Yields Of Pepsin Soluble Collagen Research Articles

Effect of Extraction Time on the Extractability and Physicochemical Properties of Pepsin—Soluble Collagen (PCS) from the Skin of Silver Catfish (Pangasius sp.)

The current study aimed to determine the effects of extraction time on the extractability and physicochemical properties of collagen from the skin of silver catfish (Pangasius sp.). Pepsin soluble collagen (PSC) was extracted for 24 and 48 h and analysed in terms of chemical composition, solubility, functional group, microstructure, and rheological properties. The yields of PSC at 24 h and 48 h extraction time were 23.64% and 26.43%, respectively. The chemical composition exhibited significant differences, with PSC extracted at 24 h showing better moisture, protein, fat, and ash content. Both collagen extractions indicated the highest solubility at pH 5. In addition, both collagen extractions exhibited Amide A, I, II, and III as fingerprint regions for collagen structure. The morphology of the extracted collagen appeared porous with a fibril structure. The dynamic viscoelastic measurements of complex viscosity (η*) and loss tangent (tan δ) decreased as temperature increased, and the viscosity increased exponentially as the frequency increased, whereas the loss tangent decreased. In conclusion, PSC extracted at 24 h showed similar extractability to that extracted at 48 h but with a better chemical composition and shorter extraction time. Therefore, 24 h is the best extraction time for PSC from silver catfish skin.

Extraction of collagen-II with pepsin and ultrasound treatment from chicken sternal cartilage; physicochemical and functional properties.

A simple and green approach was developed to extract the pepsin soluble collagen-II using the ultra-sonication treatment that significantly increased the extracted yield from chicken sternal cartilage (CSC). The pretreatment of raw CSC had positive effects on proximate composition. The maximum yield of pepsin soluble collagen was obtained by ultrasound treatment time 36min (UPSCII36; 3.37g) as compared to non-ultrasound treated pepsin soluble collagen at zero minutes (UPSCII0; 1.73g) (control). The amino acid profile, differential scanning calorimetry (DSC) of UPSC were significantly (p<0.05) improved by the application of ultrasound. The results showed the secondary structure of ultrasound treated PSC-II was partially altered as the ultra-sonication time prolonged. Moreover, ultrasound-treated collagen had superior functional properties such as water, oil absorption capacity, water holding capacity, foaming and emulsifying properties than non-ultrasound treated collagen. The poultry by-products CSC would be a potential source of land animal collagen-II. The utilization of ultrasound for the extraction of pepsin soluble collagen-II is a good alternative technology to expand the application of collagen at industrial level.

Characterization of marine derived collagen extracted from the by-products of bigeye tuna (Thunnus obesus)

Fish collagen is gaining immense interest because the use of mammalian collagen is restricted due to disease transmission and religious issues. So, collagen was extracted and characterized from three different parts (skin, scale, and bone) of bigeye tuna using the acid and pepsin extraction methods. The yield of acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) in skin were 13.5 ± 0.6% and 16.7 ± 0.7%, respectively, on a dry basis. The yields of PSC in scale and bone were 4.6 ± 0.3% and 2.6 ± 0.3%, respectively, while ASCs were in negligible amount. All the extracted collagens were type I collagen and a high level of imino acids (227–232/1000 residues) was found in all the extracted collagens. The thermal transition temperature (31.6–33.7 °C) and thermal denaturation temperature (31.1–32.2 °C) were higher than those of many temperate- and cold-water fish collagens. All collagens were highly soluble at acidic pH. The isoelectric points were 6.1, 6.4, 5.4, and 5.5 for skin-ASC, skin-PSC, scale-PSC, and bone-PSC, respectively. Therefore, the high collagen contents, especially in the skin, and higher thermal properties of the extracted collagens suggested that they have great potential for use as an alternate for mammalian collagen.

Isolation and characterisation of acid- and pepsin-soluble collagen from the skin of Cervus korean TEMMINCK var. mantchuricus Swinhoe

Acid-soluble collagen and pepsin-soluble collagen were extracted from the skin of deer, Cervus korean TEMMINCK var. mantchuricus Swinhoe. The two types of collagen were then characterised using sodium dodecyl sulfate–polyacrylamide gel electrophoresis, amino acid composition analysis, peptide hydrolysis patterns, thermal denaturation temperature, differential scanning calorimetry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance imaging. The yield of pepsin-soluble collagen (9.62%) was greater than that of acid-soluble collagen (2.24%), but both types of collagen showed similar electrophoretic patterns with each other and with calf skin collagen. The peptide hydrolysis pattern results suggested that calf skin collagen and pepsin-soluble collagen from deer skin may be similar in terms of their primary structure. The thermal denaturation temperature of acid-soluble collagen and pepsin-soluble collagen were 36.67°C and 36.44°C, respectively, and their melting temperatures were 110°C and 120°C, respectively, which suggest high thermal stability. Fourier transform infrared showed a triple helical structure and nuclear magnetic resonance confirmed the presence of ‘hydration’ water. These results provide a basis for large-scale production and further application as alternatives to other mammalian collagens.

A hybrid of back propagation neural network and genetic algorithm for optimization of collagen extraction from Malaysian cultured catfish (Hybrid Clarias sp.)

