Respiratory activity and phenolic compounds in pre-cut celery

Abstract: The effect of temperature on respiratory activity and total phenol and flavonoid contents in pre-cut celery was assessed within the 24h following this minimal processing. To this end, celery petioles were cut as strips, conditioned in crystal polyethylene terephthalate trays covered with PVC film and stored at 0, 10 and 20°C. Samples were removed at 0, 2, 4, 6 and 24h after processing to analyse respiratory activity and concentrations of total phenols and flavones. For the samples kept at 0°C for 24h, chlorogenic acid was also determined, along with total flavonoids and antioxidant power. At this temperature, the total phenol contents remained basically constant, though at 10°C it increased considerably two hours after applying the cutting stress. At 20°C the increase observed was less important. The flavones, identified by HPLC in pre-cut celery were apigenin and luteolin, whose concentrations also increased between two to six hours after processing. However, exposure for 24h at 0°C produced a considerable decrease in total flavonoids. [Copyright &y& Elsevier]