FTIR spectroscopy as a tool to detect contamination of rocket (Eruca sativa and Diplotaxis tenuifolia) salad with common groundsel (Senecio vulgaris) leaves

BACKGROUNDRocket is a popular salad vegetable used all over the world and it has many health benefits. However, like with all plant material, there exists a danger of contamination with toxic substances. In the case of rocket, contamination with groundsel has occurred. Groundsel is a common weed in rocket crops, and it contains very toxic pyrrolizidine alkaloids. In our study infrared spectroscopy was used to distinguish groundsel samples from rocket leaves. Infrared spectroscopy is a very simple analytical technique; however, some specific conditions are more easily implemented in industrial environment than others. Some of these conditions and parameters of infrared spectroscopy were explored in detail. RESULTSWe tested for the influence of different parameters of attenuated total reflectance and transmission infrared method. Our results show that a 100 % correct classification can be obtained under conditions most suitable for industry: using fresh samples and parameters that enable fast spectral measurement. CONCLUSIONInfrared spectroscopy is a fast and easy-to-use method that has been shown to be able to differentiate between rocket and groundsel leaves. Therefore, it could be further studied for implementation in the safety control of rocket salads. (c) 2016 Society of Chemical Industry