Characterization of hot pepper spice phytochemicals, taste compounds content and volatile profiles in relation to the drying temperature

The aim of this study was to investigate how the use of increasing hot air drying temperature affects the phytochemical content and the volatile profile of hot pepper spice. A comprehensive characterization of spice from Italian varieties dried at different temperatures (50, 57, and 64 degrees C) was performed, including general quality indexes, phytochemicals, functional properties, and volatile profile. In dried peppers capsaicinoids were completely retained; a remarkable loss of ascorbic acid was observed, while carotenoids amount decreased of about 39%. The retention of tocopherols was higher at 50 and 57 degrees C. The Folin Ciocalteu index showed a steep decrease after drying, but the opposite trend was observed when it was measured using a correction factor to exclude the ascorbate contribution. The volatile profile changed with the increase in drying temperature, due to the production of Strecker aldehydes, methional, and tetramethylpyrazine, and a reduction in esters, terpenoids, and 2-isobutyl-3-methoxypyrazine.