Smartphone-Based Spectrophotometer for Facile and Fast Determination of Lipid Peroxidation in Local Fried Food

Abstract

During lipid peroxidation in foods, deterioration rancidity occurred, and a toxic by-product also accumulated. The well-known marker of lipid peroxidation in food is malondialdehyde (MDA), suspected to be carcinogenic and mutagenic in humans. MDA level is determined using thiobarbituric acid (TBA) assay. The pink color of the MDA-TBA2 complex after the reaction can be measured spectrophotometrically at 530-540 nm. Several analytical methods, including smartphone-based methods, have been used to determine the MDA-TBA2 complex, such as UV-Vis spectrophotometry and HPLC-DAD. Therefore, this research aimed to determine lipid peroxidation in fried food using a simple smartphone-based spectrophotometer. The device was established using a paper box, LED lamps, and a test tube. Various concentrations of MDA were reacted with TBA reagent and then submitted to the device. RGB intensity data were converted to absorbance values and used to construct linear regression. Results showed that the G value from the smartphone-based spectrophotometer provided consistent results with R2 of 0.9869, including 0.93 and 95.17% precision and accuracy, respectively. Then, the developed device was finally used to determine the MDA in local fried food samples. The concentration of MDA in fried foods was successfully determined with high precision (0.96) and accuracy (88.33 %) compared to the traditional UV-Vis spectrophotometric method. Thus, this study provides a practical guideline for developing quick and easy accessibility, portability, and low-cost spectrophotometer for lipid peroxidation assessment in fried food and other future food matrices.