Effects of gamma radiation in mycotoxin descontamination of Aloysia citrodora Paláu
Conference Paper
Overview
Overview
abstract
The interest and demand for aromatic and medicinal plants have been growing due to their combined
organoleptic and bioactive properties. However, in general these plants suffer natural contamination by
fungi and associated toxins during growth as also in harvesting, storage and drying processes, which
represents a threat to public health. The rigorous standards required by the industrial sector in terms of
good quality of raw materials demand efficient decontamination procedures (1-3). Gamma radiation is
assumed as an accredited methodology for the decontamination of medicinal and aromatic plants, with
numerous advantages not only to the product itself but also to the consumer and the environment (4).
In this study, efficient methods for detecting aflatoxins (AFB" AFB2, AFG1 and AFG2) and ocratoxin A
(OTA), were optimized and validated, and afterwards, applied to spiked samples of Aloysia citrodora
Pahiu submitted to gamma radiation treatment at different doses (I , 5 and I 0 kGy ), to evaluate the
effectiveness of irradiation as a decontamination technique for dry plants. Mycotoxin levels were
determined by reversed-phase high-performance liquid chromatography (HPLC) with fluorescence
detection, after immunoaffinity column (lAC) cleanup. All the applied gamma radiation doses conducted
to a degradation of the studied mycotoxins. In relation to the control sample (0 kGy), the reduction rates in
the irradiated samples ranged from 4.9 and 5.2% in OTA, 5.3 and 9.6% in AFBt. 12.3 and 13.5 in AFB2,
16.4 and 23.6 in AFG1 and, finally, 52.6 and 62.7% in AFG2. The gamma radiation dose of 5 kGy stood
out as the best decontamination dose for AFB1 and AFG1, which are the most significant aflatoxins
naturally found in food commodities. For OTA, AFG2 and AFB2 there was no significant difference in
decontamination between doses. In conclusion, the extraction and analysis methods proved to be suitable
for detection of aflatoxins and ocratoxin A in A. citrodora. Gamma radiation seems to be an effective
technique for reducing aflatoxins G in A. citrodora, and eventually oth~r medicinal and aromatic plants.
On the other hand, aflatoxins B and OTA are less affected by this treatment.
