Aroma Changes in Fresh Bell Peppers (Capsicum annuum) after Hot-air Drying

The aroma of fresh and hot-air dried bell peppers (Capsicum annuum) was evaluated by sensory and instrumental methods. Hot-air drying decreased levels of the odor compounds (Z)-3-hexenal, 2-heptanone, (Z)-2-hexenal, (E)-2-hexenal, hexanol, (Z)-3-hexanol, (E)-2-hexenol, and linalool, which have green, vegetable-like, fruity, and floral notes, while intensity scores of corresponding sensory aroma attributes also decreased. The aroma of rehydrated dried samples was mainly characterized as savory, rancid/sweaty, sweet/sickly, hay-like, cacao, caramel, and nutty. Drying increased the levels of 2-methylpropanal, 2-and 3-methylbutanal, which have cacao, spicy, and rancid/sweaty odor notes; these volatiles may be correlated with the corresponding aroma attributes in the dried fruits. Principal component analysis demonstrated relationships between instrumental and sensory data for fresh samples, whereas they were more complex for dried fruits.