Variations of moisture measurements in cheese

Area of Science:

• Dairy Science
• Analytical Chemistry

Background:

• Accurate cheese moisture determination is crucial for yield prediction and quality control.
• Official methods like AOAC, International Dairy Federation, and Standard Methods for the Examination of Dairy Products (SM) are widely used.
• Interlaboratory trials reveal variations in results obtained by different laboratories and methods.

Purpose of the Study:

• To evaluate the effectiveness of officially recognized cheese moisture determination methods.
• To identify sources of error and bias in interlaboratory moisture analysis.
• To propose a method for improving the accuracy of cheese yield prediction formulas.

Main Methods:

• Conducted interlaboratory trials comparing AOAC, International Dairy Federation, and SM methods for cheese moisture determination.
• Compared official methods against alternative methods involving freeze-drying and vacuum oven drying with sand.
• Analyzed data from multiple trials to assess laboratory performance and method variability.

Main Results:

• Officially recognized methods (AOAC, IDF, SM) did not completely remove moisture from cheese samples.
• These methods yielded results approximately 0.2% lower than methods that ensured complete moisture removal.
• Significant variability was observed in results among participating laboratories, indicating potential biases and systematic errors.

Conclusions:

• Current official methods for cheese moisture determination are insufficient for complete moisture removal.
• Laboratory-specific biases can impact the accuracy of cheese yield prediction.
• Implementing a system with reference laboratories using a complete moisture removal method is proposed to correct predictive yield formulas.