ISHS Acta Horticulturae 518: XXV International Horticultural Congress, Part 8: Quality of Horticultural Products
NON-CHEMICAL DISINFESTATION: A FREEZING APPROACH |
| Authors: | C. Chervin, S. Kreidl, A. Hamilton, S. Whitmore |
| Keywords: | Pyrus communis, apples, browning, colour, disinfestation, firmness, freezing, Malus domestica, pears, postharvest, sensory analysis |
| Abstract:
The presence of insect pests in pome fruit can limit access of produce to overseas markets. Non-chemical disinfestation may become a marketing advantage (healthy fruit) and a valuable alternative to methyl bromide. Previous work has shown that combinations of controlled atmosphere (CA) and cold storage are effective in controlling some insect pests. Freezing has never been tested as a disinfestation treatment as injuries to fruit are known to occur. However a short pulse of freezing temperatures may shorten the cold storage period necessary to achieve effective disinfestation using the methods mentioned above. Firstly we tested the effect of such a freezing pulse on fruit quality. Packham's pears and Pink Lady apples were subjected to short periods of freezing at -5°C (2, 4 or 6 days for pears, and 1, 2 or 3 days for apples). The fruit were then exposed to controlled atmosphere (1 to 2 kPa oxygen) and cold storage at -1°C for 2, 4 or 6 weeks. Finally, the fruit were stored under air for 3 weeks at +1°C to simulate conditions during sea freight. Fruit were then evaluated for their quality (taste, firmness, colour, internal and skin injury). No significant difference was found in the consumer acceptance of treated apples and pears (pears frozen for 6 days were not tested). However more than one day at -5°C produced unacceptable levels of visual damage (mainly internal and external browning) in both apples and pears. The effectiveness of 24 h at -5°C on the mortality of leafroller larvae is currently being tested. | |
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