Original article Encapsulation of protease from Aspergillus oryzae and lipase from Thermomyces lanuginoseus using alginate and different copolymer types Truong Thi Mong Thu, Wunwisa Krasaekoopt * Department of Food Biotechnology, Faculty of Biotechnology, Assumption University, Bangkok 10240, Thailand article info Article history: Received 15 June 2015 Accepted 28 January 2016 Available online 25 June 2016 Keywords: Copolymer Encapsulation Protease Lipase Extrusion abstract Although the application of enzymes in food as a food processing aid and enzyme supplement is of interest and widely used, the enzymes can be easily deactivated or lose their activity due to many causes such as pH and moisture as well as through the introduction of incompatible ingredients during food processing and storage. These problems can be solved by the encapsulation technique, especially in a gel matrix. The influences were studied of the alginate concentration, types of copolymer and their con- centrations on the bead size, encapsulation yield (EY), encapsulation efficiency (EE), leakage and the retention of enzyme activity during storage period of encapsulated protease from Aspergillus oryzae and lipase from Thermomyces lanuginosus beads. A solution of purified protease or lipase was encapsulated in calcium alginate-chitosan beads (CACB), calcium alginate-xanthan gum beads (CAXB) and calcium alginate-maltodextrin beads (CAMB) using the extrusion method. Increasing the alginate and copolymer concentrations in the solution increased the bead size, EY, EE and the retention of enzyme activity during the storage period and reduced leakage of both the encapsulated protease and lipase. In addition, different types of copolymer significantly (p  0.05) affected these properties of both encapsulated enzymes. Furthermore, protease encapsulated using 2.0% alginate and 0.2% chitosan provided the highest EY (81.7%) and EE (77.2%) with a bead size of 1.85 mm and 8.1% leakage. The retention of encapsulated protease activity and the shelf-life of encapsulated enzyme which was expressed as half-life, the time required for the enzyme activity to decrease by half (t half life ) were 75.8% and 27.2 wk, respectively after storage at 4  C for 10 wk. For lipase, encapsulation using 2.0% alginate and 0.4% xanthan gum provided the highest EY (42.5%) and EE (43.9%) and the bead size and leakage were 1.81 mm and 6.2%, respectively. The retention of encapsulated lipase activity and the t half life were 77.9% and 27.8 wk, respectively after storage at 4  C for 10 wk. CACB was a suitable complex polymer for encapsulating protease while CAXB was suitable for lipase. EY and EE values of CACB-protease were higher than those of CAXB-lipase. Therefore, the encapsulation method, gelling conditions and interactions between carriers and lipase should be further studied. Copyright © 2016, Kasetsart University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Introduction The global market for industrial enzymes was estimated at 3.3 billion dollars in 2010 and this market was expected to reach more than 4 billion dollars by 2015 (Gurung et al., 2013). Hydrolases (predominantly proteases and amylases followed by lipases) made up at least 75% of all such enzymes with 90% of them being pro- duced from microorganisms by fermentation (Li et al., 2012). Proteases are enzymes capable of hydrolyzing the peptide bonds between amino acids of proteins and occur in plants, animals and microbes (Rao et al., 1998). Among all microbes, Aspergillus and Bacillus are normally generally recognized as safe strains with Aspergillus oryzae being the predominant fungal source of enzyme (Ou and Zhu, 2012). The neutral protease II (NpII) from A. oryzae is a zinc-containing metalloprotease, which is essential for catalytic activity and possesses the highest casein hydrolyzing activity (Ou and Zhu, 2012). Proteases remain the dominant enzyme type due to their extensive use in the dairy and detergent industries (Ou and Zhu, 2012). Lipase from Thermomyces lanuginosus catalyzes not only * Corresponding author. E-mail address: wunwisaKrs@au.edu (W. Krasaekoopt). Contents lists available at ScienceDirect Agriculture and Natural Resources journal homepage: http://www.journals.elsevier.com/agriculture-and- natural-resources/ http://dx.doi.org/10.1016/j.anres.2016.06.002 2452-316X/Copyright © 2016, Kasetsart University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/). Agriculture and Natural Resources 50 (2016) 155e161 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Elsevier - Publisher Connector