Abstract: In order to prepare aleuritic acid, lac resin was saponified under microwave assistance, followed by salting out and crystallization. The effects of three major process conditions including microwave power, NaOH concentration and microwave treatment time on aleuritic acid yield were explored by one-factor-at-a-time experiments. Further, the three conditions were optimized by response surface methodology. The optimal saponification conditions were microwave treatment power of 200 W, NaOH concentration of 25.8% and microwave treatment time of 31 min. Under the optimal saponification conditions, the highest yield of aleuritic acid was achieved to be 21.90%. The aleuritic acid obtained was characterized by infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscope (SEM) as even crystals with high purity. In summary, microwave-assisted saponification can provide a simple, time-saving and high-yield method for  the preparation of aleuritic acid.

Key words: microwave, saponification, aleuritic acid, response surface methodology