Objective quantification of free fatty acids in edible oils using RGB sensor-based multi-wavelength colourimetric...

Area of Science:

• Analytical Chemistry
• Food Science Technology

Background:

• Visual titration for free fatty acids (FFAs) in edible oils lacks objective endpoints, impacting reproducibility.
• Current methods rely on subjective colorimetric assessments, failing to provide consistent quantification.
• The Malaysian Palm Oil Board (MPOB) standard for neutralization lacks objective reference points.

Purpose of the Study:

• To develop an objective RGB sensor-based multi-wavelength colorimetric titration method for quantifying FFAs in edible oils.
• To overcome the limitations of subjective visual endpoint determination in conventional titration.
• To enhance the accuracy and reproducibility of FFA quantification in edible oils.

Main Methods:

• Evaluated red cabbage extract and phenolphthalein pH indicators for titration.
• Utilized an RGB color sensor to monitor color changes during titration with different illumination sources (lasers, LEDs).
• Applied data normalization and classification techniques, with MATLAB used for FFA content computation.

Main Results:

• Laser illumination resulted in sharper spectral transitions and reduced signal noise compared to LEDs.
• A positive linear correlation was observed between RGB values and FFA concentration in cooking oil.
• FFA content was measured at 0.33% for cooking oil and 0.45% for olive oil.

Conclusions:

• RGB sensor systems with optimized illumination and data analysis improve titration endpoint accuracy.
• This method supports the development of cost-effective, portable tools for oil quality monitoring.
• The approach holds potential for real-time, in-situ monitoring in industrial and consumer applications.