Mammalian Gelatin Research Articles

Properties of Gelatin Film from Horse Mackerel (Trachurus japonicus) Scale

Optimal conditions for extracting gelatin and preparing gelatin film from horse mackerel scale, such as extraction temperature and time, as well as the protein concentration of film-forming solutions were investigated. Yields of extracted gelatin at 70 °C, 80 °C, and 90 °C for 15 min to 3 h were 1.08% to 3.45%, depending on the extraction conditions. Among the various extraction times and temperatures, the film from gelatin extracted at 70 °C for 1 h showed the highest tensile strength and elongation at break. Horse mackerel scale gelatin film showed the greatly low water vapor permeability (WVP) compared with mammalian or fish gelatin films, maybe due to its containing a slightly higher level of hydrophobic amino acids (total 653 residues per 1000 residues) than that of mammalian, cold-water fish and warm-water fish gelatins. Gelatin films from different preparation conditions showed excellent UV barrier properties at wavelength of 200 nm, although the films were transparent at visible wavelength. As a consequence, it can be suggested that gelatin film from horse mackerel scale extracted at 70 °C for 1 h can be applied to food packaging material due to its lowest WVP value and excellent UV barrier properties.

Fish Gelatin: Characteristics, Functional Properties, Applications and Future Potentials

Gelatin, an important biopolymer derived from collagen, is widely used by various industries because of its functional and technological properties. The vast majority of commercial gelatin is derived from mammals, but due to many sociocultural and religious reasons, there is an increasing demand for alternative sources. The by-products generated by the fish-processing industry are a potential source for the production of gelatin. The high potential of fish gelatin production is due to the large quantities of collagen by-products generated. However, the main restriction to its use regards their lower rheological properties when compared to mammalian gelatin, which limits its range of applications. This review discusses the latest scientific literature about the main characteristics and functional properties of fish gelatin, which shows the main strategies used to improve its properties, as well as its applications and future potentials.

Physicochemical Properties of Gelatin from Jellyfish Rhopilema hispidum

Abstract The objective of this study was to elucidate the physicochemical characteristics of gelatin extracted from jellyfish Rhopilema hispidum . We investigated the proximate composition, amino acids, gel strength, gelling/melting points, dynamic viscoelastic properties, and viscosity of jellyfish gelatin. Jellyfish gelatin contained 12.2% moisture, 1.5% lipid, 2.1% ash, and 84.8% protein. Glycine, hydroxyproline, proline, and alanine were the predominant amino acids. The gelatin showed a gel strength of 31.2 kPa, a gelling point of 18.0°C, and melting point of 22.3°C. The gelatin was composed of α 1 -chain, α 2 -chain, β-chain, and γ-chain. During cooling and heating process, jellyfish gelatin showed lower elastic modulus (G') and loss modulus (G'') values than mammalian gelatin. Jellyfish gelatin did not show superior rheological properties to mammalian gelatin, like other fish gelatin; however, it can be used in various food and cosmetic products not requiring high gel strength.

Extraction and Physicochemical Characterization of Gelatin from Chicken By‐Product

AbstractPhysicochemical properties of gelatin gels extracted from skins and tendons of chicken feet were characterized as an alternative to mammalian gelatin commonly used commercially. After extraction, the preparation of gels for analysis was made by dissolving the dry gelatin with two concentrations: 3.33 and 6.67% (w/w) in distilled water. The determination of gel strength and texture profile analysis was performed using texture analyzer. Gelatin showed high protein content and the value observed for gel strength was higher for the gelatin with concentration of 6.67% (294.78 g), classified as high bloom, while for the gelatin with concentration of 3.33% (96.47 g) was lower, low bloom. The hardness and chewiness increased significantly with increasing concentrations of gelatin and the gelatin with concentration (6.67%) behaved as a solid and it can be used in the preparation of gelatin gums, marshmallows, gelatin dessert among others that requiring high bloom.Practical ApplicationsThis research contributes to the knowledge about chicken feet gelatin from skin and tendons wastes, which can be an alternative to mammalian gelatin in the food industry making more effective use this underutilized resources. The collagen extraction provides a nobler destiny for chicken feet able to boost up the commercial values of these cheap and underutilized protein sources. This work also presents information not addressed on the gelatin from this raw material, such as parameters of texture profile and color, besides the specific characterization, considering the tissue and the extraction method used.

