Collagen: From Waste to Gold

Abstract

Industrial processing of bovine hides into leather results in many unusable hide off-cuttings, shavings and trimmings. This waste raw material is under-utilised and presents a waste valorisation opportunity to derive a high-value product such as collagen. Collagen is a highly sought-after protein which consists of three polypeptide chains, comprising 30% of the mammalian body’s protein, being the main component of skin, connective tissue and cartilage. The demand for collagen is rising at approximately 20% annually and global collagen-based biomaterials market is predicted to reach US$5 billion by 2025. This chapter presents a waste valorisation opportunity to extract collagen from waste bovine hide off-cuttings. Further, it discusses collagen extraction method optimization and methods used to investigate physicochemical properties of collagen are reviewed.

In Vitro Antioxidant and Antiaging Activities of Collagen and Its Hydrolysate from Mackerel Scad Skin (Decapterus macarellus)

“…The low pepsin concentration (0.1%) with a longer soaking time (48 h) applied in the current study proved effective for extracting collagen from D. macarellus skin. Nevertheless, skin characteristics (i.e., thickness, initial protein content, lysine, and hydroxylysine content) may also influence the yield [ 19 ]. Collagen hydrolyzation with 1% collagenase II to produce hydrolyzed collagen (HC) was also quite effective, yielding 96% HC.…”

“…Pepsin has better reaction selectivity and is less damaging to collagen proteins. Thus, the extracted collagen will have better purity and maintain stable physical and chemical properties [ 19 ]. Collagen tends to be grayish-white and odorless.…”

A Comprehensive Review on Collagen Type I Development of Biomaterials for Tissue Engineering: From Biosynthesis to Bioscaffold

“…However, using this method, caution should be taken with the concentration of the salt as the key control factor. This is because salt such as NaCl may dissolve type I collagen in a neutral solution if less than 1 mol/L, but will precipitate type I collagen if more than 1 mol/L [ 75 ]. Furthermore, the removal of high concentrations of salt via dialysis may prolong the process, which typically takes three to seven days, thus reducing the extraction efficiency [ 76 ].…”

“…The enzymes break down the crosslinking in the collagen by cleaving amino telopeptides from the tropocollagen molecule, thus allowing it to be dissolved. This is most useful in mature tissue, whereby strong intermolecular bonds have formed as a result of ketoimine crosslinks [ 75 ]. Enzymatic extraction is frequently combined with acid to increase the yield and shorten the reaction time.…”

“…Notably, natural-based materials are not only more sustainable, but they also have higher biocompatibility, improved biodegradability, and in general, little to no toxicity [ 233 ]. Furthermore, in the context of the circular economy and sustainability, collagen sources such as bovine hide off-cuts [ 75 ], pig skin [ 82 ], chicken skin and eggshells [ 66 , 68 ], sheep legs [ 234 ], and fish scales [ 235 ] can be obtained from food waste. Moving forward, there is a significant need for protocols considering green chemistry such as using and fabricating products that are biodegradable and non-toxic to the environment.…”