Abstract

One of the main challenges of the tannery industry is the management of the waste generated during the leather manufacturing process. This study aimed to recover the collagen from tanning industry waste to acquire knowledge about its conversion into high value-added ingredients with bio-functional properties. To this end, collagen was purified from rawhide waste from the leather industry, characterised by electrophoresis and compared with commercial collagen. Subsequently, it was subjected to an enzymatic treatment using plant proteases from Bromelia hieronymi under mild reaction conditions to produce hydrolysates, since the production of bioactive peptides by enzymatic hydrolysis is a sustainable way of taking advantage of protein by-products. The hydrolysates were characterised by matrix-assisted laser desorption/ionisation time-of-flight (MALDI TOF) mass spectrometry, showing peptides with molecular weights ranging from 1,000 to 6,000 Da. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis allowed identifying 31 peptides from the ɑ1 chain of type I collagen and another 13 from the ɑ2 chain of type I collagen. The probability that the peptides identified were bioactive was predicted with the Peptide Ranker software (‘in silico analysis’). This demonstrated that 70% of them had high bioactive potential. These results showed that the collagen recovered from the waste of the tannery industry and hydrolysed by proteases from Bromelia hieronymi becomes a suitable source to obtain a product with greater added value than the original material and with multiple potential industrial applications.