TEMPERATURE INFLUENCED LIPID-PEROXIDATION AND DETERIORATION IN BROCCOLI BUDS DURING POSTHARVEST STORAGE

The effect of temperature on lipid peroxidation (LP) and deterioration of broccoli flower buds was investigated during postharvest storage. Fresh broccoli florets were packaged in microperforated polymeric film bags and stored under different temperatures (2, 13, and 23 degrees C ) over 144 h. LP was determined by measuring polyunsaturated fatty aci ds (PUFA), thiobarbituric acid-reactive substances (TBA-RS) and lipoxy genase (LOX) activity. Changes in chlorophyll (Chi) levels, moisture a nd total soluble protein were used to assess broccoli deterioration. I ncreased temperature significantly accelerated total Chi (TChl) and so luble protein losses without reduction in moisture content. Temperatur e abuse at 13 and 23 degrees C also resulted in reduced PUFA and LOX a ctivity with increased TBA-RS values compared to those in the 2 degree s C-treated buds over storage. By the end of storage, TChl, proteins, PUFA and LOX activity decreased by >70% in broccoli buds stored at 23 degrees C. TBA-RS values increased 10-fold. Treatment of samples at 2 degrees C maintained quality and prevented changes in deterioration an d LP parameters. The current investigation shows that increases in tem perature accelerate the deterioration and LP of broccoli buds and furt her demonstrates that there is a relationship between LP and deteriora tion during postharvest storage of broccoli.