Alkylcyclobutanones are widely used as chemical markers of irradiated foods which contain lipids. Alkylcyclobutanones are radiolytic products generated by fatty acids and can be used to determine whether foods have been exposure to the irradiation.
Figure 1. Examples of foods containing lipids
For the irradiation testing of foodstuffs containing lipids, most methods are based on the chemical measurement of compounds produced from the irradiation of fatty acids components. When the triglycerides containing fatty acids in the foodstuffs are treated with irradiation, 2-substituted alkylcyclobutanones are produced as radiolytic products. Ionizing radiation induces the production of a variety of alkylcyclobutanones and hydrocarbons from fatty acids within the lipid molecule. The main fatty acids present in most foodstuffs include stearic, palmitic, linoleic, and oleic acids. These fatty acids are converted to their corresponding cyclobutanones after the exposure to irradiation. The loss of an electron from the oxygen on the carbonyl of a triglyceride or fatty acid can result in the formation of these cyclic based compounds alkylcyclobutanones. Then 2-alkylcyclobutanones specific to the parent fatty acid are generated by a rearrangement process. Alkylcyclobutanones contain the same number of carbon atoms as the parent fatty acids.
There have been many advances in new methods of isolating alkylcyclobutanones and analytical techniques. The improvement on the specificity and sensitivity of this method is still undergoing. Many efforts are also on the extension of the scope of this method to detect the use of irradiated ingredients in composite foods. The amount of alkylcyclobutanones formed by irradiation is often related to the radiation dose and the temperature as well as the concentration of the precursor fatty acid. The type and quantities of foods usually do not affect the proportions of the fatty acids.
The method based on the determination of alkylcyclobutanones is a standard method in the European Committee for Standardization. The analytical methods that are commonly used to determine alkylcyclobutanones formed by food irradiation are based on the extraction of the lipid fraction of foods using a solvent. Then the lipid phase is fractioned on a column of deactivated Florisil or silica. Alkylcyclobutanones are separated from lipids by gas chromatography and detected using mass spectrometry. Many foods contain fat and the method should be applicable to a wide range of foods with a suitable fat extraction procedure. Many studies have been focused on the speeding up of the extraction process and the improvement of the clean-up step. The alkylcyclobutanones in the non-irradiated foods should also be minimized to avoid false positive results.
The procedure for the food irradiation testing using alkylcyclobutanones based methods includes sample preparation and pretreatment, fat extraction, and detection using gas chromatography couple with mass spectrometry. We have expertise in the sample preparation of a variety types of foodstuffs. The sample preparation has a significant effect on the accuracy of the level measured in the food samples.
We offer an accurate and validated alkylcyclobutanones based platform for the identification and detection that have been widely applied in the food irradiation testing to meet customers' needs. We also maintain high quality assurance for the food irradiation analysis.
* Not intended for personal food safety testing.