1. Normal seaweed soup is green. When the seaweed is put into the pot when making soup, the original color fades and turns green due to the reaction of the pigment protein.

2. Nori is called nori. Its color is purple because it contains a special pigment protein called phycoerythrin. Phycoerythrin can be dissolved in water, and this This pigment protein is very unstable and easily decomposes especially when exposed to high heat.