Aminopeptidase from Streptomyces gedanensis as a useful tool for protein hydrolysate preparations with improved functional properties.

UNLABELLED: The aim of the present study was to evaluate the efficiency of amino peptidase (AP) from Streptomyces gedanensis to produce protein hydrolysates (PHs) with better antioxidant, nutritional, and functional properties and to compare it with the PHs produced by commercial protease. Three proteins, soy, casein, and wheat protein were employed to produce their hydrolysates by applying 2% (w/w) AP at optimal conditions of pH 8.5 and temperature 55 °C. The results disclosed that the degree of hydrolysis ranges from 15.93 to 20.68% after 6 h showed better antioxidant activity and functional properties such as solubility, foaming properties, and water holding capacity than the commercial protease treated hydrolysates. AP treated PHs were enriched in Glu followed by Leu, Tyr, Lys, Phe, Asp, Met, His, Ile, Ala, and Val. Therefore, S. gedanensis AP would be an attractive microbial AP with high potential for the preparation of PHs which could offer industrial applications especially in the realm of producing food formulations as food additives in medicine and sport.

PRACTICAL APPLICATION: AP from S. gedanensis was found to be the most effective enzyme to produce PHs with good antioxidant, nutritional, and functional properties. The antioxidant and essential amino acids of AP treated PHs unveiled that this amino peptidase could give credence to eliminate the bitter taste by hydrolysis of peptides and could offer interesting possibilities for industrial applications, including debittering of protein hydrolysates. The findings could be useful in the food industry especially in the realm of producing food formulations requiring high protein supplements.