Determination of Free Amino Acids Content in Alcoholic and Non-Alcoholic Beverages Using the AccQ•Tag Ultra Derivatization Kit

Significance of the Topic

The profile of free amino acids in beverages influences taste and flavor, critical for product quality and consumer acceptance. Rapid and accurate analysis supports quality control and research in fermented and non-fermented drinks.

Objectives and Study Overview

This study demonstrates a fast, ten-minute UPLC method using the AccQ•Tag Ultra Derivatization Kit to quantify free amino acids in various alcoholic and non-alcoholic beverages. Key aims:

• Develop a streamlined workflow combining derivatization, separation, and detection.
• Test method performance on samples including wine, cider, kombucha, soft drinks, and sports nutrition powders.
• Provide optimized dilution guidelines for different beverage matrices.

Methodology

Samples were derivatized with the AccQ•Tag Ultra Kit, using norvaline as an internal standard in borate buffer. A calibration curve covering 21 amino acids (0.5–500 μM) was established. Liquid samples were diluted (undiluted to 1:100) to fit the calibration range. A minor protocol adjustment included a 10-s centrifugation step after derivatization to remove condensation.

Instrumentation Used

• ACQUITY UPLC H-Class PLUS System
• ACQUITY UPLC PDA Detector (260 nm)
• Empower 3 Chromatography Data System
• Waters Total Recovery Vials

Main Results and Discussion

Calibration curves showed excellent linearity (R2 = 0.984–0.9999). Technical replicates yielded <5% relative standard deviation. A characteristic unknown peak in apple-based drinks was identified as asparagine by comparing derivatization profiles in different solvents. Quantified taurine in an energy drink matched the label claim (0.44 vs. 0.40 g/100 mL). Chromatograms of undiluted samples revealed clear separation of 21 amino acids within ten minutes.

Benefits and Practical Applications

• Rapid method setup with complete workflow (standards, reagents, columns, software).
• Short analysis time (ten-minute gradient) increases throughput.
• Flexible UPLC system use versus dedicated amino acid analyzers.
• Minimal sample preparation and robust performance for routine quality control.

Future Trends and Opportunities

Advances may include integration with mass spectrometry for enhanced specificity, further miniaturization of derivatization protocols, and expansion to other complex matrices. Automated sample prep and data processing could streamline high-throughput screening in food and beverage industries.

Conclusion

The AccQ•Tag Ultra derivatization coupled with UPLC-PDA provides a sensitive, reproducible, and fast solution for free amino acid analysis in diverse beverages. The method’s simplicity and flexibility make it an attractive tool for both research and quality control laboratories.

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