Q01050: The detection of added meat products in processed vegetarian foods

Study Duration: August 2001 to July 2002

Contractor: Central Science Laboratory

Convenience vegetarian foods form an increasing part of the retail market. Methods to determine whether meat or meat by-products have been used in the preparation of vegetarian foods are needed for future surveys. The use of cholesterol analysis to determine contamination of vegetable fats and oils with animal products has been proposed based on the fact that cholesterol is by far the major component (98%) of animal fats and is virtually absent from vegetable materials. This work will also compliment work in Q01049 and the contractors will be in close liaison.

The project will characterise and quantify cholesterol, hydrogenated cholesterol and hydrogenated cholesterol dehydration products in vegetarian and meat ingredients, excluding ingredients such as milk, cheese and egg. The project will take into account the fact that cholesterol is present in some vegetable fats, particularly palm oils. However, whereas levels of sterols in vegetable fats are generally between 100 and 500 milligrams per 100 grams, in palm oil the sterol content is much lower at less than 1 milligram per kilogram. It may be estimated therefore that the cholesterol content of vegetable oil containing palm oil will not exceed 0.1 milligram per kilogram. However, a complication to the application of cholesterol analysis is the fact that before use as foodstuffs most animal fat products are refined by bleaching and/or deodorising and sometimes hydrogenation. In addition, meat based ingredients intended for addition to processed foods are likely to have undergone conditions which will cause the cholesterol to be changed. The data produced will hopefully be used to set acceptable limits for cholesterol and its processing products (cholestane, cholestenes and cholestanol) in vegetarian foods. Limits of detection will be estimated for individual analytes, and canonical variant analysis will be applied. Finally, a low-cost screening technique might be established to detect added meat-derived fats in vegetarian foods.

There is an expectation by the public that food labelling is accurate and that techniques are available to confirm the composition of food and food ingredients. Methods to determine whether vegetable fats and oils have been contaminated with animal fats are needed for future surveys. Cholesterol is the major sterol component of animal fats but is virtually absent from vegetable fats and so could be used as a reliable marker for the presence of animal products.

This project examined the cholesterol, phytosterol and sterol degradation product composition of 35 animal fats and 50 vegetable fats.

The resultant data was fed into a statistical model to produce a set of mixtures containing a range of animal fat levels in oils and fats of vegetable origin.

This model was used to estimate levels of detection for animal fat contamination of vegetable fats and oils.

It was shown that the method could detect approximately 95% of cases where there was a 10% level of animal fat contamination and 90% of cases where there was a 5% level of animal fat contamination.

The final report will be available from the Food Standards Agency library once papers resulting from this project have been published in peer-reviewed scientific journals.

Contact: For any enquiries concerning this research project, please contact the relevant Programme contact or email science@foodstandards.gsi.gov.uk