Journal
FOOD CHEMISTRY
Volume 131, Issue 2, Pages 397-404Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.foodchem.2011.08.071
Keywords
Alliinase; Allium discolouration; Food processing; Lachrymatory factor; Onion
Funding
- Cooperative State Research, Education, and Extension Service, US Department of Agriculture [2009-34402-19831]
- Vegetable & Fruit Improvement Center, Texas AgriLife Research
Ask authors/readers for more resources
Green discolouration (greening) of macerated garlic products is a major concern in the garlic-processing industry, and is caused by reactions between free amino acids and 2-propenyl 1-propenyl (2-Pe/1-Pe) thiosulphinates in the garlic. Efficacy of freeze-dried fresh onion powder that contains the active onion enzyme lachrymatory factor synthase (LFS) to prevent greening in processed garlic was evaluated. IFS converts 1-propenesulphenic acid to the volatile lachrymatory factor (LF). We hypothesised that this conversion would decrease the production of 2-Pe/1-Pe thiosulphinates, and thus, would reduce the subsequent discolouration of the garlic. Cooked onion powder added to fresh garlic, which was equivalent to adding crude 1-PeCSO, resulted in intensified green discolouration and increased 2-Pe/1-Pe thiosulphinate levels. On the other hand, fresh onion powder added to fresh garlic (0.5 g powder to 100 g fresh garlic) prevented greening and decreased the 2-Pe/1-Pe thiosulphinate levels. Similarly, a crude onion enzyme solution prevented greening in a garlic homogenate. The 2-propenyl 2-propenyl thiosulphinate (allicin) content was inconsistently altered by the addition of onion powder. However, the expected production of IF by the fresh onion powder or enzyme solution was not detected by gas chromatography, possibly due to changes in the sample matrix. This method using fresh onion powder is an effective technique for preventing greening of fresh garlic that does not use artificial food additives or cause safety concerns. (C) 2011 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available