水産ねり製品の褐変について-VI

Enterobacter cloacae UFF-107株による褐変機構

抄録

1. E. cloacae UFF-107 was inoculated into culture media containing 10% glucose and 5% Na-glutamate. The media were incubated at 30°C for 0, 1, 3, 5, 7 and 10 days respectively. It was observed that a substance showing optical absorp-tion at 490mμ was produced in the cultures during incubation.
2. The culture fluid was spotted on a thin-layer chromatogram (Silicagel F₂₅₄) and developed by a solvent system containing n-butanol, acetone, and water in the ratio 4:3:1. Brown spots with Rf value 0.05 were detected when the chromatograms were air-dried and treated with a 20% glycine solution.
3. E. cloacae UFF-107 was inoculated into media containing 5% glucose. The media were incubated at 30°C for 5 days and then heated at 100°C for 10 minutes. After the heating, the media turned brown. No spots with an Rf value of 0.05 were recognized on the chromatogram.
4. The media inoculated with E. cloacae UFF-107 were passed through an Amberlite IRA 400 (a Cl type) column and eluted with 1 N-HCl. Various amino acids and proteins were added individually to the eluates which turned brown when they were incubated at 37°C for 2 hours.
5. When eluates containing glycine were incubated at 0-37°C for 2 hours, they turned brown at 25-37°C.