title: Role of precursors on greening in crushed garlic (Allium sativum) bulbs, and its control with freeze-dried onion powder.
abstract: BACKGROUND
  Lachrymatory factor (LF) synthase in onion bulbs reacts with S-1-propenyl-L-cysteine sulfoxide (1-PeCSO), a key compound in garlic greening. In this study, freeze-dried onion powder containing LF synthase was used in treatments to control garlic greening. Prior to the use of freeze-dried onion powder to treat greening garlic bulbs, model reactions were conducted to confirm the reactivity of 1-PeCSO in onion bulbs to garlic greening.
  
  
  RESULTS
  While pink pigments were generated from 1-PeCSO, green pigments were produced from the combination of 1-PeCSO and S-2-propenyl-L-cysteine sulfoxide (2-PeCSO). However, pigments were formed in the systems containing 1-PeCSO, amino acid and alliinase. Even non-greening garlic bulbs stored at 20 °C turned green with the reaction of 200 g L(-1) 1-PeCSO; therefore 1-PeCSO isolated from onion bulbs had the same role as 1-PeCSO in garlic bulbs in terms of greening. Onion bulbs turned green after the addition of 600 g L(-1) 2-PeCSO. The addition of freeze-dried onion powder inhibited garlic greening, and treatment with 15 g kg(-1) onion powder gave the best storage stability of crushed garlic bulbs.
  
  
  CONCLUSIONS
  The addition of freeze-dried onion powder inhibited the greening in crushed garlic bulbs, and treatment with 15 g kg(-1) onion powder gave the best storage stability of crushed garlic bulbs.
authors.affiliation: World Institute of Kimchi, Research and Development Division, 516 Baekhyun-dong, Bundang-gu, Sungnam-si, Gyeounggi-do 463-746, Korea.
authors.forename: Jungeun
authors.initials: J
authors.lastname: Cho
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Lee
authors.forename: Kil Sun
authors.initials: KS
authors.lastname: Yoo
authors.forename: Seung Koo
authors.initials: SK
authors.lastname: Lee
mesh_terms: D003545:Cysteine / Q000031:analogs & derivatives / Q000737:chemistry; D061353:Food Storage; D005524:Food Technology; D005612:Freeze Drying; D005737:Garlic / Q000737:chemistry*; D019746:Intramolecular Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D019697:Onions / Q000737:chemistry*; D010860:Pigments, Biological; D018517:Plant Roots; D013454:Sulfoxides / Q000737:chemistry
chemical_list: C467561:1-propenylcysteine sulfoxide; D010860:Pigments, Biological; D013454:Sulfoxides; D019746:Intramolecular Oxidoreductases; C570346:lachrymatory factor synthase, Allium cepa; D003545:Cysteine