FAMEs In Peanut Butter by GC/FID Using Zebron™ ZB-FAME

Significance of the Topic

Profiling of fatty acid methyl esters (FAMEs) in peanut butter is essential for accurate nutritional labeling, quality control and regulatory compliance. Rapid and reliable analysis of cis/trans isomers supports food safety and product consistency in both research and industrial laboratories.

Objectives and Study Overview

This study aims to demonstrate a fast, robust gas chromatographic method for separation and quantification of twelve key fatty acids in peanut butter. Employing a short Zebron ZB-FAME column with flame ionization detection (FID), the method targets high resolution, particularly for C18:1 cis/trans isomers, within a 25-minute run time.

Methodology

The sample preparation protocol consists of:

• Weighing 100–200 mg peanut butter and adding 100 mg pyrogallic acid
• Adding 2 mL ethanol and 10 mL 8.3 M HCl, then heating at 70 °C for 45 min for acid-catalyzed transmethylation
• Extracting fatty acids with 2 mL diethyl ether and 2 mL chloroform, followed by solvent evaporation
• Derivatizing residues in 1 mL toluene and 2 mL 8 % boron trifluoride in methanol at 100 °C for 45 min
• Adding 5 mL water, 1 mL hexane and 1 g Na2SO4, then extracting the hexane layer for GC analysis

Použitá instrumentace

The chromatographic system is configured as follows:

• Column: Zebron ZB-FAME, 30 m × 0.25 mm ID, 0.20 µm film
• Injection: Split 50:1, 1 µL sample, inlet temperature 240 °C, single taper wool liner
• Carrier gas: Helium at 1.2 mL/min (constant flow)
• Oven program: 100 °C hold 2 min; ramp to 140 °C at 10 °C/min; to 190 °C at 3 °C/min; to 260 °C at 30 °C/min, hold 2 min
• Detector: FID at 260 °C

Main Results and Discussion

The method achieves baseline separation of twelve FAMEs, including trans and cis C18:1 isomers, in under 25 minutes without compromising peak shape. The fast temperature program and column selectivity enable clear resolution of essential fatty acids (C11:0 to C24:0), demonstrating reproducible retention times and consistent peak areas suitable for quantitative analysis.

Benefits and Practical Applications

This protocol offers:

• High throughput analysis for routine nutritional and quality control testing
• Robust cis/trans isomer resolution critical for regulatory compliance
• Compatibility with existing Agilent® and Thermo Scientific® GC systems

Future Trends and Potential Applications

Advancements may include coupling to mass spectrometry for structural confirmation, further miniaturization of sample preparation, automation of derivatization steps, and integration into continuous monitoring systems for on-line quality control in food processing industries.

Conclusion

The presented GC/FID method using the Zebron ZB-FAME column provides a rapid, reliable, and high-resolution approach for FAME profiling in peanut butter. Its efficiency and performance make it a valuable tool for laboratories focused on food analysis and quality assurance.