SENSITIZATION TO THE MAMMALIAN OLIGOSACCHARIDE GALACTOSE-ALPHA-1,3- GALACTOSE (ALPHA-GAL): EXPERIENCE IN A FLEMISH CASE SERIES

Background. Recent observations have disclosed that the galactose-α(1,3)-galactose (α-gal) moiety of non-primate glycoproteins can constitute a target for meat allergy.Objective. To describe adults with allergic reactions to mammalian meat, dairy products and gelatin. To investigate whether patients could demonstrate sensitization to activated recombinant human coagulation factor VII ectapog alpha that is produced in baby hamster kidney cells.Methods. Ten adults with mammalian meat, dairy products and gelatin allergies were examined using quantification of specific IgE and/or skin prick test for red meat, milk, milk components, gelatin, cetuximab and eptacog alpha.Results. Most patients demonstrate quite typical clinical histories and serological profiles, with anti-α-gal titers varying from less than 1% to over 25% of total serum IgE. All patients demonstrate negative sIgE for gelatin, except the patient with a genuine gelatin allergy. All patients also demonstrated a negative sIgE to recombinant milk components casein, lactalbumin and lactoglobulin. Specific IgE to eptacog was positive in 5 out of the 9 patients sensitized to α-gal and none of the 10 control individuals.Conclusion. This series confirms the importance of the α-gal carbohydrate moiety as a potential target for allergy to mammalian meat, dairy products and gelatin (oral, topical or parenteral) in a Flemish population of meat allergic adults. It also confirms in vitro tests to mammalian meat generally to be more reliable than mammalian meat skin tests, but that diagnosis can benefit from skin testing with cetuximab. Specific IgE to gelatin is far too insensitive to diagnose α-gal related gelatin allergy. IgE binding studies indicate a potential risk of α-gal-containing human recombinant proteins produced in mammalians.

Preparation and Properties on Gelatin from Fish Scale

The effect of solid-liquid ratio, pH, temperature, time on yield and gel strength of gelatin from fish scale was researched. The best process was obtained. That was solid-liquid ratio1:15, pH5.5, temperature 80°C, time 2h. In this condition, yield of gelatin was 55.782%, and gel strength was 571g. In addition, properties were compared between fish gelatin and mammalian gelatin. The results showed gel strength, foaming ability and water absorption of fish gelatin were better than mammalian gelatin. The emulsifying properties of fish gelatin were worse than mammalian gelatin. Foaming stability and water retention of fish gelatin were almost the same with mammalian gelatin.

Optimization of process parameters for gelatin extraction from the skin of Blackspotted croaker using response surface methodology.

Utilization of waste from fish processing industry for production of value added products has attracted substantial attention. Blackspotted croaker (Protonibea diacanthus) is a marine fish having the potential of abundant supply of raw skins for production of gelatin. This study was aimed to optimize the extraction conditions for gelatin production from skin of Blackspotted croaker. Response surface methodology (RSM) was adopted by following central composite design to determine the optimal conditions of four independent variables namely concentration of NaOH (X1), soaking time (X2), extraction temperature (X3) and extraction time (X4) for three response variables namely yield, gel strength and melting point. The models obtained by RSM produced a satisfactory fit to the data with respect to gelatin extraction (for gelatin yield, R (2) = 0.867, P = 0.0003; for gel strength, R (2) = 0.837, P = 0.007; for melting point, R (2) = 0.765, P = 0.01). Based on these models, the optimum conditions to achieve the predicted maximum values were: yield of 17.21% at X1 = 0.23%, X2 = 46.19min, X3 = 55.29°C and X4 = 17.29h; gel strength of 422.69g at X1 = 0.22%, X2 = 44.56min, X3 = 59.02°C and X4 = 15.35h and melting point of 23.48°C at X1 = 0.20%, X2 = 46.68min, X3 = 56.23°C and X4 = 15.21h. It can be concluded from the present study that Blackspotted croaker skin is a prospective source to produce gelatin in good yield with desirable quality attributes comparable to commercially available mammalian gelatins.

