Continuous Production of Galacto-Oligosaccharides by an Enzyme Membrane Reactor Utilizing Free Enzymes

Membranes

Teng Cao¹  Melinda Pázmándi¹  Zoltán Kovács¹  Ildikó Galambos² 

[1] Department of Food Engineering, Szent István University, Budapest 1118, Hungary;Soós Ernő Water Technology Research and Development Center, University of Pannonia, Nagykanizsa 8200, Hungary;

关键词: galacto-oligosaccharides (GOS);    ultrafiltration (UF);    enzyme membrane reactor (EMR);    operational stability;    lactose;    prebiotics;   

DOI  :  10.3390/membranes10090203

来源: DOAJ

【 摘 要 】

Galacto-oligosaccharides (GOS) are prebiotic compounds widely used for their health-promoting effects. Conventionally, GOS is produced by the enzymatic conversion of lactose in stirred tank reactors (STR). The high operational costs associated with enzyme inactivation and removal might be reduced by the application of enzyme membrane reactors (EMR). In this study, we aimed to assess the potential of continuous GOS production by EMR using soluble Biolacta N5, a Bacillus circulans-derived commercial enzyme preparation. The steady-state performance of the EMR equipped with an ultrafiltration module was investigated as function of residence time (1.1–2.8 h) and enzyme load (17–190 U·g⁻¹) under fixed operational settings of temperature (50 °C), pH (6.0), lactose feed concentration (300 g·kg⁻¹), and recirculation flow-rate (0.18 m³·h⁻¹). Results indicate that the yield of oligosaccharides with higher degree of polymerization (DP3-6) in STR (approx. 38% on total carbohydrate basis) exceeds that measured in EMR (ranging from 24% to 33%). However, a stable catalytic performance without a significant deterioration in product quality was observed when operating the EMR for an extended period of time (> 120 h). Approx. 1.4 kg of DP3-6 was produced per one gram of crude enzyme preparation over the long-term campaigns, indicating that EMR efficiently recovers enzyme activity.

【 授权许可】

Unknown