High-throughput approach for the screening of mineral-chelating activities of enzymatic milk protein hydrolysates

Taking advantage of high-throughput microscale workflow, that optimizes substrate and enzyme use and mostly experimental time, this study aimed to develop novel protein hydrolysates with mineral-chelating properties from a widely studied protein source and well-known food-grade enzymes. Ingredients from the dairy industry (milk protein isolate (MPI), micellar casein isolate (MCI) and whey protein isolate (WPI)) have been treated with five commercial food-grade enzymatic blends; Alcalase 2.4 L FG, Flavorpro 766 MDP, Flavourzyme 1000 L, Formea T 1200 BG and Promod 523 MDP; using a high reproducibility parallelized microbioreactor system. Various combinations of these blends, used simultaneously or sequentially, resulted in over one hundred unique hydrolysates. Their abilities to bind calcium, magnesium, ferrous iron, zinc and their degree of hydrolysis (DH) were screened employing a series of five automated spectrophotometric microplate assays. Multivariate analysis indicated that MPI and MCI hydrolysates exhibited comparable mineral-chelating properties, whereas WPI hydrolysates demonstrated overall inferior mineral binding properties. The results also underscored the role of specific enzymatic treatments on each substrate in enhancing mineral-chelating efficiency of the produced hydrolysates. This study demonstrates the potential of high-throughput workflow to accelerate the development of functional ingredients tailored for tackling mineral deficiencies.