Sulphur dioxide in longan

Longan is a seasonal fruit commonly sold in summer. After harvesting, farmers or food manufacturers may treat longan with chemicals to prolong it's shelf-life. Sulphur dioxide is one of the chemicals used to prevent skin browning and post-harvest disease of longan. This treatment is a common practice in some countries, like Thailand and China. However, exposure to sulfur dioxide may cause allergy ¹ in susceptible individuals. To reduce intake of sulfur dioxide, the following precautionary measures should be undertaken.

When we buy longan:

• ƒÜ Buy longan only from reputable shops
• ƒÜ Avoid buying longan with unreasonably low price

When we store longan:

• ƒÜ Separate longan from other food, like raw meat, to prevent cross-contamination
• ƒÜ If refrigeration is applied, consume refrigerated longan within 2 weeks
• ƒÜ If refrigeration is not applied, consume longan within a few days

When we eat longan:

• ƒÜ Discard any damaged longan
• ƒÜ Wash longan thoroughly and gently rub longan under running water before eating
• ƒÜ Avoid washing more than enough longan in one go
• ƒÜ Avoid biting the husk of longan
• ƒÜ Wash hands thoroughly after handling longan and before eating
• ƒÜ After removing the husk, eat the flesh as soon as possible
• ƒÜ Avoid eating too much and take a balanced diet

When we handle leftovers:

• ƒÜ Discard any flesh left out at ambient temperature for more than 2 hours
• ƒÜ Refrigerate and consume the flesh as soon as possible

^1. Sulphur dioxide can induce allergic reactions like asthma in some individuals.

Photos are provided by Consumer Council