Enzymatic hydrolysis as a means of recovering bovine hides: Laboratory and medium scale trials, characterization of hydrolysates and scale-up to semi-industrial scale

Abstract

A current hot topic in the field of environmental protection and development of valuable new products is represented by the recovery of food waste from the meat sector. The present study focused on the recovery of bovine hides by means of a sustainable method. Enzymatic hydrolysis was selected as a potential green methodology for use in the production of protein hydrolysates to be applied on an industrial scale. For this purpose, the enzymatic hydrolysis of bovine hides with Alcalase was investigated following a multiscale approach: lab-scale, medium-scale and semi-industrial pilot plant. Alcalase proved to be highly efficient due to its ability to degrade collagen, the main protein of hides. Under optimized conditions, the hydrolysis of hides at lab-and medium-scales resulted in approx. 85% protein solubilisation after 6 hours, with a consistent release of free amino acids and a degree of hydrolysis of 17-19%. How-ever, in the pilot plant, solubilisation decreased due to difficulties in mixing bovine hides in the reactor, which was compensated with a longer reaction time to achieve virtually total protein solubilisation (∼98%). The present data therefore demonstrate the applicability of the process at semi-industrial scale in protein recovery with a reduced amount of waste by-products.