Chromatography for Foods and Beverages - Carbohydrates Analysis Applications Notebook

Significance of the Topic

Carbohydrates are fundamental components of foods and beverages, directly influencing taste, nutrition, energy value, and technological properties. Precise determination of sugars, oligo- and polysaccharides, and related derivatives such as inulins and sialic acids is critical for nutritional labeling, quality control, authenticity testing, and process optimization across the food and beverage industry.

Objectives and Study Overview

This compendium reviews state-of-the-art chromatographic techniques and associated detection methods applied to the analysis of carbohydrates in diverse matrices, including corn syrup, dietary fibers, milk and dairy products, maltodextrins, infant formulas, beverages, honey, and coffee. The goal is to present validated workflows that maximize selectivity, sensitivity, throughput, and operational simplicity.

Methodology and Instrumentation

The analytical approaches encompass:

• Reversed-phase and hydrophilic interaction liquid chromatography (HILIC) using UHPLC systems (UltiMate™ 3000 UHPLC+).
• High-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) on CarboPac™ columns.
• Charged aerosol detection (CAD) for nonvolatile carbohydrates and high molecular weight saccharides.
• Refractive index (RI) detection for neutral sugars.
• Electrochemical detection modes (amperometric, coulometric array) for selective profiling.
• Diode array and fluorescence detection for derivatized and native sugars.
• Ion chromatography (IC) and reagent-free IC (RFIC) systems for ionic species.
• Integrated IC-MS and LC-MS solutions for structural confirmation using the MSQ™ Plus single quadrupole.
• Chromeleon™ Chromatography Data System for unified control, data processing, and compliance.
• Automated sample preparation via Accelerated Solvent Extraction (ASE) and solid-phase extraction (AutoTrace™).
• On-line process analyzers for real-time monitoring of production streams.

Main Results and Discussion

Representative applications demonstrate:

• Baseline separation and quantitation of fructose, glucose, sucrose, and maltose in beverages and sodas by HPLC-CAD and HPAE-PAD, with limits of detection in the low milligram per liter range.
• Characterization of inulin oligosaccharide profiles from chicory and dahlia sources using gradient HPAE-PAD, distinguishing chain-length distributions relevant to dietary fiber functionality.
• Fast, robust analysis of lactose and lactulose in milk, yogurt, and cheese by HPLC-CAD and HPAE-PAD, enabling compliance with lactose-free product requirements and heat-treatment markers.
• Separation of maltodextrins of varying degree of hydrolysis (M040–M200) with CAD on HILIC and size-exclusion columns, supporting formulation and quality assessment in brewing and food industries.
• Determination of sialic acid isomers in infant formulas by HPAE-PAD and UHPLC-fluorescence after derivatization, ensuring proper enrichment to mimic human milk oligosaccharides.
• Analysis of mono- and disaccharides in coffee and juices using fast IC methods conforming to AOAC protocols, reducing run times by up to tenfold.

Benefits and Practical Applications

• Universal detection capability for nonchromophoric carbohydrates without derivatization via CAD and PAD.
• Wide dynamic range and excellent reproducibility for trace to bulk analytes.
• Automated eluent generation and suppression in RFIC reduce consumable handling and error.
• Single-software control streamlines multi-detector, multi-technique laboratories.
• High-throughput workflows and miniaturized formats enable small sample volumes and faster turnaround.

Future Trends and Potential Uses

Emerging directions include real-time in-line monitoring of fermentation and enzymatic processes, expanded coupling of carbohydrate separations with high-resolution mass spectrometry for structural glycomics, advanced chemometric fingerprinting for authentication, and integration of microfluidic platforms for point-of-use testing in quality control and food safety.

Conclusion

A comprehensive suite of chromatographic and detection techniques provides robust, sensitive, and flexible solutions for carbohydrate analysis across food and beverage applications. Continuous advances in instrumentation, data systems, and automation will further enhance analytical performance and process efficiency.

References

• Application Note 67: Determination of Plant-Derived Natural Oligo- and Polysaccharides.
• Application Update 150: Neutral Oligo- and Polysaccharides Using CarboPac PA200.
• Application Note 155: Trans-Galactooligosaccharides by HPAE-PAD (AOAC 2001.02).
• Application Note 182: Measuring Lactose in Milk by HPLC-CAD.
• Application Note 248: Lactose in Lactose-Free Milk Products by HPAE-PAD.
• Application Note 253: Infant Formula Sialic Acids by HPAE-PAD.
• Application Note 266: Sialic Acids by UHPLC-Fluorescence.
• Application Note 280: Carbohydrates in Coffee: Fast IC Method vs. AOAC 995.13.