Distance-based ratio metric assay using thread-based devices for Karaya gum detection in food samples

Area of Science:

• Food Science
• Analytical Chemistry
• Microfluidics

Background:

• Karaya gum is a natural thickener used in food products.
• Adulteration with Karaya gum compromises food quality and consumer safety.
• Existing detection methods are often cumbersome and time-consuming.

Purpose of the Study:

• To develop a low-cost, rapid, and portable device for detecting and quantifying Karaya gum.
• To utilize thread-based microfluidics and ratio-metric displacement for Karaya gum analysis.
• To provide an efficient alternative for onsite food safety and quality control.

Main Methods:

• A thread-based microfluidic device was developed using bamboo viscose threads and a chlor-zinc-iodide reagent.
• Ratio-metric displacement was employed, where Karaya gum causes a color change from blue to brown.
• Viscosity measurements, FTIR analysis, and grayscale quantification (Fiji software) were used for confirmation.

Main Results:

• The device achieved a limit of detection of 0.1% w/v for Karaya gum.
• The blue-to-brown colorimetric ratio was directly proportional to Karaya gum concentration.
• The method was successfully validated in a field trial using a commercial basil drink.

Conclusions:

• The developed device offers an efficient and portable solution for Karaya gum detection.
• This approach has significant potential for rapid, onsite food safety and quality control.
• The method provides a reliable alternative to conventional, complex analytical techniques.