%0 Journal Article
%T Protease from Aspergillus oryzae: Biochemical Characterization and Application as a Potential Biocatalyst for Production of Protein Hydrolysates with Antioxidant Activities
%A Ruann Janser Soares de Castro
%A Helia Harumi Sato
%J Journal of Food Processing
%D 2014
%R 10.1155/2014/372352
%X This study reports the biochemical characterization of a protease from Aspergillus oryzae LBA 01 and the study of the antioxidant properties of protein hydrolysates produced with this protease. The biochemical characterization showed that the enzyme was most active over the pH range 5.0¨C5.5 and was stable from pH 4.5 to 5.5. The optimum temperature range for activity was 55¨C60¡ãC, and the enzyme was stable at temperatures below 45¡ãC. The activation energy () for azocasein hydrolysis and temperature quotient () were found to be 37.98£¿kJ£¿mol£¿1 and 1.64¨C1.53 at temperature range from 30 to 55¡ãC, respectively. The enzyme exhibited of 97.63£¿min and a value of 324.31 at the optimum temperature for activity (57.2¡ãC). Protease from A. oryzae LBA 01 was shown as a potentially useful biocatalyst for protein hydrolysis, increasing the antioxidant activities of soy protein isolate, bovine whey protein, and egg white protein from 2.0- to 10.0-fold. 1. Introduction Proteases are multifunctional enzymes and represent a fundamental group of enzymes due to diversity of their physiological roles and biotechnological applications [1]. These enzymes are extremely important in the pharmaceutical, medical, food, and biotechnology industries, accounting for nearly 60% of the whole enzyme market [2]. It has been estimated that microbial proteases represent approximately 40% of the total worldwide enzyme sales [3]. Fungi are a potential source of proteases due to their broad biochemical diversity, their susceptibility to genetic manipulation, high productivity, and being extracellular and are easily recoverable from the fermentation medium [1, 4]. Aspergillus oryzae (A. oryzae) is a filamentous fungus listed as a ¡°Generally Recognized as Safe (GRAS)¡± organism by the US Food and Drug Administration. It has a long history of use in the food industry in the production of traditional fermented foods, due to its high proteolytic activity and its use of sugar [5, 6]. According to Machida et al. [7] the molecular history of the organism shows that A. oryzae has the largest expansion of hydrolytic genes (135 proteinase genes). The biochemical characterization of enzymes is important to evaluate their biotechnological potential. The study of the protease properties, such as the influence of inhibitors or activators, the substrate specificity, the optimum catalytic pH conditions and the temperature, and stability profiles and kinetic parameters, can be used to predict the successful application of the enzyme to particular industries or processes. The application of proteases to the
%U http://www.hindawi.com/journals/jfp/2014/372352/