Assessing the effect of Maillard reaction with dextran on the techno-functional properties of collagen-based peptides obtained from bovine hides

Abstract

The recovery of food processing co-products, in the meat sector, has become a hot topic. Based on previous studies, the enzymatic hydrolysis of bovine hides was proposed as a suitable and efficient recovery methodology to produce protein hydrolysates to be used in the food industry. It was found, however, that maximizing recovery yield lead to hydrolysates presenting very poor functional properties. Maillard reaction has been shown to modify the techno-functional properties of proteins without adding chemical agents. The glycation reaction occurred successfully as proved from the analysis of the free amino groups and the size exclusion chromatography (SEC). However, the glycated hydrolysates did not show an improvement in any of the techno-functional properties here assayed: foaming, gelling and emulsifying capacity. This lack of improvement was attributed to the low molecular weight of the peptides (less than 6.5 kDa in average, being the 60% of them lower than 3 kDa) required for recovering proteins from hides in high yields (>85%). When compared to non-hydrolysed collagen, the number of free amino groups per molecule in the hydrolysate is much lower, meaning that interactions between protein-protein and protein-matrix interactions are less evident.