Revealing the key aroma codes and (furan) fatty acids in fresh red goji berries and the impacts of the hot-air drying process

The key aroma components and (furan) fatty acids in fresh red goji berries were determined and their variations after hot-air drying were investigated to understand the impacts of drying. 22 of the 46 detected aroma components were found to be the key aroma components in fresh red goji berries, including (E)-β-damascenone, 1-octen-3-one, and trans-4,5-epoxy-(E)-2-decenal, which elicited the cooked apple-like, mushroom-like, and metallic odor impressions. Linoleic acid, oleic acid, and palmitic acid were the predominant fatty acids. Furan fatty acid (FuFA) in fresh red goji berries was measured for the first time and 11-(3,4-dimethyl-5-pentylfuran-2-yl)-undecanoic acid (11D5) was the only FuFA. The subsequent analysis of hot-air-dried red goji berries at 50 °C caused the increment in the contents of fatty acids. A remarkable decrease was found in lipid-derived aroma components and FuFA, especially aldehydes, ketones, and 11D5. In addition, the rare 9-(5-pentylfuran-2-yl)-nonanoic acid (9F5) was detected in red goji berries after drying.