Detection of irradiated fruits by gas-chromatographic methods

Abstract

To detect those fruits which have been subjected to low-dose irradiation (0.5-3 kGy), two methods of chromatography (GC-MS and LC-LC-GC-FID) were used to determine the radiolytic compounds of lipids formed after irradiation, such as alkanes and alkenes. Extraction of volatile hydrocarbon compounds from some parts of irradiated fruits, e.g. the flesh (avocado), seeds (papaya) and kernels (mango and apricot) was carried out. The analysis of hydrocarbons by GC-MS proved the suitability of using C17:1, C16:2, C15:0 and C14:1 as markers for avocados irradiated with a low dose (0.75 kGy). The same indicators appeared following the analysis of papayas and mangoes irradiated with 1.5, and 3.0 kGy. Also, C15:0, C14:1 and C16:3 can be used to identify apricots irradiated with a low dose (0.5 kGy). The detection of alkenes was only improved by a more selective isolation, e.g. of dienes or trienes by LC-LC-GC-FID. Within a few minutes, apricots and avocados irradiated at low doses (0.5 and 0.75 kGy) can be recognized by the indicators C16:2, C17:2 and C16:3, without interfering peaks. In all cases, C16:1, C16:2, C16:3 as well as significant amounts of C17:2 can be used as markers for fruit irradiation.

Detection of Hydrocarbons in Irradiated Chilled Beef by HS‐SPME–GC–MS and Optimization of the Method

“…The ionization energy was 70 eV. The scanning range was 30-400 m/z in SIM mode, as the hydrocarbons to be detected were known already [22,23].…”

Evaluation of Tissue Culture and Growth Assays to Identify Irradiated from Non-Irradiated Vegetables

“…Due to demand by consumers and many organizations to detect previously irradiated food, several methods have been tried to identify irradiated products. These methods include: chemiluminescence (Mingshia et al, 1992), electrical conductivity (Bhushan and Thomas, 1990;Scherz, 1991), viscosity measurements (Hayashi et al, 1991;Nuernberger and Heide, 1991), gas chromatography (Dohmaru et al, 1989;Schreiber et al, 1990;Farag, 1993), biological methods including measurements of microflora (Hammerton, 1995), germination tests of cereals (Kawamura et al, 1995), and half-embryo culture of fruit trees (Kawamura et al, 1995). An important issue to be addressed when developing a technique to detect irradiation of food is that the technique must be able to discriminate at the practical irradiation dose level.…”