- L Tait and F Kruger
- Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200
- 1998
Sulphur fumigation is the standard postharvest method used to treat South African export litchis. Due to increased opposition to the use of sulphur by some importing countries, research on alternative methods is ongoing at the ITSC. During the 1995/6 season four trials were conducted in this regard.
Summary:
- Sulphur fumigation is the standard post-harvest treatment for South African export litchis, but opposition to sulphur use by some importing countries has led to research for alternative methods at the Institute for Tropical and Subtropical Crops (ITSC).
- Four trials were conducted during the 1995/6 season focused on alternative treatments to sulphur fumigation.
- The first two trials studied the use of acids and low-concentration sodium metabisulphite combined with various coatings.
- Results suggested that citric acid may help retain litchi skin color and resist fungal infections, though findings are preliminary and further research with food industry acids, antioxidants, and edible coatings was planned for the next season.
- The third trial tested steam combined with hydrochloric acid, a fungicide, and an anti-transpirant; initial visual results were promising but storage potential remains an issue.
- Further research on this topic is recommended to focus on heated fungicide imazalil and possibly modified atmosphere packaging rather than coatings.
- The fourth trial involved hydro cooling of fruit post-harvest and packing in boxes with reduced ventilation compared to the standard packaging.
- Hydro cooling showed benefits by reducing mass loss during storage, but the cost-effectiveness of hydro-cooler installation and operation needs further evaluation.
- Boxes with less ventilation did not significantly improve fruit quality, suggesting retention of the current packaging system.
- This article provides insights into ongoing efforts to find alternatives to sulphur fumigation and improve the post-harvest handling of export litchis in South Africa