Aspergillus sojae isolated from a traditional Korean fermented soybean product exhibited strong naringinase activity. The naringinase enzyme was purified and had a molecular weight of 70. kDa. The α- l-rhamnosidase activity of this enzyme was optimal at pH 6.0 and stable in the pH range of 5.5-8.0. The purified enzyme also had β- d-glucosidase activity, but the activity was relatively weak compared to the activity of the naringinase from Penicillium decumbens. The enzymatic bioconversion by A. sojae naringinase of naringin to prunin was efficiently performed with a 91% yield and a negligible amount of naringenin. The bioconversion was achieved by repetitive batch reactions with enzyme recycling. Prunin exhibited a markedly enhanced solubility compared to naringenin and naringin while maintaining the in vitro inhibition of HMG-CoA reductase. The results reported in this paper show that the naringinase produced by A. sojae will be useful in enhancing the potential bioavailability of naringin by efficiently converting it to prunin as a food component in citrus.
Bibliographical noteFunding Information:
This study was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea Government (MEST) ( 2009-0077358 ), and partly by a technology development programme for agriculture and forestry, Ministry of Agriculture and Forestry (No. 203022-3 ), and a research project from Yonsei University (2009-1-0149).
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Food Science