Application of Calcium Alginate Spheres Modified with 2,4-Dinitrophenylhydrazine During the Determination of Fatty Aldehydes in Edible Oils by HPLC-DAD

Saturated fatty aldehydes are products from lipid oxidation that negatively affect the organoleptic properties and nutritional quality of food and represent a risk to human health. For this reason, they are frequently used as indicators of oxidation in food safety. Usually, their determination is carried out by derivatization using an excess of 2,4-dinitrophenylhydrazine (DNPH), but the excessive use of derivatizing agents requires a high proportion compared to the analyte concentration to ensure a complete reaction, which causes interferences and limits the chromatographic separation of derivatized products. In this context, the encapsulation of DNPH in alginate spheres is proposed to determine aldehydes concentration in edible vegetable oil samples, allowing the gradual release of DNPH to form the corresponding hydrazones, which were subsequently separated and analyzed by HPLC-DAD. The proposed method was optimized by a Taguchi L9(34) experimental design, validated, and applied for the determination of aldehydes in edible oils. Limits of detection in the intervals of 0.77 to 1.41 mg L−1 were obtained with adequate precision (expressed as relative standard deviation < 10%), which are suitable values for monitoring lipid oxidation in foods The proposed methodology represents a viable alternative to apply in quality control studies and lipid degradation profiles.