Comparison of the properties of multi-composite fish gelatin films with that of mammalian gelatin films

Four types of films viz. gelatin, gelatin–MMT, gelatin–chitosan and gelatin–MMT–chitosan prepared from redsnapper and grouper bone gelatin were compared with the mammalian gelatin films, for their mechanical and barrier properties. Grouper gelatin films had higher tensile strength (TS) and Young’s modulus (YM), but lower elongation at break (EAB) than redsnapper films. Incorporation of MMT and chitosan improved the TS (p<0.05) of the films. Water solubilities were lower (p<0.05) in films incorporated with chitosan compared to simple gelatin film. Protein solubilities were lower in gelatin–MMT films, irrespective of the type of solvent used. The water vapour transmission rates (WVTR) of fish and mammalian gelatin films were similar, but addition of MMT had reduced WVTR (p<0.05). SEM micrographs depicted smoother surface for gelatin–MMT and gelatin–MMT–chitosan films. Thus, composite fish gelatin films made with MMT and chitosan could be the good natural biodegradable films due to their better mechanical and barrier properties.

Preparation and characterisation of chicken skin gelatin as an alternative to mammalian gelatin

The aims of this study were to report for the first time, the extraction and physico-chemical properties of chicken skin gelatin compared to bovine gelatin. Extracted chicken skin gelatin 6.67% (w/v) had a higher bloom value (355 ± 1.48 g) than bovine gelatin (259 ± 0.71 g). The dynamic viscoelastic profile of chicken gelatin exhibited higher viscous and elastic modulus values compared to bovine gelatin for a range of concentrations and frequencies. Thermal properties studied by differential scanning calorimetry (DSC) showed that the melting temperature of 6.67%, chicken skin gelatin was significantly greater (p < 0.05) than that of bovine gelatin, indicating lower stability of bovine gelatin compared to chicken skin gelatin. Results obtained in this study showed that Gly (33.70%), Pro (13.42%), H.Pro (12.13%) and Ala (10.08%) were the most dominant amino acids in chicken skin gelatin which contributed to the higher gel strength and stability. Raman spectra of chicken skin and bovine gelatin were similar and displayed typical protein spectra. Chicken gelatin showed strong hydrogen bonding compared to bovine gelatin as the tyrosine doublet ratio (I855/I830) of chicken gelatin was significantly lower than that of bovine gelatin. Significantly, the alpha helix and β-sheet type structures were higher for chicken skin gelatin compared with bovine gelatin. The average molecular weight of chicken gelatin was 285,000 Da. These findings, obtained for the first time for chicken skin gelatin, show that it has high potential for application as an alternative to commercial gelatin.

Enhancement of Functional Properties of Wami Tilapia (Oreochromis urolepis hornorum) Skin Gelatin at Different pH Values

The effects of several agents in two different concentrations and pH values (5.0 and 8.0) on the functional properties of tilapia (Oreochromis urolepis hornorum) skin gelatin were evaluated and compared using a control tilapia skin gelatin and a commercial mammalian gelatin. The addition of the agents (sucrose 4 % and 8 % (w/v), glycerol 5 % and 10 % (v/v), NaCl 0.3 and 0.8 mol/L, MgCl2 0.3 and 0.8 mol/L, MgSO4 0.3 and 0.8 mol/L, KCl 0.3 and 0.8 mol/L, and transglutaminase 10 and 15 mg/mL) slightly increased the turbidity. There were different ratios of rheological properties depending on the agent, concentration, and pH. The addition of all agents increased the viscosity of the gelatin solution, mainly at pH 5.0. The addition of glycerol (10 % (v/v)) raised viscosity up to 7.45 cP. The setting time was prolonged by incorporating the agents. The gelatin samples with the addition of MgSO4 0.8 mol/L showed higher gel strength than the mammalian gelatin, exhibiting values of 298 and 295gf at pH 5.0 and 8.0, respectively.

A comparative study on the physical, chemical and functional properties of carp skin and mammalian gelatins.

