Detection of Irradiated Apricot Fruits During Storage

To detect the fresh and irradiated apricot fruits which have been exposed to low doses of gamma rays (0.3 and 0.5 kGy), two recommended methods by European Committee for Standardization (EN 1784, 1996 and EN 1787, 2000) were used to study the possibility for identification of irradiated fruits. Fresh apricots (Amar variety) were irradiated at low doses (0.3 and 0.5 kGy) whereas the dried apricots were irradiated at 3 and 5 kGy. The first method was carried out to determine the free radicals by using electron spin resonance (ESR) on dried layers of apricot kernels either in irradiated fresh or dried samples. The results proved that ESR intensity were more sensitive for all applied doses beside the possibility of detection of the irradiated stored fresh sample after storage (3 weeks) and dried (9 months). The linear relationship resulted between ESR intensity and applied doses showed high significant of R2 for the irradiated samples either fresh or dried. The ESR intensity was decreased gradually during long storage period but can identified clearly than nonirradiated samples. The second method was carried out to determine the volatile hydrocarbons (VHC) by using florisil column identified by gas chromatography - mass spectrometry (GC-MS). The major VRC were C14:1, C16:2, C16:3 and C17:2 at different doses which were increased linearly with increasing the dose either at low or high doses. Some VHC such as 16:1 and 17:1 were only detected at high dose (3 kGy). Fresh or irradiated fruits could be detected during storage by using inside kernels and EU methods, mainly ESR and VHC, either at low or high doses even at low doses during short time and high accuracy.