Rapid Analysis of Sugars Using Discrete Analyzers

Significance of the Topic

Rapid, reliable quantification of simple sugars (glucose, fructose, sucrose and lactose) is central in food and beverage quality control, fermentation monitoring and raw-material inspection. Automated discrete photometric analyzers enable high-throughput, low-cost enzymatic assays with minimal operator intervention, supporting regulatory compliance and process control in wineries, juice producers and fermentation-based industries.

Objectives and Study Overview

This poster reports performance characteristics of enzymatic sugar assays implemented on Thermo Scientific discrete analyzers (Gallery and Arena platforms). The goals were to demonstrate method linearity, precision, measurement range, throughput and agreement with reference techniques (HPLC and FTIR) for individual sugars and combinations (glucose, fructose, glucose+fructose, glucose+fructose+sucrose, sucrose as total glucose and lactose as glucose). The work evaluates ready-to-use reagents, automated calibration/dilution features and suitability for routine laboratory workflows.

Methodology

Analytical approach and routine conditions used in the study are summarized below:

• Enzymatic photometric assays run at 37 °C; endpoint or kinetic reading of NAD(P)H formation at 340 nm with a 600 nm side wavelength for verification.
• Automated sample handling with sample and reagent over-dispense/discard to prevent carryover and contamination.
• Standardized pre-dilution of 1:50 typically used to reduce matrix effects; instruments perform automated pre- and post-dilutions to cover wide measuring ranges.
• Ready-to-use reagent vials (bar-coded) optimized volumes, each kit supporting up to ~350 tests; reagents tracked for lot, expiration, on-board stability and linked calibrations.
• Automated calibrator dilution and optional insertion of extra calibration points when required; calculations for combined assays (e.g., sucrose or lactose determination requiring a separate glucose measurement) are implemented on-board.

Instrumention Used

• Thermo Scientific Gallery and Gallery Plus discrete photometric analyzers (Arena mentioned as compatible platform).
• Ready-to-use Thermo Scientific enzymatic reagent kits for D-Glucose, D-Fructose, Glucose+Fructose, Glucose+Fructose+Sucrose, Sucrose (Total Glucose) and Lactose (Glucose).
• Optical detection at 340 nm with 600 nm side wavelength; temperature control to maintain 37 °C.

Measurement Ranges and Throughput

Key analytical ranges delivered by the reagent kits (reported as approximate limits):

• D-Glucose: ~0.1 to 160 g/L
• D-Fructose: ~0.7 to 200 g/L
• D-Glucose + D-Fructose: ~0.4 to 200 g/L
• D-Glucose + D-Fructose + Sucrose: ~0.24 to 200 g/L
• Sucrose (reported as Total Glucose): ~0.1 to 100 g/L
• Lactose (reported as Glucose): ~0.05 to 15 g/L

Instrument throughput depends on model: Gallery ≈ 200 photometric tests/hour; Gallery Plus ≈ 350 photometric tests/hour. Example: Gallery Plus can perform ~77 combined (glucose+fructose+sucrose) tests per hour with first results in under 20 minutes.

Main Results and Discussion

• Method comparison: Discrete analyzer results were compared to HPLC (and for glucose/fructose also to FTIR) across a broad set of sample types (dry to sweet wines, liqueurs, juices and fermentation samples). Correlation coefficients (r2) for concentration comparisons were ≥ 0.984, commonly >0.99, indicating excellent agreement with reference methods.
• Linearity: Linear calibration fits were used; automated calibrator dilution enabled extended linear ranges and additional calibration points when needed. Linearity plots (including lactose) showed close agreement between theoretical and measured values.
• Precision: Within-run coefficients of variation (CV) were typically ~1% and improved at higher concentrations; total precision generally <2%. Within-run CVs as low as 0.5% were reported for D-glucose at certain levels.
• Speed and automation: The discrete-cell architecture allows multiple assays on a single sample without manual method changeover, reducing walk-away time and increasing laboratory efficiency. Minimal sample pretreatment is required for most homogeneous liquid matrices.
• Reagent handling: Bar-coded, ready-to-use reagent vials with on-board stability and instrument prompts for low reagent levels reduced user error and operator time; volume-optimized kits improved cost-efficiency.

Benefits and Practical Applications

• High-throughput routine testing for food and beverage QC, fermentation monitoring and raw-material inspection with fast time-to-result and low operator involvement.
• Robust analytical performance (linearity, precision and accuracy) comparable to HPLC and FTIR for a wide concentration range and diverse matrices.
• Scalability and flexibility through automated dilution and multi-reagent assay capability, enabling complex assays (e.g., glucose+fructose+sucrose) to be run automatically.
• Reduced reagent handling errors and inventory management burden due to ready-to-use, bar-coded kits with automated calibration linkage.

Limitations and Considerations

• Some assays (sucrose as total glucose, lactose as glucose) require an additional glucose measurement and calculation; care must be taken in result interpretation when matrix interferences occur.
• Reported performance primarily applies to homogeneous liquid samples; heavily particulate or viscous samples may need pretreatment.
• Analytical ranges, while broad due to automated dilution, have upper and lower limits that require appropriate sample dilution to remain within validated ranges.

Future Trends and Potential Applications

• Integration with laboratory information management systems (LIMS) and direct process control loops for real-time fermentation monitoring and automated QC decision-making.
• Expansion of discrete analyzer assays to additional carbohydrates and related metabolites, and development of multiplexed reagent chemistries to reduce per-sample cost further.
• Miniaturization and greener reagent formulations to lower waste, decrease reagent consumption and improve sustainability in high-throughput labs.
• Enhanced on-board QC, remote monitoring and cloud-based reagent/lot tracking to further reduce manual oversight and improve traceability.

Conclusion

The Thermo Scientific discrete enzymatic assays evaluated provide accurate, precise and high-throughput quantification of glucose, fructose, sucrose (as total glucose) and lactose (as glucose). Automated reagent handling, calibration and dilution features deliver broad linear ranges and strong agreement with HPLC and FTIR reference methods. The combination of fast time-to-result, low reagent volumes and minimal operator input makes these systems well suited for routine food, beverage and fermentation laboratories seeking reliable sugar analysis with efficient workflow integration.

References

1. Bergmeyer, H.U. Methods of Enzymatic Analysis. Verlag Chemie / Academic Press, Inc., New York, NY, 1974.
2. Jacobson, J.L. Introduction to Wine Laboratory Practices and Procedures. Springer Science and Business Media, Inc., New York, NY, 2006.
3. International Organisation of Vine and Wine. Compendium of International Methods of Analysis, Reducing substances, Method OIV-MA-AS311-01A, Paris, France.
4. Association of Official Analytical Chemists (AOAC). Official Methods of Analysis: Glucose and Fructose in wine, AOAC Method 985.09 (enzymatic), Rockville, MD.