Carp species forms the bulk of the aquaculture production in India and studies have shown that the filleting waste of these species, particularly skin can be a good source of gelatin. This study is a comparison of the gelatins from these unexploited sources with that of mammalian gelatins to get a better understanding of their physicochemical and functional properties with respect to mammalian gelatins. The study showed that mammalian gelatins had significantly superior physical properties viz., higher viscosity, melting & setting temperature and faster setting time. The odour scores were significantly higher (P < 0.05) for bovine and porcine skin gelatins (3.1-3.12), indicating that they had a distinguishable odour and hence can be considered as inferior to fish skin gelatins in organoleptic qualities. The gel strengths of rohu and common carp skin gelatins were significantly lower than mammalian gelatins. Among the carp skin gelatins, grass carp skin gelatin was found to have better compatibility with gelatin from bovine and porcine skins.

Functional characterization of gelatin extracted from bones of red snapper and grouper in comparison with mammalian gelatin

The average yields of fish gelatin extracted from the bones of red snapper (Lutjanus campechanus) and grouper (Epinephelus chlorostigma) were 9.14 and 13.66 g/100 g, respectively. The protein contents of the bone gelatin ranged from 78.5 to 82.36 g/100 g. The pH of the extracted gelatins were acidic (pH 4.3–4.6) with an absorption maxima at 214 nm. The viscosities were higher than mammalian gelatin with values 13–18 cP. Melting temperatures were higher (26 °C) and gelling temperature were lower (16 °C) than that of mammalian gelatin with 21 °C, 22 °C respectively. The bloom strengths were comparable with mammalian gelatin with values of 7.5–7.7 N. In fish gelatin, foaming abilities/stabilities and fat binding capacity (FBC) were higher than mammalian gelatin. The water holding capacity of grouper bone gelatin being similar to mammalian gelatin. SDS protein-patterns of the bone gelatins of two species did not show variations. The α, β and γ chains showed that the triple helical structure were not totally destroyed in the fish gelatin. The physical and functional properties for fish bone gelatin suggested that their qualities were similar to mammalian gelatin and suitable for the food and packaging applications.

Towards producing novel fish gelatin films by combination treatments of ultraviolet radiation and sugars (ribose and lactose) as cross-linking agents.

Developing novel fish gelatin films with better mechanical properties than mammalian gelatin is a challenging but promising endeavor. Studies were undertaken to produce fish gelatin films by combining treatments with different sugars (ribose and lactose) followed 'by' 'and' ultraviolet (UV) radiation, as possible cross-linking agents. Increase in tensile strength and percent elongation at break was recorded, which was more significant in films without sugars that were exposed to UV radiation. Films with added ribose showed decreased solubility after UV treatment and exhibited higher swelling percentage than films with added lactose, which readily dissolved in water. FTIR spectra of all the films showed identical patterns, which indicated no major changes to have occurred in the functional groups as a result of interaction between gelatin, sugars and UV irradiation. The results of this study could be explored for commercial use, depending on industrial needs for either production of edible films or for food packaging purposes.

Gelation, Oxygen Permeability, and Mechanical Properties of Mammalian and Fish Gelatin Films

The objective of this study was to evaluate the gelation, thermal, mechanical, and oxygen permeability properties of different mammalian, warm- and cold-water fish gelatin solutions and films. Mammalian gelatin solutions had the highest gel set temperatures, followed by warm-water fish and then cold-water fish gelatin solutions. These differences were related to concentrations of imino acids present in each gelatin, with mammalian gelatin having the highest and cold-water fish gelatin having the lowest concentrations. Mammalian and warm-water fish gelatin films contained helical structures, whereas cold-water fish gelatin films were amorphous. This was due to the films being dried at room temperature (23 °C), which was below or near the gelation temperatures of mammalian and warm-water fish gelatin solutions and well above the gelation temperature of cold-water fish gelatin solutions. Tensile strength, percent elongation, and puncture deformation were highest in mammalian gelatin films, followed by warm-water fish gelatin film and then by cold-water fish gelatin films. Oxygen permeability values of cold-water fish gelatin films were significantly lower than those for mammalian gelatin films. These differences were most likely due to higher moisture sorption in mammalian gelatin films, leading to higher oxygen diffusivity.

