Isolation and Characterisation of collagen from the skin of brownbanded bamboo shark (Chiloscyllium punctatum) Phanat Kittiphattanabawon a , Soottawat Benjakul a, * , Wonnop Visessanguan b , Hideki Kishimura c , Fereidoon Shahidi d a Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand b National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Rd., Klong1, Klong Luang, Pathumthani 12120, Thailand c Laboratory of Marine Products and Food Science, Research Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan d Department of Biochemistry, Memorial University of Newfoundland, St. John’s, NL, Canada, A1B 3X9 article info Article history: Received 26 June 2009 Received in revised form 3 September 2009 Accepted 9 September 2009 Keywords: Collagen Shark Skin ASC PSC Brownbanded bamboo shark Chiloscyllium punctatum Zeta potential abstract Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of brownbanded bamboo shark (Chiloscyllium punctatum) were isolated and characterised. The yield of ASC and PSC were 9.38% and 8.86% (wet weight basis), respectively. Based on protein patterns and TOYOPEARL Ò CM-650M col- umn chromatography, both collagens contained a- and b-chains as their major components. These were characterised as type I collagen with the cross-link of a2-chain. As digested by V8-protease and lysyl endopeptidase, peptide maps of both ASC and PSC were similar, but differed from that of type I collagen from calf skin. Fourier transform infrared (FTIR) spectra of both collagens were similar and pepsin hydro- lysis had no effect on triple-helical structure of collagen. Transition temperature (T max ) of ASC and PSC were 34.45 and 34.52 °C, respectively, as determined by differential scanning colorimetry (DSC). From zeta potential study, the isoelectric points of ASC and PSC were estimated to be 6.21 and 6.56, respec- tively. Therefore, the skin of brownbanded bamboo shark could serve as an alternative source of collagen for different applications. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Shark has been used as food for human consumption and can be further processed into many products. Different parts of sharks can be utilised such as shark meat (fillets and fish ball products), shark fin (dried shark fin), shark liver (shark liver oil contains a large amount of squalene, vitamins A and long-chain omega-3 polyun- saturated fatty acids, shark skin (sun dried products, leather), shark cartilage (shark cartilage powder and shark cartilage chondroitin for food and drug use) (Musick, 2005). Due to their thickness, shark skin can be used as an excellent source of collagen with the unique characteristics. Collagen is the major fraction of connective tissue and has been used in food, pharmaceutical and photographic industries (Regenstein & Zhou, 2007). Commonly, the main sources for colla- gen production are pig skin, cattle skin and bone. The outbreak of bovine spongiform encephalopathy (BSE) has resulted in justified anxiety amongst users of cattle collagen. Additionally, the colla- gen obtained from pig skin and bones cannot be used freely due to the religious constraint (Kittiphattanabawon, Benjakul, Visessanguan, Nagai, & Tanaka, 2005). As a consequence, much attention has been paid to alternative sources of collagen, espe- cially from fish skin and fish bone from the seafood processing industries. So far, skin collagen from several fish species have been isolated and characterised such as bigeye snapper skin (Jongjareonrak, Benjakul, Visessanguan, & Tanaka, 2005), Nile perch skin (Muyonga, Cole, & Duodu, 2004), Baltic cod skin (Sado- wska, Kolodziejska, & Niecikowska, 2003) and deep-sea redfish skin (Wang, An, Xin, Zhao, & Hu, 2007). Shark is another elasmo- branch, which has been used, for shark fin and fillet production. This processing leads to the generation of skin and cartilage, amongst others, which can be used as a potential raw material for collagen extraction. However, little information is available regarding the collagen from the skin of shark, especially those in the tropical regions. Therefore, the objective of this investigation was to isolate and characterise the collagen from the skin of brownbanded bamboo shark, a by-product from the shark pro- cessing plants. 0308-8146/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2009.09.037 * Corresponding author. Tel.: +66 7428 6334; fax: +66 7421 2889. E-mail address: soottawat.b@psu.ac.th (S. Benjakul). Food Chemistry 119 (2010) 1519–1526 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem