Abstract:

This study was aimed to optimize the extraction process for polyphenoloxidase (PPO) from honeysuckle (Lonicera
japonica Thunb.) flowers using response surface methodology. The results showed that four operating parameters including
buffer pH, material-to-liquid ratio, extraction time and polyvinylpyrrolidone(PVP) concentration had notable effects on the
extraction of PPO from honeysuckle flowers and their effects could be ranked in decreasing order of importance as follows:
buffer pH ＞ material-to-liquid ratio ＞ extraction time ＞ PVP concentration. The optimal extraction parameters were
determined as pH 8.03 and 1:6.29 (m/V) of material-to-liquid, 1 g/100 mL PVP added to the extraction solvent and extraction
for 1.71 h , resulting in a PPO specific activity of 667.564 U/mg. The established regression model describing PPO extraction
from honeysuckle flowers as a function of the four extraction parameters was highly significant (R2＝0.9425). The predicted
and experimental results were found to be in good agreement. Thus, the model can be applicable for the prediction of PPO
extraction from honeysuckle flowers.

Key words: honeysuckle, polyphenoloxidase (PPO), extraction, response surface optimization