Stabilization of Endophytic Fungus Cercospora kikuchii Lipase by Spray Drying in the Presence of Maltodextrin and β-Cyclodextrin

Abstract

In this study the effects of spray-drying conditions on the retention of enzyme activity of lipase produced by the endophytic fungus Cercospora kikuchii have been investigated. Drying runs were carried out in a bench-top spray dryer with a concurrent flow regime. The influence of the variables inlet temperature of drying gas, T_gi (86.4 to 153.6°C); mass flow rate of the enzymatic extract fed to the dryer, W_s (2.63 to 9.36 g/min); and concentration of the drying adjuvant added to the extract, ADJ (1.95 to 12.05%), on the spray-drying performance and on product quality was evaluated through experimental planning and regression analysis. The use of maltodextrin, as a stabilizing agent, slightly improved the retention of enzyme activity compared to β-cyclodextrin. Statistical optimization of the experimental results allowed the determination of the processing conditions that maximized the retention of the enzymatic activity (R_AE), namely, concentration of drying adjuvants of 12.05%, inlet temperature of the drying gas of 153.6°C, and flow rate of the enzymatic extract fed to the dryer of 9.36 g/min for the both drying adjuvants investigated.

Keywords:

• Cercospora kikuchii
• Enzyme stabilization
• Lipase
• Spray drying

ACKNOWLEDGMENTS

This study was supported by Fundação de Amparo a Pesquisa do Estado de São Paulo–FAPESP (Biota Process number: 04/07935–6). T.A. Costa-Silva received a fellowship from FAPESP (Process no. 08/52732–7).

Notes

ADJ = concentration of drying adjuvant; R_AE = retention of the enzymatic activity; R_EC = product recovery; T_gi = inlet gas temperature; T_go = outlet gas temperature; X_P = moisture content; EXC = type of drying adjuvants; W_s = feed flow rate.

*Significant at 0.01; **significant at 0.05; ***significant at 0.10.

L = linear effect; Q = quadratic curvature effect.