New approach using alternative proteolytic enzymes to the conventional enzyme pronase for the isolation of bread melanoidins

Abstract

Bread melanoidins are melanoproteins classically extracted with the proteolytic enzyme pronase E (S. griserus). In this study, the structure and functionality of melanoidins extracted with the proteolytic enzymes papain (PE) and enzymes from B. subtillus (SP) and a mixture from B. subtillus and A. oryzae (MP) were evaluated. PE extracted melanoidins have the highest nitrogen (4.3 %) and protein (29 %) content. FTIR showed that PE had a higher protein content and pronase had higher in carbohydrates. The K420 and K345 values and antioxidant capacities of the PE extract were similar to pronase and higher than the other microbial enzymes. After in vitro digestion, the increased in the antioxidant capacity was most pronounced in the PE extract. No neurotoxicity was observed, as evidenced by no neuronal cell death or changes in neuronal ROS levels. These results indicate that the PE enzyme may be a good alternative to pronase for extraction of melanoidins.