Functional characteristics of gelatin extracted from skin and bone of Tiger-toothed croaker (Otolithes ruber) and Pink perch (Nemipterus japonicus)

The utilization of waste from fish processing industry for production of value added products has attracted substantial attention. Tiger-toothed croaker (Otolithes ruber) and Pink perch (Nemipterus japonicus) are used for surimi production and have the potential of abundant supply of raw skins and bones. In order to evaluate the waste from Tiger-toothed croaker and Pink perch as a source of gelatin, the gelatin was extracted from skin and bones and its rheological and functional properties were examined. The skins of Tiger-toothed croaker and Pink perch yielded 7.56% and 5.57% gelatin, whereas their bones yielded 4.57% and 3.55% respectively indicating skin as an important source for gelatin production. The gel strength of gelatins from the skins and bones of Tiger-toothed croaker (170g and 140g respectively) were found higher than Pink perch skin and bone gelatins (150g and 130g respectively). Similarly, the viscosity, melting point, emulsifying capacity and stability, foaming capacity and stability, and water holding capacity of gelatin extracted from Tiger-toothed croaker were in general greater than those of the gelatin from Pink perch and the values of skin gelatin were higher compared to bone gelatin in both the species. Hydroxyproline contents in skin and bone of Tiger-toothed croaker were 7.77 and 7.51mg/g and in Pink perch they were 7.63 and 7.41mg/g respectively. It can be concluded from the present study that Tiger-toothed croaker skin is a prospective source to produce gelatin in good yield with desirable functional properties comparable to commercially available mammalian gelatins.

Improvement of Gel Strength and Melting Point of Fish Gelatin by Addition of Coenhancers Using Response Surface Methodology

Fish gelatin is a potential alternative to mammalian gelatin. However, poor gel strength and low melting point limit its applications. The study was aimed at improving these properties by adding coenhancers in the range obtained from response surface methodology (RSM) by using Box-Behnken design. Three different coenhancers, MgSO₄, sucrose, and transglutaminase were used as the independent variables for improving the gel strength and melting point of gelatin extracted from Tiger-toothed croaker (Otolithes ruber). Addition of coenhancers at different combinations resulted gel strength and melting point in the range of 150.5 to 240.5 g and 19.5 to 22.5 °C, respectively. The optimal concentrations of coenhancers for predicted maximum gel strength (242.8 g) obtained by RSM were 0.23 M MgSO₄, 12.60% sucrose (w/v), and 5.92 mg/g transglutaminase and for predicted maximum melting point (22.57 °C), the values were 0.24 M MgSO₄, 10.44% sucrose (w/v), and 5.72 mg/g transglutaminase. By addition of coenhancers at these optimal concentrations in verification experiments, the gel strength and melting point were improved from 170 to 240.89 g and 20.3 to 22.7 °C, respectively. These experimental values agreed well with the predicted values demonstrating the fitness of the models. Results from the present study clearly revealed that the addition of coenhancers at a particular combination can improve the gel strength and melting point of fish gelatin to enhance its range of applications. There is a growing interest in the use of fish gelatin as an alternative to mammalian gelatin. However, poor gel strength and low melting point of fish gelatin have limited its commercial applications. The gel strength and melting point of fish gelatin can be increased by incorporation of coenhancers such as magnesium sulphate, sucrose, and transglutaminase. Results of this work help to produce the fish gelatin suitable for wide range of applications in the food industry.

Thermal characteristics of gelatin extracted from shaari fish skin

Gelatin extraction yield increased with the increase of acetic acid concentration and temperature. Gelatin extracted from shaari skin using 0.1 N acid solutions and temperatures of 323 and 353 K gave highest protein content comparable to that of commercial bovine and porcine gelatins. In general, gelatin extracted from shaari gelatin showed lower onset of glass transition temperature than mammalian gelatins. For shaari skin gelatin, the onset of glass transition temperature decreased with the increase of extraction temperature up to 323 K and then remained nearly constant. The decrease in glass transition was more pronounced for gelatin extracted at 0.01 N compared to the 0.1 and 1.0 N samples. Unfolding temperature decreased exponentially with the increase of extraction temperature. The unfolding temperature shifted to lower temperature, and the decrease was more pronounced in the case of higher (1.0 N) concentrated samples. The extraction concentration and temperature did not show significant effect on the onset solids-melting temperature.

