What Is Sulphur Dioxide on Dried Fruit?
Sulphur dioxide, also known as sulphites (E220-E228), is a chemical compound used in food preservation for centuries. In dried fruit production, it serves several key purposes:
- Prevents Browning: It acts as an antioxidant, stopping the fruit from oxidizing and turning an unappetizing brown colour, especially in light-coloured fruits like apricots and golden raisins.
- Inhibits Microbial Growth: Its antimicrobial properties prevent the growth of bacteria, yeasts, and moulds, which extends the product's shelf life.
- Maintains Appearance: By preventing discolouration and rotting, it keeps the dried fruit looking fresh and visually appealing to consumers.
The FDA requires labelling if the sulphite concentration exceeds 10 parts per million, making it easier for sensitive individuals to identify and avoid products containing the additive.
Is It Dangerous for Most People?
For the vast majority of healthy people, consuming sulphur dioxide on dried fruit in typical amounts is not considered harmful. The human body can metabolize and excrete sulphites through urine, minimizing any potential adverse effects. International food safety authorities, including the Joint Food and Agriculture Organization / World Health Organization Expert Committee on Food Additives (JECFA), have evaluated its safety and concluded it is safe when used in line with Good Manufacturing Practice.
Health Risks for Sensitive Individuals
While generally safe, a small but significant portion of the population is sensitive to sulfites. This sensitivity can cause a range of adverse reactions, with asthmatics being particularly vulnerable.
Asthma and Respiratory Issues
For individuals with asthma, particularly those with steroid-dependent or chronic asthma, sulphites can trigger allergic-like symptoms, including:
- Wheezing
- Chest tightness
- Coughing
- Shortness of breath
Some research suggests that 5-10% of chronic asthmatics are hypersensitive to sulphites. The mechanism is thought to involve the gas irritating airways that are already hypersensitive.
Other Allergic-like Reactions
Beyond respiratory issues, sulphite sensitivity can cause other symptoms that may be mistaken for a true allergy:
- Skin rashes and hives (urticaria)
- Dermatitis
- Facial swelling
- Gastrointestinal problems such as abdominal pain, nausea, and diarrhoea
- Headaches
In very rare cases, a severe, life-threatening anaphylactic reaction can occur, making it crucial for sensitive individuals to avoid sulphite-containing products.
Sulfured vs. Unsulfured Dried Fruit
Dried fruit comes in both sulfured and unsulfured varieties. Understanding the differences helps in making an informed choice, especially for those with sensitivities.
| Feature | Sulfured Dried Fruit | Unsulfured Dried Fruit |
|---|---|---|
| Appearance | Bright, vibrant colours (e.g., orange apricots) | Darker, more natural, and sometimes less uniform colour |
| Shelf Life | Longer due to preservative properties | Shorter, requires more careful storage |
| Taste & Texture | Potentially chewier and less flavourful | More intense, concentrated natural fruit flavour and slightly different texture |
| Nutrient Content | May lose some heat-sensitive nutrients during processing | Generally retains more original nutrients, especially Vitamin C |
| Allergen Risk | Potential for adverse reactions in sensitive individuals | No risk of sulphite-related reactions |
| Cost | Often less expensive due to processing methods | Can be more expensive due to shorter shelf life and specialised handling |
How to Reduce Sulphur Dioxide Intake
For those who prefer to consume dried fruit with reduced sulphite levels, there are several methods to consider:
- Choose Unsulfured or Organic Varieties: Organic dried fruits are prohibited from containing synthetic preservatives like sulphur dioxide, making them a safe choice. Look for product labels explicitly stating 'no added sulfites'.
- Wash and Soak: Since sulphites are water-soluble, soaking and washing dried fruit in warm water can significantly reduce their residual content. A study found that washing dried apricots removed about 16% of sulphites, while boiling could remove over 40%. Soaking for 20-30 minutes and rinsing well is a common recommendation.
- Soak in Acidic Solution: Some sources suggest that soaking dried fruit in a solution of warm water and lemon juice or citric acid can help accelerate the removal of sulphites. This is believed to increase the solubility of sulphites. A 1% lemon juice solution is one method mentioned.
Conclusion
Sulphur dioxide on dried fruit is a safe food additive for the majority of the population and plays a critical role in preserving the product's quality and appearance. However, its consumption poses a real health risk for a small percentage of the population, particularly those with asthma or sulfite sensitivity, who can experience a range of symptoms from mild respiratory issues to severe anaphylaxis. If you are a sensitive individual, or simply prefer to avoid the additive, opting for unsulfured or organic dried fruit is the safest option. If you do consume sulfured products, washing and soaking them can help reduce the residual sulphite content. Being mindful of your body's reaction and checking product labels is key to ensuring a safe and healthy snack choice.
For more information on sulfite sensitivity, consult the guidance provided by the Australasian Society of Clinical Immunology and Allergy (ASCIA).
Considerations for Different Groups
- General Consumers: Healthy individuals without sensitivities generally do not need to worry about sulphur dioxide in dried fruit, as it is considered safe in typical consumption levels.
- Asthmatics: Individuals with asthma are at a higher risk of adverse reactions and should exercise caution. Many may need to actively avoid sulphited products.
- Parents and Children: Although studies on children are less conclusive, some research indicates they may be more susceptible to sulphite sensitivity. It's advisable for parents to monitor intake and symptoms.
- Individuals with Skin Conditions: Those with conditions like eczema may find their symptoms aggravated by sulphites and should consider limiting or avoiding them.
- Long-Term Consumption: Some regulatory bodies have noted uncertainties regarding Acceptable Daily Intake (ADI) levels, especially for high consumers. Moderation is always a wise approach with any food additive.
Remember to listen to your body and consult a healthcare provider if you suspect a sulfite sensitivity or experience any adverse reactions.
