DETERMINATION AND COMPARISON OF FOLIC ACID IN FORTIFIED WHEAT FLOURS AND BREADS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) IN THE URMIA CITY

Folate has been identified as one of the most important water-soluble B vitamins for normal metabolic function and it is essential for normal human cell division and cell growth. Since humans cannot synthesize folates, they must obtain from dietary sources. The most important dietary sources of folates are fortified foods, and cereal products with folate content of 50-200 µg/100 g. In Iran the majority of people consume bread as an ideal food, because of the reasonable price and availability. The objective of this study was to describe a method for determination of folic acid in wheat flours and breads.
The method consisted of several procedures, including an extraction technique, oxidation of folic acid to increase fluorescent properties, and a modified HPLC with fluorescence detection method. Thirty enriched flours and thirty bread samples were purchased from the local baker markets in Urmia.
The standard curve for folic acid passed through the origin and was liner over the range 0.1-8 µg/L. The peak of folic acid appeared as sharp with retention times of 1.12 minutes. The accuracy of the method ranges between 99.2% and 103.7% for intra-day analysis and 98.8% and 106.9% for inter-days analysis. The limit of detection for folic acid was 0.03µg/L. The mean concentration of folic acid was 102 µg and 85 µg per 100 gram of flour and bread, respectively.
This work is a preferred method for folic acid analysis because it is rugged, fast, specific and sensitive. Estimation of folic acid in wheat flour was less than those based on calculations as done for enriched flours. There was 17% decrease of folic acid from flour to bread stage.