Determination of Moisture in Cheese

Importance of the Topic

Raw cheese moisture influences quality attributes such as texture, taste, and microbial stability. Accurate moisture content determination is essential for regulatory compliance, yield calculation, and dry-basis constituent analyses in dairy production.

Objectives and Study Overview

This application note demonstrates the use of the LECO TGM800 thermogravimetric analyzer to measure moisture in various cheese types. The study compares fixed drying time methods with different crucible geometries and a mass-constancy drying approach.

Instrumentation Used

• TGM800 thermogravimetric analyzer
• Compressed air supply (oil- and water-free)
• Aluminum foil crucibles (2.4-inch and 1.5-inch)
• 11-place and 17-place carousels

Methodology

Sample preparation involved shredding cheese to a uniform consistency. Approximately 1–3 g samples were loaded into pre-weighed crucibles. The analyzer followed AOAC Official Method 948.12 parameters: ramp from 25 °C to 130 °C at 10 °C/min, 75 min hold (fixed time) or constant mass criteria, and 5 L/min airflow.

Key Results and Discussion

• Fixed drying time (2.4-inch crucible, ~3 g): moisture values averaged 39.7% (Colby-Jack), 48.7% (Mozzarella), 38.0% (Cheddar), 29.9% (Parmesan) with standard deviations ≤ 0.3%.
• Fixed drying time (1.5-inch crucible, ~1 g): results were comparable, with precision below 0.5%.
• Mass constancy method (2.4-inch crucible, ~1 g): similar average moisture values, demonstrating consistency across techniques and sample sizes.

Benefits and Practical Applications

• High precision and reproducibility support quality control in dairy processing.
• Rapid analysis (60–75 min) enables timely decision-making.
• Compliance with official methods ensures regulatory acceptance.

Future Trends and Potential Applications

Advances may include faster ramp rates (up to 20 °C/min), automation for high throughput, integration with real-time process monitoring, and adaptation to other food matrices or moisture analysis requirements.

Conclusion

The TGM800 thermogravimetric analyzer provides a robust, accurate, and AOAC-compliant approach for moisture determination in cheese. Both fixed-time and mass-constancy methods deliver consistent results across cheese types and sample sizes.

References

• AOAC Official Method 948.12, Moisture in Cheese.
• LECO TGM800 Instruction Manual.