Levels of preservatives (sulfite, sorbate and benzoate) in New Zealand foods and estimated dietary exposure

The theoretical risk of exceeding the Acceptable Daily Intake (ADI) for sulphites has mostly been examined on the basis of a worst-case scenario. In order to examine the real situation the determination of residue sulphite levels in ready-to-consume foods is required. The aim of this paper is to assess the actual sulphite content of diets obtained from a combination of realistic meals high in sulphite-containing foods. Food products available in Italy containing added sulphites were identified. Overall, 211 samples of foods and beverages (including 85 samples of wine) were collected. The determination of sulphite residues was carried out on the foods which were prepared according to normal domestic practice. It was shown that the diets obtained from these foods would lead to an intake of 23 mg/day in children and 50 mg/day in adults (both slightly above the ADI for respectively a 30 kg child and a 60 kg adult). Among all sulphite-containing foods, the highest contributors to the intake were dried fruit and wine, both ingested without further treatment. The analysis of specific consumption data confirmed the existence of a risk of exceeding the ADI related to sulphite residue levels in wine.

The acceptable or tolerable daily intake (ADI or TDI) for food additives and contaminants is usually derived from chronic animal toxicity studies. The basis for the ADI or TDI is the determination of the no-observed effect level (NOEL) for the most sensitive toxicological effect in the most sensitive laboratory species. This "safe intake" for animals is then divided by a safety or uncertainty factor to allow for possible differences between the test species and humans and for possible differences within the human population. Therefore, the ADI or TDI is related to a toxic effect in the test species which is considered to be of relevance to humans. Any risk to humans who exceeded the ADI or TDI can only be assessed by reference to the dose-response for the toxicity giving rise to the NOEL. The duration of a human intake in excess of the ADI should also be considered in relation to the protocol used in such animal studies.