Preparation Of Konjac Glucomanno-oligosaccharides With β-mannase In A Continuous Enzyme Membrane Reactor

Enzyme membrane reactor (EMR) is a recently developed membrane separation technology.which has the advandages of realizing continuous reaction, improving reaction efficiency and reducing production cost. More of this (EMR) technology has been used in food industries, biochemical engineering, agriculture, environmental protection and others areas. In this paper, the preparation of konjac glucomanno-oligosaccharides by EMR was studied on the following aspects.The establishment of platform that plate-type enzyme membrane reactor was for incompatible solid-liquid reaction was studied. The choice and nature of polyether sulphone (PES)flat ultrafiltration membrane was also studied. During the process of selecting membrane in theory, absolet removal rating of reaction products should be 0, and absolet removal rating of enzyme should be 100% completely to ensure enzyme to stay at reaction system. The results showed that absolet removal rating of molecular weight cut-off (MWCO) 5KD PES flat ultrafiltration membrane to neutralβ-mannanase and konjac flour were very good.Konjac flour was used for the substrate, glucomanno-oligosaccharides were prepared by EMR with neutralβ-mannanase. The total content of TRS and products between enzyme membrane reactor and intermittent reaction were compared. In the whole reaction process, The total content of TRS in enzyme membrane reactor was always more than that one in intermittent reaction. It was found to be 10% higher than that of intermittent reaction in 135 min. The products were detected by fluorophore-assisted carbohydrate electrophoresis (FACE), penetration end products from enzyme membrane reactor contained 9 different components. The component types of intercept end products from enzyme membrane reactor and intermittent reaction products were basically the same, both were found to contain 14 different components. Detection by HPLC showed that in penetration end products from enzyme membrane reactor, the content of trisaccharide is higher, but the content of relatively high degree of polymerization sugar was higher in intermittent reaction products. UPLC- MS/MS detection showed that penetration end products from enzyme membrane reactor and intermittent reaction products both contained glucomanno-oligosaccharides of polymeric degree 2~9.The conditions of enzyme membrane reactor were optimized through the single-factor experiments. The optimal parameters were determined by investigating the effects of reaction enzyme-substrate ratio (E/S), reaction temperature, pH, reaction time on TRS. The optimal reaction conditions of enzyme membrane reactor were as follows: E/S 0.2, temperature 55.0℃, pH 7.0 and time 135min.