- M H Schoeman and F J Kruger
- ARC-Institute for Tropical and Subtropical Crops, Private Bag Xtt208, Nelspruit 1200, South Africa
- 2004
Smartfresh (1-methylcyclopropene; 1-MCP) is an ethylene inhibitor used by, amongst others, the apple and avocado industries. The present study was conducted to establish whether 1-MCP has a role to play in the South African litchi export industry. To do this, 1-MCP was applied to sulphur fumigated as well as to sulphur free HLH Mauritius litchi fruit.
1-MCP was not found to have an effect on sulphur fumigated fruit. However, it did have a positive effect on sulphur free litchis washed with a disinfectant and stored in modified atmosphere bags. The addition of 1-MCP was found to significantly reduce the incidence of fungal infections. The results further suggested that it is most effective when placed directly into the bags (compared to treating the fruit in a cold room prior to packing).
Further research should include the evaluation of Smartfresh with fruit of different maturity stages and it should also be tested on the McLean’s Red cultivar.
Summary:
- Smartfresh (1-methylcyclopropene, 1-MCP), an ethylene inhibitor used in apples and avocados, was tested for its potential benefit in the South African litchi export industry, focusing on both sulphur-fumigated and sulphur-free HLH Mauritius litchi fruit.
- 1-MCP showed no effect on conventionally sulphur-fumigated litchis in terms of shelf life or color enhancement.
- For sulphur-free litchis treated with disinfectant and stored in modified atmosphere (MA) bags:
- 1-MCP significantly reduced fungal infections, especially when applied directly inside MA bags rather than as a pre-treatment in drums.
- Best results were from placing 1-MCP directly in the bag, achieving up to two days of infection-free storage during shelf life at 13°C; significant, but less effective, results were seen by day five.
- Fruit color was better preserved in bag-treated fruit due to reduced desiccation compared to drum-treated fruit.
- On sulphur-free litchis, 1-MCP pre-treatment in drums reduced fungal growth for about two days during shelf life, but rapid spoilage occurred thereafter.
- In trials where 1-MCP was used with fumigation (applied either before or after sulphur treatment), there was no additional benefit over fumigation alone for controlling fungal growth or enhancing fruit color.
- Recommendations for future research include:
- Testing if moving treated fruit from bags to punnets after shipping prolongs shelf life.
- Investigating if adding 1-MCP directly to punnets offers further improvement.
- Exploring the use of slow release 1-MCP formulas.
- Defining effective maturity limits for 1-MCP application.
- Evaluating 1-MCP’s effectiveness on the McLeans Red cultivar, a difficult variety for postharvest quality.