.2%), ash (1.4%) and high protein (90%) content. The result of the study confirms the effectiveness of extraction method used.Conclusion: The fish scales of L. rohita are found to be a sustainable and renewable source of gelatin with desirable functionalities and it is the best alternative for mammalian gelatin in food and other industries.

Nanostructural analysis and textural modification of tilapia fish gelatin affected by gellan and calcium chloride addition

Fish gelatin (FG) is more suitable for consumption by religious people than mammalian gelatin. One common modification method of FG is mixing FG with polysaccharides. However, the mechanism is not clear. We found that FG gel containing 0.1 g/100 mL gellan, 20 mmol/L CaCl2 and 6.67 g/100 mL FG (180 Bloom) matched gel strength, hardness, cohesiveness, chewiness as well as gelling temperature (Tg) and melting temperature (Tm) of commercial beef gelatin (BG) (240 Bloom). The modified FG was also observed by the result of helix/coil ratio and spherical aggregates. The modification decreased the diameter of FG's aggregates from 472 to 249 nm, which matched with BG (272 nm, P < 0.05). Co-existence of segregative gellan-gellan fibrous aggregates and associated FG-gellan amorphous structure were also identified at the modified FG by atomic force microscope (AFM). The helix/coil ratio and diameter of spherical aggregates were inversely correlated, the mechanism behind was the strength of gelatin association. The involvement of hydrogen bond and presence of FG-gellan complex have been validated by urea addition and Fourier transform infrared (FTIR) spectroscopy. A schematic model was proposed. As modified FG successfully matched the of texture properties of BG, it is promising to replace BG with FG.

Functional properties of gelatin extractd from skin of black kingfish (Rachycentron canadus) at 40 Degree C

The utilization of waste skin from fish for production of value added by-products has attracted substantial attention. Black kingfish ( Ranchycentron canadus ) is used for culinary purpose but their skin was waste part and convert into in value added product like gelatin is the good practice of post harvest management of waste utilization. In order to evaluate the waste from black kingfish as source of gelatin, the gelatin was from skin and its rheological and functional properties were examined at temperatures 40°C. The skin of Black Kingfish yielded 10.20 per cent indicating skin as an important source of gelatin production. The gel strength of gelatin skin (206.5g), viscosity (9.53 cP), melting point (21.76°C), water holding capacity (3.96 ml/g), pH (4.9), emulsifying capacity and stability (46.50%) and (28.53%), respectively obtained from extracted gelatin. The Hydroxyproline content in extracted gelatin was about (6.73mg/g). It can be concluded from the study that Black kingfish is prospective source to produce gelatin in good yield with desirable functional properties comparable to commercially available mammalian gelatin.

Fabrication of an ultrafine fish gelatin nanofibrous web from an aqueous solution by electrospinning

Electrospinning of aqueous gelatin solution obtained from bovine or porcine sources has been difficult to achieve without additional facilities, such as a temperature control oven or heating cover. Gelatin from cold-water fish has low contents of proline (Pro) and hydroxyproline (Hyp) compared with mammalian-derived gelatin. For this reason, the fish-derived gelatin maintains a sol state without showing gelation behavior at room temperature. In the present study, we prepared an ultrafine fish gelatin nanofibrous web by electrospinning from aqueous solutions without any additive polymers or temperature control facilities. The concentration and viscosity of fish gelatin are the most important factor in determining the electrospinnability and fiber diameter. Electrospinning of aqueous fish gelatin has the highest nanofiber productivity compared to other organic solvent systems. Using glutaraldehyde vapor (GTA), the water stability was improved and substantial enhancement was achieved in the mechanical properties. Finally, the cytotoxicity of a fish gelatin nanofibrous scaffold was evaluated based on a cell proliferation study by culturing human dermal fibroblasts (HDFs) compared with a fish gelatin film and nanofibrous mat from mammalian gelatin. The result shows better initial cell attachment and proliferation compared with the fish gelatin film and no significant difference compared with mammalian-derived gelatin nanofibrous mat. We expect that electrospinning of aqueous fish gelatin could be an effective alternative mammalian gelatin source.

