SENESCENCE OF BROCCOLI BUDS IS RELATED TO CHANGES IN LIPID-PEROXIDATION

Chlorophyll (Chi), total soluble protein, lipoxygenase (LOX) activity, C-18 polyunsaturated fatty acid. (PUFA), C-18 PUFA hydroperoxides, an d total fatty acid declined and thiobarbituric acid-reactive substance s (TBA-RS) increased in senescing broccoli flower buds during postharv est storage of broccoli florets at 5 degrees C over 96 h. The nonpacka ged storage treatment resulted in a significant decrease in moisture, Chl, soluble protein, PUFA, and LOX activity and an increase in TBA-RS . Modified atmosphere packaging (MAP) and automatic misting (AM) treat ments maintained Chl and soluble protein. MAP and AM storage reduced l osses in PUFA and LOX activity and also reduced increases in TBA-RS fo r up to 96 h of storage. Further analysis of the data showed that a co rrelation existed between deterioration indices and lipid peroxidation (LP) parameters and the changes in LP indices preceded Chl losses in senescing broccoli buds. These results indicate a relationship between changes in LP and broccoli bud senescence.