N08012: Development and validation of an HPLC method for the determination of folate in food

Study Duration: April 1999 to December 2002

Contractor: Laboratory of the Government Chemist

Folate and folic acid are forms of a water-soluble B vitamin. Folate is a generic term for a number of compounds, which occur naturally in food. They are found in most foods, with legumes, green vegetables, liver and yeast being considered good sources. Breakfast cereals and some other foods may be fortified with folic acid, the synthetic form of this vitamin.

Folate is essential for many body processes including the production of new cells. Most people obtain adequate folate intake from their general diet but deficiency can occur in certain groups such as people on medication that interferes with the action of folate, or those with medical conditions where the body's use of folate may be impaired. Folic acid is very important for all women who may become pregnant. Adequate folate intake before and after conception protects against a number of congenital malformations including neural tube defects in the developing foetus. Women who are planning a pregnancy are recommended to eat more folate-rich foods and to avoid overcooking them and to take a daily 400 microgram folic acid supplement until the 12th week of pregnancy. There is also some evidence that increasing the amount of folate in the diet may reduce the risk of cardiovascular disease in the population.

In order to assess the intake of folate from the diet, it is necessary to have reliable methods for the determination of the folate content of foods. Total folate has been determined with varying degrees of accuracy, for many years while data on individual folate forms is more recent and methods are still being improved. Some types of folate are more readily absorbed and used by the body than others. It is therefore important to be able to determine the amount of each different type of folate in foods.

High performance liquid chromatography (HPLC) is an analytical technique that is capable of separating and quantifying the different forms of folate. However, there remain significant problems in applying this technique to all foods because of the difficulties in extracting folates quantitatively from other food components. This research sought to develop and test an HPLC procedure, which could be used reliably to determine the folate content of a range of foodstuffs.

The project further developed a method devised under earlier Agency funding, and compared it with a recognised microbiological method of measuring total folate. Data obtained using this procedure will improve the knowledge of the types and amount of folates in foods, which will be useful in research into how the different forms are absorbed and processed in the body and will allow more accurate assessment of the amount of folate in our diets.

The final report is available from the FSA Library and Information centre. To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency (020 7276 8181/8182 or at library&info@foodstandards.gsi.gov.uk).

Contact: Susan Church
Tel: 020 7276 8911
Email: susan.church@foodstandards.gsi.gov.uk