TY - JOUR
T1 - Towards the development of a membrane reactor for enzymatic inulin hydrolysis
AU - Díaz, Elena González
AU - Catana, Rui
AU - Ferreira, Bruno S.
AU - Luque, Susana
AU - Fernandes, Pedro
AU - Cabral, Joaquim M.S.
PY - 2006/3/31
Y1 - 2006/3/31
N2 - Ultra high fructose syrup is of increasing importance, because of its sweetening properties. Fructose is often obtained by glucose isomerization. However, this process has a relatively low conversion (around 45%), and it uses a complex purification scheme. An alternative process involves the hydrolysis of natural products, such as inulin, a polymer which contains between 5 and 65 molecules of fructose. The use of enzymes in such hydrolysis reactions would add the benefit of mild reaction conditions and a better product profile. In this work, the enzymatic hydrolysis of inulin has been studied in a membrane reactor (EMR). A first set of experiments aimed to find the optimum operating conditions, in terms of pH (a value of 4.5 was obtained as optimum), substrate concentration (a maximum of 100 g/L is recommended, because of the ease of inulin precipitation), and substrate/enzyme ratio. All experiments were conducted at 50°C. Then, enzymes were immobilized in order to be able to reuse them, which would result in a more economically feasible process. As immobilization supports both hollow fibre membranes and particulates have been used and compared, and methods of improving the amount and/or the stability of the immobilized enzymes have also been proposed and tested. The results show that the EMR is capable to retaining more than 50% of the initial activity that the enzyme has in solution over at least five repeated reaction cycles. This work can provide a preliminary basis for the production of fructose syrups with a commercial inulinase preparation immobilized onto a membrane.
AB - Ultra high fructose syrup is of increasing importance, because of its sweetening properties. Fructose is often obtained by glucose isomerization. However, this process has a relatively low conversion (around 45%), and it uses a complex purification scheme. An alternative process involves the hydrolysis of natural products, such as inulin, a polymer which contains between 5 and 65 molecules of fructose. The use of enzymes in such hydrolysis reactions would add the benefit of mild reaction conditions and a better product profile. In this work, the enzymatic hydrolysis of inulin has been studied in a membrane reactor (EMR). A first set of experiments aimed to find the optimum operating conditions, in terms of pH (a value of 4.5 was obtained as optimum), substrate concentration (a maximum of 100 g/L is recommended, because of the ease of inulin precipitation), and substrate/enzyme ratio. All experiments were conducted at 50°C. Then, enzymes were immobilized in order to be able to reuse them, which would result in a more economically feasible process. As immobilization supports both hollow fibre membranes and particulates have been used and compared, and methods of improving the amount and/or the stability of the immobilized enzymes have also been proposed and tested. The results show that the EMR is capable to retaining more than 50% of the initial activity that the enzyme has in solution over at least five repeated reaction cycles. This work can provide a preliminary basis for the production of fructose syrups with a commercial inulinase preparation immobilized onto a membrane.
KW - Amberlite
KW - Fructose syrup
KW - Inulin hydrolysis
KW - Inulinase
KW - Membrane bioreactor
UR - http://www.scopus.com/inward/record.url?scp=32444445993&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2005.12.005
DO - 10.1016/j.memsci.2005.12.005
M3 - Article
AN - SCOPUS:32444445993
SN - 0376-7388
VL - 273
SP - 152
EP - 158
JO - Journal of Membrane Science
JF - Journal of Membrane Science
IS - 1-2
ER -