Figure 2.

Possible Formation Mechanism of Endogenous CDs in Food Items

Food ingredients undergo pyrolysis at the initial stage of heating, and small fluorescent molecules form. Short and long fluorescent polymer chains emerge in succession at the following heating stage. Fluorescent polymers further condense under heating conditions, leading to carbon core formation. The large carbon core breaks down to a small carbon core at the last stage, and carbon dots that emit strong fluorescence are formed.