Fig. 1. Processing method flowchart

Fig. 2. Fluorescence spectrum before and after scatter removal and SG smoothing
(a): Before processing; (b): After processing

Fig. 3. Emission spectrum at the fluorescence excitation wavelengths before and after preliminary filtering
(a): Before preliminary filtering; (b): After preliminary filtering

Fig. 4. Emission spectrum feature bands of the two batches of banana
(a): The first batch; (b): The second batch

Fig. 5. Cluster analysis results of the two batches of banana
(a): The first batch; (b): The second batch

Fig. 6. PCA results of the two batches of banana
(a): The first batch; (b): The second batch