Quantitative Detection of Pyrazines in Edible Oils Using SABRE Hyperpolarized NMR Spectroscopy

Area of Science:

• Analytical Chemistry
• Food Science
• Nuclear Magnetic Resonance Spectroscopy

Background:

• Pyrazines are crucial flavor compounds in food, vital for quality and authenticity assessment.
• Complex food matrices necessitate extensive pretreatment for pyrazine detection due to interfering compounds.
• Current methods often lack the selectivity and sensitivity required for accurate trace analysis in food.

Purpose of the Study:

• To develop a highly selective and sensitive method for detecting pyrazines in food matrices.
• To utilize hyperpolarized Nuclear Magnetic Resonance (NMR) spectroscopy for quantitative pyrazine analysis.
• To validate the Signal Amplification By Reversible Exchange (SABRE) technique for food quality assessment.

Main Methods:

• Employed Signal Amplification By Reversible Exchange (SABRE) hyperpolarization on a benchtop NMR system (60 MHz, 1.4 T).
• Utilized a cosubstrate strategy for enhanced hyperpolarization of pyrazine compounds.
• Implemented a simplified extraction procedure for sample preparation, minimizing matrix interference.

Main Results:

• Achieved accurate quantification of pyrazine in sesame oil at a concentration of 59.3 μmol/L.
• Established a low limit of quantification for pyrazines at 21.0 μmol/L.
• Demonstrated high sensitivity and accuracy comparable to conventional high-field NMR (500 MHz, 11.7 T) on a low-field instrument.

Conclusions:

• Signal Amplification By Reversible Exchange (SABRE) hyperpolarization offers a powerful tool for selective trace analysis of pyrazines.
• The developed method simplifies sample preparation, making it suitable for routine food analysis.
• This approach has significant potential for food quality control, flavor profiling, and bioactivity studies.