Extraction of Collagen from the Skin of Kacang Goat and Production of Its Hydrolysate as an Inhibitor of Angiotensin Converting Enzyme

Abstract

The study was designed to determine the potential of collagen hydrolysate produced from the skin of Kacang goat through chymotrypsin hydrolysis to be used as an inhibitor of angiotensin converting enzyme (ACE). This research was conducted in three replications, with the measured parameters include ACE inhibitory potential and collagen hydrolysate fractionation. The results showed that collagen extraction of Kacang goat skin by chymotrypsin hydrolysis yielded 9.74% (dry matter, v/v) collagen, with pH at 6.6. The extracted collagen contained α1, α2, and β collagen chains with molecular weights of 151 kDa, 141 kDa, and 240 kDa, respectively. Furthermore, the collagen hydrolysis produced protein peptides confirmed at molecular weights of 43 to 107 kDa. The hydrolysate fractionation at molecular weights of <3 kDa, 3-5 kDa, and >5 kDa showed proteins concentrations of 2.33 mg/mL, 3.81 mg/mL, and 3.93 mg/mL, respectively. The hydrolysate fractionation with molecular weight <3 kDa showed to have ACE inhibition activity with the IC50 value of 0.47 mg/mL. The study concluded that collagen hydrolysate extracted from the skin of Kacang goat had a promising potential as a source of antihypertensive agent.

Collagen Extraction from Animal Skin

“…For example, skins with fur and feathers may require different pretreatments. Mechanical slicing may be used to remove some of the fat adhering to the hide [ 20 , 54 , 55 , 56 , 57 , 58 ]. Alcohols such as butyl alcohol may be used to solubilize fat and pigments from chicken [ 55 , 56 ] and bovine skins [ 52 , 53 , 59 , 60 ].…”

“…Mechanical slicing may be used to remove some of the fat adhering to the hide [ 20 , 54 , 55 , 56 , 57 , 58 ]. Alcohols such as butyl alcohol may be used to solubilize fat and pigments from chicken [ 55 , 56 ] and bovine skins [ 52 , 53 , 59 , 60 ]. Other pretreatment steps may use heating [ 61 , 62 ], detergents [ 63 ], solvents such as petroleum ether [ 64 , 65 ], hexane [ 66 ], and hot water rinses [ 67 ].…”

“…The organic acids commonly used are acetic, chloroacetic, citric and lactic acids. Acetic acid has been widely reported for collagen extraction [ 16 , 48 , 50 , 54 , 55 , 56 , 59 , 71 , 72 ]. Among inorganic acids, the commonly used ones include hydrochloric, sulfuric and nitric acids [ 8 , 38 , 72 , 73 ].…”

“…A two-step extraction process without a preceding treatment has been reported for recovery of collagen from sheepskin; an enzymatic step was used first and this was followed by acid hydrolysis [ 79 ]. Another hybrid extraction procedure using acetic acid in combination with pepsin has been described by several authors [ 55 , 56 , 59 , 60 , 62 , 68 , 80 , 81 , 82 , 83 , 84 ].…”

“…Salts are most often used to achieve this, with a salt concentration exceeding 1.0 kmol m −3 . This treatment has been used for collagen from chicken skin [ 62 , 63 , 80 , 93 ], sheep and goatskin [ 54 , 55 , 68 , 81 ], pigskin [ 82 , 94 ], and cattle skin [ 59 , 95 ].…”