Heat shock reduces browning of fresh-cut celery petioles
Julio G. Loaiza-Velarde, Mary E. Mangrich, Reinaldo Campos-Vargas and Mikal E. Saltveit ,
Postharvest Biology and Technology Volume 27, Issue 3 , March 2003, Pages 305-311
2003
บทคัดย่อ
Preparation of 5 mm segments of celery petioles induced an increase in the activity of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5), and subsequent tissue browning potential (absorbance of a 70% methanol tissue extract at 320 nm g−1 FW). The level of constitutive and wound-induced PAL activity was higher in vascular than in cortex tissue, and lowest in epidermal tissue. Heat shocking excised petiole segments (e.g. 50 °C for 90 s) significantly reduced the rise in wound-induced PAL and browning potential. Pithiness of the petiole segments did not alter the effectiveness of the heat shock treatments, nor was pithiness enhanced by the treatments. As storage life was extended, however, decay and the protrusion of vascular bundles from the cut ends of the segments became important factors in limiting shelf-life.