A novel anti-counterfeiting method: Application and decomposition of RB for broad bean seeds (Vicia faba L.)

• Fluorescent dyes were successfully used as a new anti-counterfeiting method for broad been seeds.
• The broad bean seedling establishment was improved to some extent when rhodamine B was marked on seeds by seed coating.
• Anti-counterfeiting fluorescent label could be observed in cotyledon, the stem and the roots.
• The fluorescent compound of rhodamine B could be absorbed by field soil effectively, so the rhodamine B could not pollute soil and be used as an anti-counterfeiting marker for different crop seeds.

Combining with seed coating method, rhodamine B (RB), a kind of fluorescent compounds had been used in seed labeling as an anti-counterfeiting technology. Effects of broad bean seed coating with RB on physiological parameters and fluorescence performance in broad bean seedlings were performed. The prolonged fluorescence in vascular bundles of seedlings treated with RB could be used as a marker of seed anti-counterfeiting. The experiment showed that RB had no negative effect on seed germination, seedling growth, seedling protective enzyme activities, and the contents of malondialdehyde (MDA) and chlorophyll, after coating seeds with ratio 1 kg RB to 10–30 kg seeds. In addition, the RB adsorption by soil was accorded with the isothermal adsorption equations of Langmuir, which exhibited the linear correlation as 0.9959, the maximum adsorption as 1.716 mg/g, and the adsorption equilibrium constant as 0.042 L/mg. The soil adsorption of RB could be effectively degraded by UV/Fenton. Present research suggested that coating broad bean seeds with appropriate concentration RB were safe to seed germination and this technology was suitable for anti-counterfeiting application.