Formation of aroma compounds during long-term frozen storage of unblanched leek (Allium ampeloprasum Var. Bulga) as affected by packaging atmosphere and slice thickness.
Content of aroma compounds and catalytic activity of lipoxygenase (LOX), hydroperoxide lyase (HPL), and alcohol dehydrogenase (ADH) were analyzed in 4- and 15-mm unblanched leek slices packed in atmospheric air (4- and 15-mm) or 100% nitrogen (N) (only 15-mm) seven times during 12 months of frozen storage (12M). Total amount of sulfur compounds was influenced by storage time, slice thickness, and atmosphere (concentration in fresh 4-mm slices = 17.8 mg/L, 4-mm 12M = 3.48 mg/L, fresh 15-mm slices = 2.48 mg/L, 15-mm 12M = 0.418 mg/L and 15-mm N 12M = 1.81 mg/L). The 4-mm slices significantly developed the most aldehydes after 12M (total amount = 9.28 mg/L) compared to 15-mm 12M (6.49 mg/L) and 15-mm N 12M (4.33 mg/L). LOX activity is positively influenced by nitrogen packaging, and HPL activity is influenced by slice thickness, whereas ADH is unaffected by both parameters.
Department of Dairy and Food Science and LMC, Centre of Advanced Food Studies, The Royal Veterinary and Agricultural University, Rolighedsvej 30, 1958 Frederiksberg C, Denmark. gni@kvl.dk
Ghita Studsgaard
GS
Nielsen
Lone Melchior
LM
Larsen
Leif
L
Poll
D000426:Alcohol Dehydrogenase / Q000378:metabolism; D000446:Aldehyde-Lyases / Q000378:metabolism; D000490:Allium / Q000737:chemistry* / Q000201:enzymology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D005615:Freezing; D008084:Lipoxygenase / Q000378:metabolism; D009812:Odorants / Q000032:analysis*
D003577:Cytochrome P-450 Enzyme System; D000426:Alcohol Dehydrogenase; D008084:Lipoxygenase; D000446:Aldehyde-Lyases; C054540:hydroperoxide lyase