Analytical Report - Canned fruit

Canned fruit is a popular choice for consumers and a portion can contribute to the recommended minimum of 5 portions of fruit and vegetables a day.

High levels of tin in food can cause poisoning and as a result The Contaminants in Food Regulations 2006 specify a maximum of 200mg/kg of tin in canned foods. The amount of tin depends on a number of factors e.g. the type and acidity of the food, the time and temperature of storage and the presence of air. Cans often have an inner lacquer layer to prevent corrosion and the tin from leaching into the food.

A survey conducted by Hampshire and Kent Scientific Services looked at the levels of tin in 111 canned fruit in juice or syrup samples submitted by 8 trading standards departments in the South including Kent County Council.

Summary of results

None of the samples exceeded the maximum permitted level. The average for all 11 samples was 58mg/kg, well below the maximum limit. Low levels of tin were found in 76% of the samples.

The highest level was found in a sample of tinned oranges. Citrus fruits and pineapples are relatively acidic so this is not unexpected. Neither were the average results that showed the highest average values to be for grapefruit, orange and fruit cocktail (which typically have a high citrus fruit and pineapple content).

Berries, figs and rhubarb had either no tin or very low levels. This was unexpected for rhubarb, another acidic food, but indicates how lacquering can prevent leaching.

The ‘age’ of the product and the medium (juice or syrup) were not considered in this sample to be relevant factors to the level of tin found.

Lacquering does reduce the breakdown of the tin. If the can is dented this can damage the lacquer. None of the samples tested were of dented cans but consumers are advised to be cautious in eating food from damaged cans particularly if the food is acidic.

Report Date: May 2007