Filament hygrometer for water activity measurement: interlaboratory evaluation

Area of Science:

• Food Science
• Analytical Chemistry
• Measurement Science

Background:

• Accurate measurement of water activity (aw) is crucial for food stability, safety, and quality.
• Filament hygrometers offer a potential method for aw determination, but require rigorous evaluation.
• Standardization is essential for reliable and comparable aw data across different laboratories.

Purpose of the Study:

• To present and evaluate a method for measuring food water activity (aw) using a filament hygrometer.
• To assess the repeatability and reproducibility of the proposed aw measurement technique.
• To define critical parameters influencing aw measurement accuracy and establish the need for standardized procedures.

Main Methods:

• A filament hygrometer-based method for measuring water activity (aw) was developed.
• An interlaboratory evaluation was conducted under the auspices of the Nordic Committee on Food Analysis.
• Critical parameters affecting aw measurements were identified and analyzed.

Main Results:

• The interlaboratory evaluation demonstrated high precision for the filament hygrometer method.
• Repeatability was found to be 0.005 aw, and reproducibility was 0.010 aw.
• Key parameters influencing measurement accuracy and reproducibility were defined.

Conclusions:

• The filament hygrometer method provides accurate and reproducible measurements of food water activity (aw).
• Strictly standardized procedures for equipment maintenance, sample handling, calibration, and measurement are essential for optimal results.
• This method supports reliable food quality and safety assessments.