Are green food dyes made of "silkworm poop"? No, that's not true: Green food coloring is made mainly from the alfalfa plant.
The claim appeared on TikTok (archived here) on June 9, 2023. In the video, a woman in a lab coat explains that the dyes used in food such as matcha desserts and gum might be "silkworm poop."
In the video, she says (translated from Japanese by Lead Stories staff):
Silkworm poop is dried, and in the process copper chlorophyllin is extracted, creating a dark green dye. When you buy matcha-flavored sweets, please check if there's copper chlorophyllin in it or not.
This is what the post looked like on TikTok at the time of writing:
(Source: TikTok screenshot taken on Fri Jun 16 03:42:48 2023 UTC)
Chlorophyll as a food dye is extracted from alfalfa or lucerne, which is a wild edible plant. While studies do exist that show the extraction of silkworm excrement can be used in the saponification process to obtain the dye, most commercially dyed sweets use the E 141 variant, which is extracted from plants and not from any form of fecal matter.
