Toxic aldehydes in fried foods: Formation, analysis, and reduction strategies

During high-temperature frying, heated culinary oils undergo thermooxidative degradation of unsaturated fatty acids, resulting in the generation of harmful aldehydic lipid oxidation products. The presence of toxic aldehydes in food is a significant concern for consumers as well as industries in terms of food safety. Based on this, we conducted a search in the WoS database using “frying” and “aldehydes” as topic, combined bibliometric methods to analyze the published relevant literature, summarize the current research progress, and evaluate future development trends. This review focuses on the latest advancements in understanding aldehydes formation, harmful effects, analysis techniques, occurrence in food, and reduction approaches. Acrolein, 2,4-decadienal and 4-hydroxy-2-nonenal (HNE) are primarily formed through linoleic acid oxidation, while linolenic acid contributes to the production of 4-hydroxy-2-hexenal (HHE). Commonly used methods for determining aldehydes include HPLC and GC-MS. However, to meet the demand for rapid and convenient analysis, techniques such as FTIR, NMR, and electrochemical methods have gained advantages. These methods offer the potential for further optimization of experimental conditions to develop precise quantitative methods suitable for “in-situ” determination. To reduce the production of aldehydes, the application of antioxidants has been considered as an effective method and future research should focus on identifying effectively antioxidant, particularly natural antioxidants, to reduce aldehyde formation during food processing. These efforts will contribute to the production of safer and higher-quality food products.