Bent Fiber Sensor for Preservative Detection in Milk

Area of Science:

• Optical Sensors
• Biomedical Engineering
• Food Science

Background:

• Refractive index sensing is crucial for analyzing liquid properties.
• Plastic optical fibers offer a cost-effective sensing platform.
• Detecting milk adulteration requires sensitive and accurate methods.

Purpose of the Study:

• To develop and characterize a bent plastic optical fiber sensor.
• To assess the sensor's sensitivity to refractive index changes in milk.
• To evaluate the sensor's capability for detecting milk preservatives.

Main Methods:

• Utilizing bent plastic optical fibers with varying bending lengths.
• Measuring refractive index changes in low-fat milk samples.
• Introducing common milk preservatives (formaldehyde, hydrogen peroxide, sodium carbonate) at varying concentrations (0-14.3%).

Main Results:

• The sensor demonstrated high sensitivity, detecting refractive index changes below 0.4%.
• A strong linear correlation was observed between preservative concentration and the sensor's normalized response.
• Refractive indices ranged from 1.34550 to 1.35093 with increasing sodium carbonate concentration.

Conclusions:

• Bent plastic optical fiber sensors offer a promising approach for milk quality monitoring.
• The sensor's linearity and sensitivity enable accurate detection of adulteration.
• This technology can be applied to ensure food safety and authenticity.