COLORIMETRIC ANALYSIS OF FATTY ACIDS USING PCDA VESICLES

Bovine milk is a complex food matrix, composed of essential macro and micronutrients, with lipids being particularly relevant both from a nutritional and economic point of view. The presence of fatty acids directly influences the quality of milk and its derivatives; however, conventional methods of analysis, such as the Gerber test, although widely used, involve the use of potentially toxic reagents and occupational hazards, which may limit their application. Therefore, this study proposed the synthesis and characterization of vesicles formed by 10,12-pentacosadinoic acid (PCDA), with the objective of investigating their potential as a colorimetric sensor for fatty acids present in milk. The vesicles were functionalized with the triblock copolymer L64 and characterized by dynamic light scattering, with an average hydrodynamic radius of 45.38 ± 9.63 nm and a Zeta potential of -24.5 ± 1.92 mV. To evaluate their colorimetric response, seven samples with different concentrations of fatty acids (palmitic acid, oleic acid, and caprylic acid) were added to PCDA vesicles containing Triton X-100. The color changes were recorded by images, and the corresponding RGB histograms were generated in the OriginPro 8.5 software. The vesicles were blue in their initial state and underwent a visible transition to red as the concentration of fatty acids changed.