Enzymes associated with blackheart development in pineapple fruit
Yuchan Zhou , Janelle M. Dahler, Steven J. R. Underhill and Ron B. H. Wills
Food Chemistry Volume 80, Issue 4 , April 2003, Pages 565-572
2003
บทคัดย่อ
The involvement ofbrowningenzymes, polyphenoloxidase (PPO), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) in blackheart development was investigated in pineapplefruit(Ananas comosus, Smooth Cayenne) following low temperature storage. An increase in PPO activity was related to the incidence of blackheart symptoms, both temporally and spatially.Fruitmaturity significantly affected blackheart susceptibility; immature and over-maturefruitsdeveloped less blackheart injury than maturefruit.The effect of maturity on blackheart susceptibility was highly correlated to the response of PPO activity to chilling. POD showed no significant change after chilling. Enhanced PAL activity was observed during chilling at 6, 13 and 18 °C. Chilling (6, 13 and 18 °C) also inhibited the increase of ascorbate peroxidase activity observed in thefruitstored continuously at 25 °C, but had less effect on catalase activity. The results indicate that the development of blackheart symptoms in pineapplefruitresults from the disturbance of a number of metabolic processes that occur at sub-ambient temperatures.