| Abstract
| - The occurrence of methional in fresh orange juice, and possible occurrence of β-damascenone inheated orange juice, has been previously suggested. Here we report on the occurrence of 2-methyl-3-furanthiol in the headspace, collected by solid-phase micro-extraction, of fresh, pasteurized, andstored orange juice. The contents of 2-methyl-3-furanthiol and methional were quantified, and therelative level of β-damascenone was estimated, in the headspace of fresh, pasteurized, and storedorange juices using the nasal impact frequency (NIF) and surface of NIF (SNIF) GC−Olfactometryprocedure. 2-Methyl-3-furanthiol concentrations were 2 ng/L in fresh and pasteurized Shamuti orangejuice, and 270 ng/L in stored juice of the same variety. Methional concentrations were 550, 830,and 11550 ng/L in fresh, pasteurized, and stored pasteurized juices, respectively. β-Damascenonecontent appeared to have increased during pasteurization and storage. Aroma-similarity experimentsstrongly suggest that 2-methyl-3-furanthiol and methional, at the levels found in stored orangejuice (21 days at 35 °C), contribute to stored orange juice off-flavor. Keywords: 2-Methyl-3-furanthiol; methional; β-damascenone; orange juice; NIF; SNIF; GC−O;off-flavor; Citrus sinensis
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