In vitro chlorophyll degradation in stored broccoli (Brassica oleracea L. var. italica Plen.) florets
Naoki Yamauchi, Kaori Harada and Alley E. Watada
Postharvest Biology and Technology Vol: 12 Issue: 3 Pages: 239-245.
1997
บทคัดย่อ
In vitro chlorophyll (Chl) degradation in broccoli (Brassica oleracea L. var. italica Plen.) florets was studied by HPLC analysis of the degradative products. With the degradation of Chl, chlorophyllide a (Chlide a) and phaeophorbide a (Phb a) increased gradually in the reaction mixture containing the broccoli extract. This was followed by the formation of pyrophaeophorbide a (Pyro-Phb a) after 2 h of reaction time. 132-hydroxychlorophyll a (Chl a-1) showed minimal change during the reaction. Chl a degradation and Chlide a formation decreased significantly in an extract of yellow broccoli florets during 4 days storage at 15°C. Pyro-Phb a formation also decreased gradually, but Chl a-1 formation did not decrease during storage. Thus, in an in vitro system of extracted broccoli florets, Chl a was degraded initially to Chlide a or Chl a-1. Chlide a subsequently was degraded to Pyro-Phb a through Phb a. Chl a-1 and Pyro-Phb a could be finally degraded to colourless low molecular weight compounds.