Extraction of collagen from raw trimming wastes of tannery: a waste to wealth approach

Discharge of huge quantities of raw skin/hide trimming wastes by leather industries has raised serious
concerns on account of their environmental impacts. It is imperative to develop a simple method for the
utilization of this waste to provide a practically feasible and economically viable solution. The trimmings
contain high amount of fibrous protein, which are actually a valuable bioresource. The study presents the
extraction of collagen, a product of high value, from raw trimmings. Experiments were carried out using
propionic acid and acetic acid for the solubilisation of collagen from skin matrix. Of these acid extraction
methods, propionic acid method showed higher yield of collagen (~93%) compared to the acetic acid
extraction (~85%). The extracted collagen was further characterised by physicochemical techniques such
as SDS-PAGE, circular dichroism and infrared spectroscopy. It was concluded that the collagen extracted
from trimming waste using both acids were of type I and also found to have similar physicochemical
properties. Therefore, the raw skin/hides trimming waste can be a cheap source of collagen, which has
many high end applications like tissue engineering, biomaterials, cosmetics and pharmaceutical industry.