Elemental fingerprinting of mineral species in iron‐fortified milk: anomalous small‐angle X‐ray scattering and resonant soft X‐ray scattering studies. (27th June 2018)

• Record Type: Journal Article
• Authors: Ingham, Bridget; Kirby, Nigel; Wang, Cheng; Brady, Mike; Carr, Alistair
• Is Part Of: Journal of synchrotron radiation. Volume 25:Part 4(2018)
• Page Start: 1106
• Page End: 1112
• Publication Date: 2018-06-27
• Subjects: anomalous small‐angle X‐ray scattering -- resonant soft X‐ray scattering -- milk -- iron fortification; Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577518007774
• Languages: English
• ISSNs: 0909-0495

Abstract

Abstract : The advantages, challenges and limitations of two complementary techniques – resonant soft X‐ray scattering and anomalous small‐angle X‐ray scattering – are presented, using iron‐fortified milk as an example. Abstract : Anomalous small‐angle X‐ray scattering (ASAXS) and resonant soft X‐ray scattering (RSoXS) are two related techniques that can enable element‐specific structural information to be obtained. The development of iron‐fortified milk products can greatly benefit from such techniques, allowing the structure of iron and other minerals (such as native calcium) within the casein micelle to be determined. Each method has advantages and disadvantages: for ASAXS, the sample preparation is straightforward, but the signal is relatively low and information about the structure of Ca is difficult to access. RSoXS can be used to study both Ca and Fe, and the element‐specific signals observed are proportionally much higher; however, the measurements are challenging due to the difficulty of precise control of the solution thickness using currently available vacuum‐compatible liquid cells. Nevertheless, complementary results from both techniques indicate Fe is co‐located with Ca, i.e. within the colloidal calcium phosphate nanoclusters that are present within native casein micelles in milk.