Vol. 11(30), pp. 2678-2688, 28 July, 2016 DOI: 10.5897/AJAR2016.11183 Article Number: B21F6C059730 ISSN 1991-637X Copyright ©2016 Author(s) retain the copyright of this article http://www.academicjournals.org/AJAR African Journal of Agricultural Research Full Length Research Paper Gelatin extraction from Kumakuma (Brachyplathystoma filamentosum) skin using the liming method Elen Vanessa Costa da Silva 1 *, Rosinelson da Silva Pena 2 and Lúcia de Fátima Henriques Lourenço 3 1 Food Technology Department, Estadual University of Pará, UEPA, Belém, PA, Brazil. 2 Faculty of Food Engineering, Technology Institute, Federal University of Pará (UFPA), Postal code: 66075-110, Belém, PA, Brazil. 3 Faculty of Food Engineering, Federal University of Pará (UFPA) – Rua Augusto Côrrea, 01, P. O. Box 479, Postal Code: 66075-110, Belém, PA, Brazil. Received 4 May, 2016; Accepted 14 July, 2016 Gelatin extraction process from Kumakuma (Brachyplathystoma filamentosum) skin was optimized using a calcium hydroxide solution. The gelatin obtained was characterized through scanning electron microscopy and analyses of yield, gel strength, color, viscosity, amino acid profile, melting point, foaming capacity, and emulsifying capacity. The optimized conditions were defined over ten days of pre-treatment at 50°C. This condition resulted in desirability of 0.965 and yield and gel strength values of 20.24% and 221 g, respectively. Glycine was the main amino acid both in the fish skin (11.68%) and in the gelatin obtained (23.39%). Gelatin had extendable and consistent gel characteristics and its microstructure showed even threads with small gaps throughout, which is favorable for the food industry. Key words: Residue, fish, pre-treatment, gelatin, gel strength. INTRODUCTION Gelatin is a valuable protein derived from animal by- products obtained through partial hydrolysis of collagen originated from cartilages, bones, tendons and skins of cold-water (cod, king weakfish, salmon, among others), and warm-water fish (tuna, catfish, tilapia, among others) (Sakr, 1997). However, no study has been carried out with the Amazon species Kumakuma (Brachyplathystoma filamentosum), a large-size fish that can reach over 1.5 m in the overall length and weigh 100 kg, which is widely used in the filleting industry (Gonçalves et al., 2003). The procedures used to extract collagen from fish normally involve chemical pre-treatment of the raw material and mild temperature during the process (Karim and Bhat, 2009). Depending on the method employed in the pre-treatment, two types of gelatin with different characteristics can be produced. Type-A gelatin (isoelectric point at pH 6 to 9) is produced by acid treatment of the collagen, while type-B gelatin (isoelectric *Corresponding author. E-mail: elen.vanessa@bol.com.br. Tel: +5591981140062. Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License