POSTHARVEST PHYSIOLOGY AND QUALITY MAINTENANCE OF FRESH-CUT PEARS

Abstract

The objective of our research was to investigate the effectiveness of various physical and chemical treatments in delaying deterioration of fresh cut pear fruit slices. Slices cut from ripe 'Bartlett' pears were dipped for 1 minute in 1% CaCl 2 or in distilled water, held in air, air + 5% CO 2 or 0.5% O 2 (balance N 2 ), and then evaluated after 2, 4, 7, and 9 days of storage at 5°C for flesh firmness, flesh color and visual quality. We found that: (A), neither the 0.5% O 2 nor the air + 5% CO 2 treatments had any beneficial effects on retaining flesh firmness or reducing cut surface browning ; (B), CaCl 2 treated slices had significantly less cut surface browning and better firmness retention compared to untreated slices. Compared to the air control, atmospheres of air + 10% CO 2 or air + 20% CO 2 caused accelerated tissue browning and necrosis. These data indicate that pear slices are susceptible to high CO 2 injury, and the symptoms expressed are similar to those observed in whole fruit. We found that an atmosphere of 0.25% O 2 did not effectively reduce cut surface browning of sliced pears. Various concentrations of calcium lactate and/or ascorbic acid were tested on 'Bartlett' pear tissue discs to determine the optimal treatment levels to prevent browning and loss of flesh firmness. We found a combination of 1% calcium lactate and 2% ascorbic acid applied as a dip for 1 minute was the most effective treatment to reduce cut surface browning and firmness loss in pear discs.