A Comparison of Amino Acid Profiles of Plant-Based Alternative Proteins and Meat Products

Significance of the Topic

To address the growing global demand for sustainable protein sources and meet nutritional requirements, plant-based alternatives are gaining prominence. Comparing their amino acid profiles with traditional meat products is crucial for product development, nutritional evaluation, and quality control in the food industry.

Objectives and Study Overview

This study aimed to develop and validate an HPLC-based method for the simultaneous determination of 24 amino acids—including taurine, theanine, glucosamine, cysteine, and cystine—in plant-based nuggets, chicken nuggets, and chicken breast meat following acidic hydrolysis. The goal was to compare their amino acid compositions and assess method performance.

Used Instrumentation

• Agilent 1260 Infinity II Liquid Chromatograph (binary pump, multisampler, multicolumn thermostat)
• Agilent 1260 Infinity II Diode Array Detector (DAD)
• Agilent 1260 Infinity II Fluorescence Detector (FLD)
• Agilent AdvanceBio AAA column (3.0×100 mm, 2.7 µm) with matching guard column
• Agilent Captiva Premium 0.2 µm RC syringe filters for sample cleanup

Methodology

Samples were homogenized and hydrolyzed in 6 N HCl at 110 °C for 24 hours. After cooling and centrifugation, extracts were filtered and diluted 100×. Pre-column derivatization with o-phthalaldehyde (OPA) for primary amino acids and FMOC for secondary amino acids was automated in the autosampler. A gradient elution with phosphate-borate buffer (pH 8.2) and a water/methanol/acetonitrile mixture was applied at 0.6 mL/min and 40 °C. The FLD detected all amino acids except cysteine and cystine, for which DAD data were used.

Main Results and Discussion

The method achieved baseline separation of 24 amino acids plus two internal standards within 24 minutes. Limits of quantification were 0.90 pmol/µL (4.5 pmol/µL for cysteine) with R² > 0.999 and retention time and area precision below 1%. Recovery in nugget matrices ranged from 90 % to 130 %. Quantitative profiling revealed that chicken breast meat contained the highest total amino acid content, while plant-based and chicken nuggets had comparable essential amino acid levels. Plant-based nuggets exhibited higher glutamic acid and cysteine than chicken nuggets, whereas glucosamine was lower.

Benefits and Practical Applications

• Automated derivatization reduces manual handling and error.
• Dual-mode detection (FLD and DAD) ensures comprehensive quantification.
• Robust cleanup with Captiva filters minimizes matrix interference.
• Applicable for routine quality control of plant-based and meat products.

Future Trends and Potential Applications

Expanding target analytes to include non-proteogenic amino acids, integrating mass spectrometric detection for structural confirmation, and developing high-throughput workflows will further enhance nutritional profiling of novel protein sources and support the optimization of alternative food products.

Conclusion

A reliable, sensitive, and fully automated LC-based method was established for comparing amino acid profiles in plant-based nuggets, chicken nuggets, and chicken breast. The approach facilitates accurate nutritional assessment and supports the development and quality control of alternative protein formulations.

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