Fractional factorial design (FFD) was applied to evaluate the effects of various process parameters in influencing the extraction efficiency of pepsin soluble collagen (PSC) from muscles of cultured catfish (Clarias gariepinus×C. macrocephalus). Result of the first order factorial design showed that acetic acid concentration, acid extraction time, acetic acid to muscles ratio, and stirring speed posed significant effect (P<0.05) on the yield of PSC obtained at the end of the extraction process. Two different artificial intelligence techniques namely artificial neural network (ANN) and genetic algorithm (GA) were then integrated for optimizing the extraction conditions to obtain the highest yield of PSC. The ANN was trained using the back propagation algorithm. A model was successfully generated with R 2 value of 0.9527 and MSE value of 0.1672 for unseen data set, implying a good generalization of the network. Input parameters of the established ANN model were subsequently optimized using GA. The hybrid of ANN-GA model predicted a maximum extraction yield of PSC at 238.25 mg/g under the following conditions: an acetic acid concentration of 0.70 M, the acetic acid to muscles ratio of 25.78 mL/g, and the stirring speed of 432.50 rpm. Verification of the optimization showed the percentage error differences between the experimental and predicted values were less than 5%, indicating excellent modeling, predicting ability and optimization by the ANN-GA model.

Extraction, structural and physical characterization of type I collagen from the outer skin of Sepiella inermis (Orbigny, 1848)

The acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were extracted from the outer skin of Sepiella inermis and further characterized partially. The yield of ASC was low (0.58% on dry weight basis); whereas the yield of PSC was comparatively more (16.23% on dry weight basis). The protein content in ASC and PSC was calculated as 20.24 and 69.56%, respectively (on dry weight basis). The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel profile showed two bands for ASC and PSC with corresponding molecular weight of 86 and 67 kDa and 86, 63 and 58 kDa respectively. The differential scanning calorimetry (DSC) results showed that ASC withstand up to 75.93°C whereas the PSC withstand up to 75.05°C. The fourier transform infrared spectroscopy (FT-IR) spectrum of both ASC and PSC recorded 11 and 13 peaks, respectively. The fine structure of both ASC and PSC was also studied using scanning electron microscopy (SEM). Key words: Sepiella inermis, acid soluble collagen (ASC), pepsin soluble collagen (PSC), differential scanning calorimetry (DSC), fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM).

Extraction, structural and physical characterization of type I collagen from the outer skin of Sepiella inermis (Orbigny, 1848)

The acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were extracted from the outer skin of Sepiella inermis and further characterized partially. The yield of ASC was low (0.58% on dry weight basis); whereas the yield of PSC was comparatively more (16.23% on dry weight basis). The protein content in ASC and PSC was calculated as 20.24 and 69.56%, respectively (on dry weight basis). The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel profile showed two bands for ASC and PSC with corresponding molecular weight of 86 and 67 kDa and 86, 63 and 58 kDa respectively. The differential scanning calorimetry (DSC) results showed that ASC withstand up to 75.93°C whereas the PSC withstand up to 75.05°C. The fourier transform infrared spectroscopy (FT-IR) spectrum of both ASC and PSC recorded 11 and 13 peaks, respectively. The fine structure of both ASC and PSC was also studied using scanning electron microscopy (SEM). Key words: Sepiella inermis, acid soluble collagen (ASC), pepsin soluble collagen (PSC), differential scanning calorimetry (DSC), fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM).

Characterization of acid- and pepsin-soluble collagens from flatfish skin

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from flatfish skin were characterized. The yield of PSC was 85.5%, which was higher than that of ASC at 57.3%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns showed that both the ASC and PSC were consisted of α1 and α2 chains, and β-chain. According to the results of Fourier transform infrared (FTIR) spectroscopy and hydroxylation, no difference in the helical structure between ASC and PSC was found. Thermal denaturation temperature (TDT) of flatfish skin collagen was 26.6°C for ASC and 26.7°C for PSC, which were similar to those of temperate fishes, while were lower compared to tropical fishes, such as the conger eel and Nile perch. There was no solubility difference between ASC and PSC at various pH and NaCl concentrations. Therefore, PSC will be preferable compared to ASC for commercial uses because of its higher yield.

Characterization of Acid- and Pepsin-soluble Collagens from Rockfish Sebastes schlegeli Skin

Biochemical and functional properties of acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from rockfish skin were characterized. Yield of PSC (90.0%) was higher than that of ASC (63.2%). Both ASC and the PSC consisted of <TEX>${\alpha}1$</TEX> and <TEX>${\alpha}2$</TEX> chains, and <TEX>$\alpha$</TEX>-cross-linked components. According to the results of hydroxylation of proline and lysine, and FT-IR, no difference between the helical structure of ASC and PSC was identified. Thermal denaturation temperature (TDT) of ASC from rockfish skin was <TEX>$22.8^{\circ}C$</TEX>, the same as exhibited in PSC. Both ASC and PSC were higher in water absorption capacity (WAC) and oil absorption capacity (OAC) than other vegetable proteins. According to the results of emulsifying activity (EA) and cooking stability (CS), both ASC and PSC from rockfish skin were inferior compared to the commercial emulsifier (Tween-80). The results of FT-IR suggested that the structure of PSC was slightly different when compared to that of ASC. No differences in solubility were established between ASC and PSC from rockfish skin at various pH and NaCl concentrations.