Optimization of Nitrogen Recovery of Whey Protein Hydrolysates by using Response Surface Methodology

Subject Areas : Microbiology

Sh. Piri Gheshlaghi ¹ (دانشجوی کارشناسی ارشد علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران)
A. R. Sadeghi Mahoonak ² (دانشیار دانشکده علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران)
M. Alami ³ (دانشیار دانشکده علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران)
M. Ghorbani ⁴ (دانشیار دانشکده علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران)

Received: 2016-08-25 Accepted : 2016-08-25 Published : 2016-09-22

Keywords: Alcalase Enzyme, Enzyme Hydrolysis, Nitrogen Recovery, RSM, Whey Protein,

Abstract :

Introduction: Nitrogen recovery is an important factor to evaluate the function of enzymes in protein hydrolysis and the efficiency of the hydrolysis process, which is regarded economically important. The optimization of nitrogen recovery can save time and cost therefore this research work has aimed on this aspect.  Materials and Methods: In the present study, Response Surface Methodology has been employed to optimize the conditions for preparing protein hydrolysate from whey protein using the enzyme alcalase. Temperature of 43-52°C and time of 65-175 minutes and enzyme/substrate ratio of 45-90 (AU/Kg protein) were employed to achieve the maximum nitrogen recovery and experiments were designed according to the central composite design. Results: The results indicated that optimal conditions to achieve the highest nitrogen recovery were at the temperature of 47.1°C and time of 173.2 minutes, with the enzyme/ substrate ratio of 87.98 (AU/Kg protein). Under these conditions, the degree of hydrolysis was 70.66%. The regression coefficient for the presented model (Quadratic type) was, 0.9747. The values obtained indicated the high accuracy of the model to predict the reaction conditions with regard to different variables. Conclusion: The advances in technology have made the application of protein hydrolysate from unavailable various sources useful and available. Therefore whey protein hydrolysates as a rich source of healthy peptides with various functional properties and other desirable characteristics might be employed in food manufacturing and formulations.