Table 4. Key volatile compounds retained from electronic-nose profiling (discrimination power > 0.900) with column assignment (MXT-5 or MXT-1701) and qualitative contribution to group separation in PCA

Column	RT (min)	Discrimination power	Compound	Odor description1)
MXT-5	19.54	0.986	butanal	chocolate, cocoa, green, musty, pungent
	24.01	0.990	2-methyl-1-propanol	alcoholic, bitter, chemical, fusel, glue, leek, licorice
	34.22	0.997	propanoic acid	acidic, soy, vinegar
	35.35	0.987	butyl acetate	banana, bitter, fruity, green, pear, pineapple
	37.81	0.987	propylenglycol	alcoholic, caramelized, odorless
	50.29	0.997	isoamyl acetate	apple, banana, ester, fresh, fruity, pear
MXT-1701	26.30	0.992	ethyl acetate	acidic, butter, caramelized, fruity, green, orange, pineapple
	27.26	0.994	butan-2-one	acetone, butter, cheese, chemical, chocolate, fruity
	43.71	0.986	furfural	almond, baked, benzaldehyde, bread, fragrant, sweet, sweet, woody
	52.10	0.995	ethyl 2-methylbutyrate	apple, blackberry, cognac, fruity, green, phenolic

Odor descriptors were adopted from the built-in reference library of the electronic nose system (Astree II, Alpha MOS, Toulouse, France).