Mass spectrometry-based analytical developments to link iron speciation to iron bioavailability in maize

Area of Science:

• Agricultural Science
• Analytical Chemistry
• Biochemistry

Background:

• Iron bioavailability in maize is crucial for human nutrition.
• Understanding molecular iron distribution is key to improving maize iron content.
• Previous studies lacked detailed molecular insights into iron distribution in maize.

Purpose of the Study:

• To develop a sequential fractionation method for analyzing iron molecular distribution in maize.
• To determine iron bioavailability in maize using an in-vitro gastro-intestinal digestion model.
• To apply these methods to differentiate maize varieties based on iron bioavailability.

Main Methods:

• Sequential extraction (water, hexane, saccharification, proteolysis).
• In-vitro simulated gastro-intestinal digestion model for bioavailability assessment.
• Coupling of hydrophilic interaction chromatography (HILIC) and size exclusion chromatography (SEC) with inductively coupled plasma mass spectrometry (ICP-MS) and high resolution electrospray mass spectrometry (HR-ESI-MS).

Main Results:

• First data on molecular distribution of iron in maize.
• Identification of water-soluble Fe(III)-mugineate, Fe(III)-(citrate)2, and Fe(III)2-(phytate)2.
• Successful discrimination between low and high iron bioavailable maize seeds.

Conclusions:

• The developed analytical approach provides comprehensive insights into iron molecular distribution and bioavailability in maize.
• This method can be used to identify and select maize varieties with enhanced iron bioavailability.
• The findings contribute to efforts in improving the nutritional value of maize through breeding and agricultural practices.