A rapid and reliable method for discriminating rice products from different regions using MCX-based solid-phase...

Area of Science:

• Food Science
• Analytical Chemistry
• Metabolomics

Background:

• Global rice trade expansion necessitates robust authenticity control.
• Existing methods for geographical origin discrimination lack high-throughput capabilities.
• Accurate rice origin verification is crucial for consumer trust and regulatory compliance.

Purpose of the Study:

• To develop a rapid, high-throughput analytical method for distinguishing the geographical origin of white rice.
• To optimize sample preparation and mass spectrometry conditions for effective rice discrimination.
• To identify key metabolites indicative of rice geographical origin.

Main Methods:

• Development of a direct infusion-mass spectrometry (DI-MS) approach.
• Optimization of sample cleanup using polytetrafluoroethylene (PTFE) filters and mixed-mode cation exchange (MCX) solid-phase extraction (SPE) with varying methanol concentrations.
• Application of chemometric methods, including partial least squares discriminant analysis (PLS-DA) and random forests, for data analysis.
• Utilized DI-MS in positive ion mode and targeted DI-MS/MS.

Main Results:

• Achieved excellent discriminatory ability using MCX SPE with 100% methanol and DI-MS (accuracy=1.000, Q²=0.720) or MCX SPE with 20% methanol and DI-MS/MS (accuracy=1.000, Q²=0.849).
• Identified differentially expressed metabolites, including lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylglycerol classes.
• The developed method demonstrated high accuracy and reliability in geographical discrimination.

Conclusions:

• The study presents a rapid and reliable platform for the geographical discrimination of white rice using DI-MS.
• This method offers a valuable tool for enhancing the authenticity control of rice products in the global market.
• The findings contribute to safeguarding the integrity of the rice supply chain.