Abstract: Chlorophyll copper sodium salt as a non-toxic water soluble chlorophyll derivative has excellent stability and colorability and is widely used as a food additive. In the present study, the traditional preparation process for sodium copper chlorophyllin from silkworm excrement chlorophyll was modified to develop a semi-synthesis method based on alkaline cuprammonium replacement. Four reaction conditions such as ethanol concentration, pH, reaction temperature and copper amount were chosen for synthesis process optimization based on orthogonal array design using SAS statistical software. The optimal copper amount, ethanol concentration, reaction temperature and pH were 2.5 times higher than the theoretic value, 75%, 55 ℃, and 11.5, respectively. Under these conditions, the ethanol consumption for copper replacement was reduced by 10%, and the quality of the product obtained was in accordance with the national standard of food additives.

Key words: silkworm excrement, cuprammonium method, sodium copper chlorophyllin, process conditions, SAS statistical software