COMMUNICATION Tannase Immobilization by Chitin-Alginate Based Adsorption-Entrapment Technique and Its Exploitation in Fruit Juice Clarification Arijit Jana 1 & Suman Kumar Halder 1 & Kuntal Ghosh 1 & Tanmay Paul 1 & Csaba Vágvölgyi 2 & Keshab Chandra Mondal 1 & Pradeep Kumar Das Mohapatra 1 Received: 30 April 2015 /Accepted: 18 August 2015 # Springer Science+Business Media New York 2015 Abstract Present study aimed to immobilize the bacterial tannase on suitable carrier and its subsequent applicability in fruit juice clarification. Tannase from Bacillus subtilis PAB2 was immobilized on chitin-alginate bead by adsorption- entrapment technique. Maximum immobilization (82 %) with an activity yield of 67 % was achieved in presence of 1.5 % (w/v) sodium alginate, 1 M CaCl 2 and 1 % (w/v) flake chitin, incubation at 4 °C temperature, and adsorption period of 90 min. Thermal and pH stabilities of immobilized tannase increased in respect to free tannase. The storage stability and reusability of the immobilized tannase were also improved significantly, retaining 83 % activity after storing 90 days at 4 °C and it showed 79 % residual activity after 10 times re- peated use. Then, immobilized tannase was applied for clari- fication of jamun and cashew apple juice to investigate its debittering property. Enzymatic treatment removed 60 and 51 % tannin from jamun and cashew apple juice, respectively, after incubation at 40 °C for 120 min. Other qualitative indi- cator viz., total titratable acidity, color, and viscosity also re- duced, whereas, flavonoid (460.49 μg/ml; 994.44 μg/ml), glu- cose (6.95 mg/ml; 9.19 mg/ml), and antioxidant activity (69.28 %; 78.44 %) were significantly increased in clarified jamun and cashew apple juice, respectively. Keywords Immobilized tannase . Adsorption . Chitin-alginate bead . Clarification Introduction Human body requires various macro- and micronutrients to meet the need for their muscular activities and caloric require- ments (Benton 1972). Fruit or fruit by-products are very useful source to accomplish the dietetic demand of human body. More than 500 edible fruits grow in the tropical and sub- tropical regions, but only 15 % are commercially processed for juice production such as pineapple, mango, guava, banana, kiwi etc. (Ramadan and Moersel 2007). Tannin content in the fruit juices that related to the bitterness is the major obliging factor to the consumers. Moreover, tannin has an affinity to bind with macromolecules, therefore, rendering them indi- gestible. Till date, adsorption techniques have been widely reported for debittering of several fruit juices (Chien et al. 2001), but loss of acidity, sweetness, flavor, and nutrients as well as less efficiency in debittering makes it inferior. Gelation-mediated polyphenolics removal has been common- ly employed in juice preparation. By conventional gelatin method, all polyphenolic substances, which are responsible for antioxidant activity, are removed and as a result, the quality of the product is reduced. In this context, tannase-mediated juice debittering has showed great potential in industrial applications both in terms of quality improvement and cost saving (Rout and Banerjee 2006; Srivastava and Kar 2010). Tannase (EC, 3.1.1.20) is an inducible, intracellular/extracellular microbial enzyme that catalyzes the hydrolysis of ester and depside linkages of tan- nin, which is the sole responder of bitterness, turbidity, and undesirable cloudiness in fruit juices and wine (Jana et al. 2014). In spite of its high catalytic efficiency, utilization of free tannase makes impractical due to some problems like high cost of purified tannase, low stability, product recovery which collectively makes the production costly and tough (Sheldon 2007). In order to overcome the shortcomings, * Pradeep Kumar Das Mohapatra pkdmvu@gmail.com 1 Department of Microbiology, Vidyasagar University, Midnapore, West Bengal 721102, India 2 Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary Food Bioprocess Technol DOI 10.1007/s11947-015-1586-9