Evaluation of tilapia skin gelatin as a mammalian gelatin replacer in acid milk gels and low-fat stirred yogurt

Tilapia skin gelatin (TSG) was studied in a 3-stage process (cooling, annealing, and heating) for pure gelatin gels and in a 4-stage process (acidification, cooling, annealing, and heating) for acid milk gels and cultured yogurt. The aim was to evaluate the use of TSG as a replacement for mammalian gelatin in yogurt. In pure TSG gels, stronger gels with higher melting temperatures were formed with increasing TSG concentrations. Compared with bovine gelatin (BG), which gelled at a concentration of 2.5%, TSG gels had lower gelling (14.1°C) and melting (24°C) temperatures but comparable storage moduli during annealing. In acid milk gels, addition of TSG increased the firmness of the gels with increasing concentration. Gelling and melting points of TSG in milk gels were observed at sufficient concentrations during cooling and heating. Strands and sheets were observed in the electron micrographs of milk gels with 1% TSG and a very dense structure was observed with 2.5% TSG. Yogurt with 0.4% TSG had similar viscosity, consistency, pseudoplasticity, and thixotropy as yogurt containing 0.4% BG; no difference was perceived by sensory panelists according to a triangle test. Addition of 0.4% TSG completely prevented whey separation from the acid milk gel and yogurt. The results suggest that TSG could be a suitable replacement for mammalian gelatin in low-fat stirred yogurt.

Extraction and characterization of gelatin from the feet of Pekin duck (Anas platyrhynchos domestica) as affected by acid, alkaline, and enzyme pretreatment

The effects of different pretreatments on yield and composition of extraction, physicochemical, and rheological properties of duck feet gelatin (DFG) were investigated. Gelatins were extracted from the whole feet of Pekin duck with an average yield of 4.09%, 3.65%, and 5.75% for acidic (Ac-DFG), alkaline (Al-DFG), and enzymatic (En-DFG) pretreatment on a wet weight basis, respectively. Proteins at 81.38%, 79.41%, 82.55%, and 87.38% were the major composition for Ac-DFG, Al-DFG, En-DFG, and bovine, respectively. Amino acid analysis showed glycine as the predominant amino acid in Ac-DFG, followed by hydroxyproline, proline, and alanine for Ac-DFG, Al-DFG, and En-DFG, respectively. Rheological analysis indicated that the maximum elastic modulus (9972.25Pa) and loss modulus (4956.28Pa) for Ac-DFG gelatin were significantly higher than those of other gelatins. Extracted gelatins contained α1 and α2 chains as the predominant components, and enzymatic gelatin had low molecular weight peptides. Fourier transform infrared spectroscopy showed that the peak of the gelatins was mainly positioned in the amide band region (amides I, II, and III). A considerable loss of molecular-order triple helical structure was also observed after pepsin treatment. In summary, duck feet gelatin has potential to replace as mammalian gelatin in food and pharmaceutical industry.

Poultry Processing Waste as an Alternative Source for Mammalian Gelatin: Extraction and Characterization of Gelatin from Chicken Feet Using Food Grade Acids

The present study was focused on extraction of gelatin from chicken feet using different food grade acids (acetic-, citric- and lactic-acid) at different concentrations. The gelatin thus obtained was evaluated for its physico-chemical properties. Gelatin yields in various acid treatments ranged between 6.18 and 14.47% on wet weight basis. The protein content of chicken feet gelatin (CFG) obtained with different acid treatments was in the range of 80.53–90.20%; while, the pH was in the range of 3.43–5.23. Among all, CFG extracted with 1.5% (v/v) acetic acid showed the highest bloom strength (204.3 g) which was similar to commercial porcine gelatin. The CFG prepared using 4.5% (v/v) citric acid had a bloom value of 165.8 g. The bloom strength of CFG prepared in our study was relatively higher than fish gelatin and slightly lower than porcine gelatin. Hydroxyproline content (g/100 g) of CFG prepared using different acids was in the range of 4.58–9.5. The CFG contained glycine (~30%), imino acids (proline + hydroxyl proline; ~25%) and alanine (~9%) as the major amino acids. CFG, irrespective of the acids used for preparation, exhibited moderate to strong emulsifying and foaming capacities. The results clearly indicate the potential of CFG to be an effective alternative to mammalian gelatin.

Uskumru (Scomber scombrus) ve Levrek (Dicentrarchus labrax ) Kemiklerinden Jelatin Ekstraksiyonu ve Karakterizasyonu

The aims of this study were to determine the physicochemical properties of extracted gelatins from mackerel (Scomber scombrus) and sea bass (Dicentrarchus labrax) bones and compare with those of commercial fish and bovine gelatins. The yield of gelatin obtained from the bone of mackerel and sea bass were 5.98 and 6.20%, respectively. Two extracted gelatins showed higher protein content, lower moisture content compared to both commercial gelatins, indicates that the gelatin has considerably high purity. Melting temperatures of mackerel and sea bass bone gelatins were 25.5 and 23°C, respectively. Mackerel bone gelatin was yellow in appearance and higher L* value than both commercial gelatins. It can be concluded from the present study that mackerel and sea bass bone are a prospective source to produce gelatin in good yield with desirable functional properties comparable to commercially available mammalian and fish gelatins.