Folate composition of 10 types of mushrooms determined by liquid chromatography-mass spectrometry

White button, crimini, shiitake, maitake. enoki, oyster, chanterelle, morel, portabella, and uv-treated portabella mushrooms were sampled from U.S. retail outlets and major producers. Folate [5-methyltetrahydrofolate (5-CH3-H(4)folate), 10-formyl folate (10-HCO-folate), 5-formyltetrahydrofolate (5-HCO-H(4)folate)] was analysed using a validated LC-MS method in four composites of each product, including an in-house mushroom control composite and a reference material (BCR 485 Lyophilised Mixed Vegetables). Chanterelle and morel had the lowest total folate (2-6 mu g/100 g), oyster had the highest (mean, 44.2 mu g/100 g); other types contained 12.4 mu g/100 g (shiitake) to 29.8 mu g/100 g (vitamin D-enhanced portabella). Enoki and oyster had almost exclusively 5-CH3-H(4)folate. Morel and chanterelle contained predominately formyl folates. Other species had similar amounts of 5-CH3-H(4)folate and formyl folates. Enoki, oyster, and shiitake, unlike all others, had low to non-detectable 10-HCO-folate (<1 mu g/100 g). These precise data on the composition of folate vitamers in different types of mushrooms will facilitate assessment of the dietary contribution of naturally occurring folate. (C) 2011 Elsevier Ltd. All rights reserved.