Fig. 5. Heat map analysis of electronic nose sensor response values of apple samples treated with different treatments: (a) blank apple samples, apple samples treated with 0.2 ppm cypermethrin, 1 ppm chlorpyrifos, and mixed ratio (0.2 ppm cypermethrin : 1 ppm chlorpyrifos = 1 : 9); (b) blank apple samples and apple samples treated with 0, 0.2, 1, 2, 3, 4 ppm cypermethrin; (c) blank apple samples and apple samples were treated with chlorpyrifos with 0, 1, 2, 4 and 8 ppm.
