OBJECTIVETo determine the major factors affecting the conversion efficiency of naringin-HP-beta-CD that was enzymed to prepare naringenin were determined and select the process condition with high conversion efficiency, stable and suitable for industrial production.

METHODThe dropping method was used to prepare naringin-HP-beta-CD, which was hydrolyzed by snailase to obtain naringenin. With the bioconversion rate as the index, the effects of pH value, temperature, reaction time, dosage of enzyme and concentration of naringin-HP-beta-CD on conversion rate of naringenin were detected for the purpose of optimizing the preparation condition. the conversion efficiency of naringin-HP-beta-CD was verified by scanning calorimetry, and the Hydrolysis product was identified by H-NMR, and 13C-NMR.

RESULTThe optimum enzymolysis of naringin-HP-beta-CD with snailase was 98.4% under the conditions of 37 degrees C, a pH 5.0 acetic acid- sodium acetate buffer solution for 12 hours. The substrate concentration was 30 g x L(-1) and the weight ratio of enzyme and substrate was 3: 5. Under the optimum enzymolysis condition, the conversion rate of naringin-HP-beta-CD was higher than naringin that was not entrapped with HP-beta-CD, with 272.25 reaction product relative molecules. The structure of naringenin was confirmed by the analysis of 1H-NMR and 13C-NMR.

CONCLUSIONNaringin which is entrapped with HP-beta-CD to prepare naringenin can significantly improve the conversion efficiency by shortening the reaction time, increasing the concentration of the substrate and reducing the amount of enzyme. Therefore, the process is stable and it was suitable for industrialization.