Figure 2. Scatter plots between optical density of safranin O and different univariate FT-IR PG parameters.

A) Integrated area of carbohydrate region (984–1140 cm⁻¹). B) Integrated area of carbohydrate region normalized with amide I (1584–1720 cm⁻¹). C) Intensity of ^2nd derivative peak located at 1374 cm⁻¹. D) Intensity of 2^nd derivative peak located at 1062 cm⁻¹. Statistical significance of p<0.001 is indicated by two asterisks (**).