| Abstract
| - The content of aroma compounds and the catalytic activity of lipoxygenase (LOX), alliinase,hydroperoxide lyase (HPL), and alcohol dehydrogenase (ADH) were analyzed in unblanched andblanched 15-mm leek slices packed in atmospheric air (21% O2) or 100% nitrogen (0% O2) threetimes during 12 months of frozen storage (12 M). The total amount of sulfur compounds and the totalamount of aldehydes were greatly influenced by storage time, atmosphere, and blanching [concentration of sulfur compounds in fresh unblanched (UNB) slices = 1.35 mg/L, fresh blanched (B) slices =1.09 mg/L, UNB 21% O2 12 M = 0.656 mg/L, UNB 0% O2 12 M = 2.11 mg/L, B 21% O2 12 M = 1.14mg/L, B 0% O2 12 M = 1.59 mg/L]. B 0% O2 was closest to the original ratio between sulfur compoundsand aldehydes after 12 months. The activities of HPL and alliinase were totally lost after 12 months,and ADH showed minimal activity, whereas LOX (UNB 0% O2) showed ∼25% of the original activity.LOX was the most and HPL the least heat labile enzyme investigated. Keywords: Leek; flavor; frozen storage; lipoxygenase; hydroperoxide lyase; alcohol dehydrogenase;alliinase; packaging atmosphere; blanching
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