Determination of Food Sugars in Fruit Juice Using Evaporative Light Scattering Detection and BEH Amide Column Chemistry

Significance of the Topic

The accurate analysis of simple sugars in fruit juices is critical for quality control, nutritional labeling, and compliance with regulatory standards. Profiling sugars such as fructose, glucose, sucrose, maltose, and sugar alcohols informs cultivar authentication and detects potential adulteration, ensuring product integrity in the beverage industry.

Objectives and Overview

This study aimed to develop a rapid, cost-effective method for quantifying five key sugars in diverse fruit juices with minimal sample preparation. Utilizing Waters XBridge BEH Amide XP column chemistry and evaporative light scattering detection (ELSD) on an Alliance HPLC System, the method addresses challenges associated with non-chromophoric analytes and column longevity.

Methodology and Instrumentation

• Sample Preparation: Fruit juices were centrifuged to remove particulates, then diluted 1:50 (water/acetone) prior to analysis.
• Column Chemistry: XBridge BEH Amide XP column (4.6×100 mm, 2.5 µm) to minimize Schiff base formation and extend column life.
• HPLC Conditions: Binary gradient with water and acetone modified with triethylamine; gradient elution enabled separation of monosaccharides, disaccharides, sugar alcohols, and oligomers.
• Detection: 2424 Evaporative Light Scattering Detector (ELSD) for response to non-UV-active compounds.
• Calibration: Six-point calibration curves constructed from serial dilutions of a standard sugar mixture.

Main Results and Discussion

The optimized method achieved baseline resolution of five analytes within 7.5 minutes. Chromatograms demonstrated distinct peaks for fructose, glucose, sucrose, maltose, and sorbitol. Quantitative analysis of various juices revealed typical sugar concentrations: pineapple juice (fructose 7.82 g/100 mL, glucose 7.46 g/100 mL, sucrose 3.66 g/100 mL), white grape juice, apple juice (detectable sorbitol at 0.45 g/100 mL indicating cultivar traits), and orange juice profiles. ELSD gradient capability enabled detection of co-eluting and non-chromophoric compounds.

Benefits and Practical Applications

• Minimal Sample Preparation: Simple centrifugation and dilution reduces labor and time.
• Rapid Analysis: Less than 7.5 minutes per run enhances throughput.
• Robustness: Amide column chemistry resists Schiff base degradation, extending column life.
• Applicability: Suitable for routine quality control, cultivar verification, nutritional labeling, and adulteration detection in the beverage industry.

Future Trends and Potential Applications

Emerging trends include coupling amide-based HPLC separations with mass spectrometry for enhanced sensitivity, development of ultra-high-throughput platforms for large-scale screening, and adaptation of similar methods to other food matrices such as dairy or plant extracts. Advances in detector technology may further improve limits of detection for low-abundance carbohydrates.

Conclusion

The combination of XBridge BEH Amide XP column chemistry and ELSD on a robust HPLC platform delivers a fast, accurate, and reliable method for profiling key sugars in fruit juices. This approach supports quality assurance, regulatory compliance, and authenticity testing with minimal operational complexity.

Used Instrumentation

• Waters Alliance HPLC System
• 2424 Evaporative Light Scattering Detector
• XBridge BEH Amide XP Column (4.6×100 mm, 2.5 µm)

References

• Benvenuti M.E., Burgess J. Determination of Food Sugars in Fruit Juice Using Evaporative Light Scattering Detection and BEH Amide Column Chemistry. Waters Corporation Application Note; 2012.