Physical, Mechanical, and Barrier Properties of Carp and Mammalian Skin Gelatin Films

Films of 0.11 to 0.13 mm thickness were prepared using gelatins from the skins of cultured freshwater carp species and mammalian gelatins viz., porcine and bovine skin gelatin. A comparative study was made on the physical, mechanical, and barrier properties of these films. The amino acid composition, gel strength, clarity, and gel setting point of the gelatins were also determined. Carp skin gelatins had a lower imino acid content (19.16% to 20.86%) than mammalian skin gelatins (22.91% to 23.7%). Grass carp gelatin had gel strength of 230.2 B that is comparable to the reported value for bovine skin gelatin (227.2 B). The bloom values of rohu and common carp skin gelatins were 188.6 B and 181.3 B, respectively, which were significantly lower than mammalian gelatins. Mammalian gels have significantly higher (P < 0.05) setting temperatures (23.7 to 24.2 °C) than carp skin gelatins. Tensile strength (TS) was lowest for films from common carp and rohu skin gelatin (490 and 497 kg/cm(2), respectively) and highest for porcine skin gelatin film. The degree of transparency (L*) was significantly higher for films from grass carp, bovine hide, and pork skin gelatin films. Carp skin gelatin films had significantly lower water vapor permeability (WVP) and oxygen permeability (OP) than mammalian skin gelatin films, which indicated that carp skin gelatin based films have superior barrier properties than mammalian skin gelatin films.

Optimization of Hydrolysis Conditions for the Production of Antioxidant Peptides from Fish Gelatin Using Response Surface Methodology

Fish skin gelatin was hydrolyzed with papain to produce antioxidant peptides. Response surface methodology (RSM) was applied to optimize the hydrolysis conditions (including enzyme to substrate ratio [E/S], hydrolysis time, and temperature). The highest degree of hydrolysis (DH) (50.1 +/- 1.1%) was obtained at an E/S of 2% at 56.8 degrees C, 2.11 h, and was not significantly different from the predicted values within a 95% confidence interval. The highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) (96.8 +/- 0.9%) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS(*+)) (9.80 +/- 0.11 mM Trolox [6-hydroxy-2,5,7,8-tetramethychroman-2-carboxylic acid]) radical-scavenging activities of fish gelatin hydrolyzates were obtained at an E/S of 3% at 52.1 degrees C, 2.65 h, and both DPPH and ABTS(*+) radical-scavenging activities were not significantly different from the predicted values 97.3% and 9.86 mM Trolox within the 95% confidence interval. Therefore, RSM is an efficient way to optimize fish gelatin hydrolysation and the resultant hydrolyzates show promise as antioxidant peptides. Practical Application: There is a growing interest in the use of fish gelatin as an alternative to mammalian gelatin. One potential use is as a source of widely acceptable functional compounds. In this study, a search for antioxidant peptides from fish gelatin prepared by an enzymatic method has been successfully done. This suggests that this is a practical way to obtain bioactive peptides.

Physicochemical Properties of Mammalian Gelatin in Relation to Membrane Process Requirement

In any of the membrane process application, understanding of the characteristics of the feed solution is essential in order to achieve desired level of separation performance. In this study, in an effort to substitute evaporation with membrane processes partially, experiments were carried out to investigate the physicochemical properties of gelatins, namely, molecular weight distribution, pH, viscosity, isoelectric point, and gel strength, which are, of foremost, important parameters in the characterization of gelatin. Two different mammalian gelatins, i.e. from bovine (type B) and porcine (type A) sources, were used in this study. The pH was significantly varied for all gelatins in the vicinity of 4.75–5.51 (±0.01). Experimental result revealed that both sources of mammalian gelatin contained components of different molecular weights with wide distribution ranging from 10 to 400 kDa. Analysis of the molecular weight distribution result also showed strong correlation between average molecular weight and gel strength of gelatin. The isoelectric points of gelatins from bovine were 4.60 ± 0.08 to 5.25 ± 0.43 and porcine gelatins were in the range of 7–9.3, which agreed well with the results obtained from other researchers. The high bloom strength mammalian gelatins were also significantly more viscous and thus, had a higher melting point.