PROCESS FOR THE PURIFICATION OF ASTAXANTHIN

摘要

The present invention is directed to a process for the manufacture of synthetic food-grade astaxanthin with a content of dichloromethane ≤ 250 ppm comprising the following steps: a) Providing synthetic astaxanthin crystals containing dichloromethane in a reactor; and b) Adding methanol to the synthetic astaxanthin crystals in an amount to obtain a suspension of synthetic astaxanthin in methanol, whereby the amount of synthetic astaxanthin in said suspension is in the range of from 5 to 70 weight-%, based on the total weight of the suspension, and closing the reactor; and c) bringing the suspension obtained in step b) to a temperature in the range of from 80 to 140°C; and d) Maintaining the suspension at the temperature as reached in step c); and e) Bringing the methanolic synthetic astaxanthin suspension to atmospheric pressure by releasing overpressure; and f) Cooling the synthetic astaxanthin suspension to a temperature in the range of 10 to 35°C; and g) Filtering off the synthetic astaxanthin crystals and drying them; whereby during the process the total amount of synthetic astaxanthin is not completely solved in the methanol at the same time, and whereby a synthetic food-grade astaxanthin with a content of dichloromethane < 250 ppm is obtained. Instead of synthetic astaxanthin crystals also a solution of synthetic astaxanthin in dichloromethane can be used as starting material.