Enzymatic synthesis of sugar esters and their potential as surface-active stabilizers of coconut milk emulsions

• Published in: Food Hydrocolloids
• Main Authors: Neta, Nair do Amaral Sampaio, Santos, José Cleiton Sousa dos, Sancho, Soraya de Oliveira, Rodrigues, Sueli, Gonçalves, Luciana Rocha Barros, Rodrigues, L. R., Teixeira, J. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Ltd. 2012
• Subjects: Sugar esters; Chitosan; Acrylic resin; Yield; Emulsifier; Esterification; Science & Technology; Antarc*; Antarctica
• Online Access: https://hdl.handle.net/1822/16775; https://doi.org/10.1016/j.foodhyd.2011.10.009

Sugar esters are compounds with surfactant properties (biosurfactants), i.e., capable of reducing the surface tension and promote the emulsification of immiscible liquids. On the other hand, as with all emulsions, coconut milk is not physically stable and is prone to phase separation. Therefore, the aim of this work was to evaluate the synthesis of fructose, sucrose and lactose esters from the corresponding sugars using Candida antarctica type B lipase immobilized in two different supports, namely acrylic resin and chitosan, and evaluate its application in the stabilization of coconut milk emulsions. The enzyme immobilized on chitosan showed the highest yield of lactose ester production (84.1%). Additionally, the production of fructose ester was found to be higher for the enzyme immobilized on the acrylic resin support (74.3%) as compared with the one immobilized on chitosan (70.1%). The same trend was observed for the sucrose ester, although with lower percentage yields. Sugar esters were then added to samples of fresh coconut milk and characterized according to their surface tension, emulsification index and particle size distribution. Although the microscopic analysis showed similar results for all sugar esters, results indicated lactose ester as the best biosurfactant, with a surface tension of 38.0 N/m and an emulsification index of 54.1%, when used in a ratio of 1:10 (biosurfactant: coconut milk, v/v) for 48 hour experiments. The authors acknowledge the AlBan Programme (European Union Programme of High Level Scholarships for Latin America) for financial support of N. Lopes through the research grant E07D401544BR. Furthermore, the authors acknowledge the Chemical Engineering Department e Federal University of Ceara (Campus of Pici - Brazil) and Biotechnology Laboratory - Federal University of Ceara for enabling the use of their laboratory facilities.