Folate content of Norwegian and Swedish flours and bread analysed by use of liquid chromatography–mass spectrometry

Liquid chromatography–mass spectrometry (LC–MS) was used to determine folate profiles for various flours and bread from Norway and Sweden. The following ranges in total folate (expressed in μg folic acid equivalents/100 g fresh weight (FW)) were found in Norwegian/Swedish samples: sifted wheat flour (14–20/4–7), wholegrain wheat flour (34–47/20–40), wheat bran (94/109), sifted rye flour (12–30/26–31), wholegrain rye flour (23–50/48–79), rolled oats (21/26), oat bran (27/46), soft bread (17–33/14–40), and crisp bread (40–80, all from Sweden). Generally, Norwegian sifted and wholegrain wheat flours were richer in folate compared with Swedish samples. Conversely, Swedish rye flours were richer in folate than Norwegian samples. Folate content in bread was slightly higher in Swedish samples, especially for crisp bread. The major folate forms found in cereals were 5-HCO-H4folate, 10-HCO-H4folate and 5-CH3-H4folate. A higher content of 5-CH3-H4folate was found in bread than in flour, due to yeast; indeed, 45–70% of the folate found in bread was estimated to originate from bakerʹs yeast. Among the breads, those with the highest folate content were crisp bread made from rye and yeast. Most soft breads were moderate folate sources, even though they were baked with wholemeal flours.