Food matrix structure (from biscuit to custard) impacts on folate bioavailability in healthy volunteers

IntroductionBecause folate deficiency has been associated with an increased risk of development of neural tubedefect, depression… folate fortification is recommended for populations at risk (pregnant, frail population),including supplementation within food-matrix. However, this hydrosoluble vitamin is knownto interact with food matrix components. This could ultimately impact on bioavailability of folates inplasma.ObjectiveThe aim of the present work is to measure folate plasma levels of volunteers following ingestion ofdifferent matrices (Custard, pudding, sponge cake and biscuit) similar in terms of macronutrientsand overall folate content but different in texture and potentially digestibility rate.MethodologyTwelve healthy young volunteers were offered the matrices according to a randomized, controlledcross over design. Plasma folate concentrations were determined before and up to 8 hours postmatrix ingestion. Results for folate overall bioavailability (corrected for ingested folate) correspondto area under the curve (AUC) and expressed in arbitrary units (UA).Main findingsFolate bioavailability over the entire post prandial period was significantly (P<0.05) superior for puddingand sponge cake (4.81±0.23 and 4.62±0.26 AU respectively) compared to custard (3.81±1.0AU) whereas biscuit was intermediary (4.34±0.29 AU). The kinetics of evolution of folate levels inplasma were different between matrices with a maximum folate concentration significantly (P<0.05)delayed for biscuit (220 min) vs other matrices.ConclusionAlthough macronutrients and folate content were similar between the four matrices tested, overallbioavailability (AUC) and plasma appearance rate of folates were conditioned by food structure.In Custard, overall folate released in plasma was significantly reduced whereas the folate plasmapost prandial peak was delayed with biscuit. An altered and/or delayed dissolution of folates in thealimentary bolus depending on the matrix structure in the mouth then the gut is hypothesized and iscurrently ...