International inter-laboratory analyses of food folate

The determination of folic acid in milk and paediatric formulae by optical biosensor assay utilising folate binding protein

“…These analytical techniques for the determination of folate in foods, together with conventional and continuous-flow biospecific protein-binding and immunoassay strategies, have been reviewed recently (Arcot & Shrestha, 2005;Ball, 2006;Eitenmiller & Landen, 1999). The many complexities involved in measurement of the folate content of food have been emphasised recently by the poor agreement between methods and between laboratories, as determined under controlled interlaboratory conditions (Koontz et al, 2005;Puwastien, Pinprapai, Judprasong, & Tamura, 2005).…”

An optical biosensor assay for the determination of folate in milk and nutritional dairy products

“…These generic procedures are intended to release bound folates, and to convert endogenous polyglutamate vitamers to the mono-or di-glutamate forms for analytical detection. To date, such procedures are not internationally harmonised and numerous variants have been described, a factor contributing to the diversity of data reported for foods by any analytical platform, since measured folate content is highly dependent on matrix, buffer, pH, antioxidant concentration, temperature, and both enzyme selection and sequence during multi-enzyme strategies (Arcot & Shrestha, 2005;Ball, 2006;Eitenmiller & Landen, 1999;Koontz et al, 2005;Puwastien et al, 2005;Quinlivan et al, 2006).…”

“…Despite the plethora of analytical strategies available for measurement of the folate content in foods, the many procedural complexities continue to result in poor agreement between methods and between laboratories (Koontz et al, 2005;Puwastien, Pinprapai, Judprasong, & Tamura, 2005). Evolving analytical developments and the implementation of the dietary folate equivalent (DFE) concept make the reliable assessment of dietary folate intake within populations challenging (Tamura & Picciano, 2006).…”

Analytical Methods to Assess the Bioavailability of Water‐Soluble Vitamins in Food–Exemplified by Folate

“…However, today there is still no " golden " standard method available for folate quantifi cation and determination. Thorough quality control and documentation are required during all steps of sample preparation and analysis [48,49] .…”