A New Method for Total Fat Detection in Raw Milk Based on Dual Low-Coherence Interferometer

Area of Science:

• Optoelectronics
• Biosensing
• Dairy Science

Background:

• Accurate fat content analysis is crucial for raw milk quality control.
• Existing methods for fat detection can be costly and complex.
• Developing rapid, low-cost sensing technologies is essential for the dairy industry.

Purpose of the Study:

• To develop and demonstrate a multimode fiber optic sensing setup for total fat detection in raw milk.
• To evaluate the system's sensitivity, repeatability, and cross-sensitivity to protein.
• To assess the temperature immunity of the proposed sensor.

Main Methods:

• Utilized a multimode fiber optic arrangement with a low-coherence Fabry-Perot cavity.
• Operated the sensor in a dual response mode for phase modulation.
• Tested the system with raw milk samples with varying fat content (0.97%–4.36%) and constant protein (3%).

Main Results:

• Achieved maximum sensitivity of 616 pm/%fat at 500 nm wavelength.
• Demonstrated minimal repeatability error (0.08%) and low cross-sensitivity to protein (0.134).
• Obtained a high regression coefficient (r²=0.9763) and confirmed temperature immunity.

Conclusions:

• The proposed fiber optic sensor is a viable low-cost alternative for detecting minimal fat variations in raw cow milk.
• The system exhibits excellent performance characteristics, including high sensitivity and stability.
• This technology has the potential to improve quality control in the dairy industry.