Fig. 5

DL analysis of Zingiber officinale Roscoe samples. a DL decay curves of Zingiber officinale Roscoe samples of different ages. BG = background. b DL properties of the three different Zingiber officinale Roscoe samples. I0 is the initial intensity of the DL curve, Beta is an index factor associated with the rate of DL decay, and Tau and T represent the DL characteristics and decay time, respectively. *p < 0.05. c PCA score plot of the DL properties obtained from Zingiber officinale Roscoe samples. d PCA biplot showing how each parameter influences the similarity of DL decay curves