Particle Size, Surface Area, and Amorphous Content as Predictors of Solubility and Bioavailability for Five Commercial Sources of Ferric Orthophosphate in Ready-To-Eat Cereal

Abstract

Ferric orthophosphate (FePO4) has had limited use as an iron fortificant in ready-to-eat (RTE) cereal because of its variable bioavailability, the mechanism of which is poorly understood. Even though FePO4 has desirable sensory properties as compared to other affordable iron fortificants, few published studies have well-characterized its physicochemical properties. Semi-crystalline materials such as FePO4 have varying degrees of molecular disorder, referred to as amorphous content, which is hypothesized to be an important factor in bioavailability. The objective of this study was to systematically measure the physicochemical factors of particle size, surface area, amorphous content, and solubility underlying the variation in FePO4 bioavailability. Five commercial FePO4 sources and ferrous sulfate were added to individual batches of RTE cereal. The relative bioavailability value (RBV) of each iron source, determined using the AOAC Rat Hemoglobin Repletion Bioassay, ranged from 51% to 99% (p < 0.05), which is higher than typically reported. Solubility in dilute HCl accurately predicted RBV (R2 = 0.93, p = 0.008). Amorphous content measured by Dynamic Vapor Sorption ranged from 1.7% to 23.8% and was a better determinant of solubility (R2 = 0.91; p = 0.0002) than surface area (R2 = 0.83; p = 0.002) and median particle size (R2 = 0.59; p = 0.12). The results indicate that while solubility of FePO4 is highly predictive of RBV, solubility, in turn, is strongly linked to amorphous content and surface area. This information may prove useful for the production of FePO4 with the desired RBV.

The Potential Cytotoxic Activity Enhancement of α-Mangostin in Chitosan-Kappa Carrageenan-Loaded Nanoparticle against MCF-7 Cell Line

“…The αM-Ch/Cr nanoparticles showed a 4-fold increase in the solubility value, likely due to the contribution of hydrophilic polymers used in the formula and also the nature of nanoparticles, which tend to increase the total surface area of the substance in contact with the solvent medium, resulting in a significant increase in solubility [ 47 , 48 , 49 ].…”

Dissolution and storage stability of nanostructured calcium carbonates and phosphates for nutrition

“…FSP-made Fe/Zn phosphate nanopowders with amorphous structure showed no influence of SSA (86-143 m 2 /g) on Fe dissolution (Hilty et al 2009). Crystallinity is a determinant of dissolution of FePO 4 (Willis and Allen 1999), and amorphous content of FePO 4 was a better predictor of solubility and bioavailability than SSA (Dickmann et al 2016). At the end of our experiments, perhaps the S1 nanopowders were at (or close to) their solubility limit, causing powder dissolution to slow down (Margolis and Moreno 1992) and resulting in comparable dissolved Ca values.…”

Efecto del diámetro de partícula en las propiedades funcionales del polvo de peciolo de brócoli (Brassica oleracea L.)

“…Se encontró el efecto del diámetro de partícula (p<0,05) en la CS, el rango encontrado fue de 3,39 a 8,68% siendo de mayor solubilidad a menor diámetro de partícula, comportamiento similar encontraron Daou & Zhang, (2012) para salvado de arroz de 8,31% y estas disminuyeron a mayor diámetro de partícula (Daou & Zhang, 2012y Serna-Cock et al, 2015, podría relacionarse con mayor velocidad de disociación y un posible contenido de fibra dietaría insoluble (Serna-Cock, et al, 2015), esta propiedad está relacionado con el área superficial de la partícula (Dickmann et al, 2016); la microestructras, superficie amorfa o cristalina (Shea et al, 2012).…”