Novel analytical method detects genotoxic compounds in edible oils

Edible oils rich in unsaturated fatty acids are essential components of a healthy diet. However, food safety problems existing in these seemingly healthy oils can be overlooked. Recently, a new study by Prof. Gertrud Morlock, Chair of Food Sciences at Justus Liebig University Giessen and her Ph.D. student, Daniel Meyer, found that healthy oils recommended for daily consumption may contain a considerable amount of genotoxic compounds hazardous to human health. The study, published in the journal Food Chemistry, also demonstrates the application of newly developed non-target planar genotoxicity profiling method for detecting genotoxic compounds in edible oils.

Genotoxic compounds are substances that can induce DNA damage and are potential carcinogens. They are widely present in a variety of sources, including food, air, and water. While some well-known genotoxic compounds are easily detected and regulated, others may be overlooked due to the selective nature or lack of sensitivity of current analytical techniques. The researchers hypothesized that some less studied genotoxic compounds are present in healthy food materials that escape detection and exist as a source of hazards in the household products. Thus, the development of a more sensitive and untargeted bio-analytical method is much needed. To this end, they sampled 33 oil samples including 31 healthy oils from local households and studied them under different household storage conditions. Analysis using a planar genotoxicity bioassay that combines separation with effect detection on the same surface allows sensitive detection of genotoxins in the oils. This bioassay employs high-performance thin-layer chromatography coupled with a genetically modified Salmonella typhimurium strain equipped with the SOS-Umu-C repair mechanism. The genotoxic compound zones were then characterized by high-resolution mass spectrometry.

The study revealed that genotoxic substances, such as epoxides and hydroperoxides produced due to the oxidation of unsaturated fatty acids, were detected in multiple oil samples. Moreover, the amount of genotoxic compounds in the oils increased with prolonged storage and air exposure. This is the first method capable of detecting genotoxic compounds in edible oils, in a generic and sensitive manner.

Overall, the study has important implications for public health and food safety. It provides a potential solution to the problem of detecting a spectrum of genotoxic compounds in foods and other sources. It also highlights the need for more sensitive and accurate analytical techniques that can cover a wide range of toxic compounds in food analysis. On top of this, the study underscores the importance of continued research into the sources of genotoxicity in food, feed, dietary supplements, and cosmetics.

In the future, more studies are needed to redefine good manufacturing practices, safe product formulations, and proper storage conditions to ensure the stability of oil-rich foods, feeds, dietary supplements, and cosmetics over the recommended product shelf life. Additionally, the authors suggest that analogous non-target screenings could be used to further analyze compounds with neurotoxic, cytotoxic, antimicrobial, and endocrine effects in complex samples. Finally, the authors advocate that an analytical paradigm shift toward non-target planar image-based genotoxicity screening could be applied in routine analysis of complex household samples to ensure consumer safety.