Speaker Biography

Leidy M. Sierra

Universidad de Antioquia Colombia

Title: Comparison between two enzymes in the hydrolysis of red tilapia scales (Oreochromis sp.)

Leidy M. Sierra
Biography:

Leidy Maritza Sierra Lopera received the Bs. Eng in Biological Engineering in 2007, the MSc degree in Science and Food Technology 2012, all of them from the Universidad Nacional de Colombia-Medellin Campus. Since 2009 she has been Part Time Professor in Universidad Nacional de Colombia-Medellin and she is a Ph.D student in Universidad de Antioquia. Her research interests include: food processing and food biotechnology.

Abstract:

Statement of the Problem: The red tilapia scales (Oreochromis sp.) is an important waste of the processing of this fish and its contained of protein is near of 29%, which can be used to obtain peptides with biological activity. For its extraction it is possible to use enzymatic hydrolysis with different proteases such as alcalase and flavourzyme. The objective of this work is to compare the enzymes alcalase and flavourzyme in the peptides extraction from red tilapia scales (Oreochromis sp.) with antioxidant and iron chelating potential. Methodology & Theoretical Orientation: The red tilapia scales (Oreochromis sp.) were washed with hypochlorite 0.2 mg/L and then stored at -20 ° C until processing, later they were dried and mixed. An experimental design of response surface (DOE) was carried out, central composed with the factors temperature and pH to search the optimal conditions for each enzyme. The response variables were: protein (g / L) and degree hydrolysis GH (%). The hydrolysis time was 3 hours with constant agitation in a 500 mL reactor and substrate concentration was 8 g/L of protein. Findings: Significant models were obtained for the variables evaluated and it was observed that the optimal conditions of pH/temperature were 8.5/58.5°C and 7.56/53.5 for alcalase and flavourzyme respectively. For variable GH was obtained that the hydrolysis process had 17% for alcalase and 6% for flavourzyme. Besides the percentages of protein extraction were 84% for alcalase meanwhile 46% for flavourzyme. On the optimal conditions were evaluated the bioactivities, alcalase is more productive than flavourzyme due to it´s possible obtain 107 (µM ET/gr*mL alcalase) in comparation with 54 (µM ET/gr*mL flavourzyme), in iron quelating potential is similar for two enzymes. Conclusion & Significance: hydrolysis performed with alcalase is more convenient to obtain hydrolysates with bioactivity from scale fish of red tilapia (Oreochromis sp.).