EXTRACTION OF ACID‐SOLUBLE COLLAGEN FROM GRASS CARP (CTENOPHARYNGODON IDELLA) SKIN

Abstract

Grass carp is a freshwater fish species widely known by consumers over the world. Its skin has abundant collagen which has many healthy effects. Four variables (acetic acid concentration, temperature, time, solvent to material ratio) were taken to investigate their effects on the extraction efficiency of collagen from grass carp skin. From the results obtained, each of them showed a significant role in the extraction. The yield of collagen increased with the increase of acetic acid concentration to 0.5 M, and thereafter decreased. Elevation of temperature during extraction could also lead to the increase of collagen yield. However, when the temperature was above 20C, a negative effect was observed. The yield of collagen increased with the extension of time, especially when the time was shorter than 24 h. A positive relation was also observed between solvent to material ratio and yield of collagen. PRACTICAL APPLICATIONS Grass carp is widely consumed over the world for its delicious taste and healthy effect. A large amount of collagen exists in the skin tissues. Development of collagen from grass carp skin can bring added value for the fish processing industry. In this work, extraction of collagen from grass carp skin was investigated and effects of acetic acid concentration, temperature, time and solvent to material ratio on the extraction efficiency were determined. The results indicated that the above variables were influential for the extraction process. It is important to define the level of these variables in practical application so that the extraction efficiency can be improved, and a time‐saving, cost‐efficient process can be obtained.

Collagen Extraction from Malaysian Cultured Catfish (Hybrid Clarias Sp.): Kinetics and Optimization of Extraction Conditions Using Response Surface Methodology

“…This was probably due to lower initial solubility of collagen in the solvent with the increasing amount of solvent used. Even though there were claims that at higher solvent to material ratio, the concentration gradient and diffusion rate of solute into solvent could be enhanced [23], but in this case, the decrease in the initial extraction rate could be due to the lesser contact between the fish muscles with the acidic solvent. This was because stirring speed of the extraction process was set constant even though the amount of solvent used was increased.…”

“…Hence, the modification of the electrostatic interaction and structure of proteins might occur along the changes in acid concentration since pH value was in charge of the charge density of protein [22]. In fact, Wang et al [23] recently stipulated that more positively charged amine groups of collagen were resulted at the pH when the concentration of acetic acid used was at 0.5 M, leading to the highest yield among the studied concentrations. Denaturation of collagen at extremely low pH value (pH < 2) however was also another possibility that lower yield was observed when acetic acid with concentration more than 0.5 M was utilized.…”

“…The ratio was varied from 20 to 30 mL/g, but when it was raised to more than 25 mL/g, the improvement in the yield of PSC was no longer significant. Even though this phenomenon was not so obvious in , higher solvent to material ratio increases the concentration gradient and diffusion rate of collagen particles from the fish muscles into acetic acid, thus enhancing the efficiency of extraction process [23]. Nevertheless using a large amount of solvent is not cost effective due to a higher operating cost of solvent and waste handling at the end of the extraction process.…”

Acid‐soluble and pepsin‐soluble collagens from grass carp (Ctenopharyngodon idella) skin: a comparative study on physicochemical properties

“…As one of the largest members of the minnow family, the grass carp is a freshwater and herbivorous species with moderately large scales, native to southeastern Russia and China. It was originally introduced to United States, Europe and South America for the cost-effective control of aquatic plants and submerged grasses in aquaculture farms, lakes and rivers with long-term impact 30 years ago (Pipalova, 2006;Wang et al, 2009). As the flaky white meat of grass carp is rich in unsaturated fatty acids and selenium, it is beneficial to human health (Yang et al, 2014).…”

Screening and Empirical Kinetic Models of Collagen Extraction from Selected Malaysian Freshwater Fish

“…2011). Each polypeptide chain is characterized by the repeating structure of triplet (Gly‐X‐Y) n , where glycine residue is the structural prerequisite for the triple helix (Wang et al . 2009), while X and Y are often proline (Pro) and hydroxyproline (Hpy), respectively (Senaratne et al .…”