Abstract: Activated bentonite, activated carbon and attapulgite clay were chosen to match each other into a certain proportion to remove pigments in the silkworm pupa oil. Taking the comprehensive indicator of decolorization effects as a quality index, it was found that decolorization effects of the attapulgite clay were the best. The optimum decolorization conditions studied were as follows: clay dosage 8 g attapulgite clay activated at 300 ℃ in 1 h per 100 mL oil, decolorization temperature 50 ℃, decolorization time 40 min, and stirring speed 120 r/min. The Lovibond red value of silkworm pupa oil decreased from 8.5±0.1 to 3.1±0.0 and the yellow value decreased from 70.0±0.0 to 22.0±0.0, the decolorization effect comprehensive indicator is 3.979±0.008, and oil loss is 15.5%±0.1%.

Key words: activated bentonite, activated carbon, attapulgite clay, decolorization, silkworm pupa oil