AOAC SPIFAN Stakeholder Panel Meeting Book (March 12, 2020)

Forms of Inositol Found in Foods

Myo-inositol occurs in foods as: Free myo-inositol ( only form of 9 cyclohexanehexols with known biological importance )

Phytic acid & inositol phosphates ( Plants store P as phytic acid, human GI may utilise. Many IPn in mammalian cells, with physiological functions )

Inositol-phospholipids (Phosphatidylinositol, the primary myo-inositol containing PL in animal tissues)

Analytical question-What to measure? • Since IF (bovine-, caprine-, or soy-based) can contain myo -inositol in multiple forms, Codex needs to define what is to be analytically measured for compliance purposes. • So, what forms of myo-inositol need to be measured? • Free myo-inositol estimation is relatively simple. • The inclusion of all phosphorylated forms (PI’s and IP’s) of myo-inositol within a measurement is a challenge if the release of all bound forms is to be accomplished routinely. • Soy-based formulas will provide additional problems due to phytate. • The AOAC SPIFAN Inositol working group has defined inositol as free myo- inositol (CAS 87-89-8) and phosphatidylinositol, but excluding methyl ethers, glycosides, phosphorylated forms, and phytate.