Effects of gamma radiation in mycotoxin descontamination of Aloysia citrodora Paláu

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.

Microbiological and physicochemical aspects of “salpicão”, a traditional dry sausage produced in the northeast of Portugal

Counts of total viable mesophilic bacteria (TVC), lactic acid bacteria (LAB), Microccocaceae, Enterobacteriaceae, Salmonella spp. and Listeria monocytogenes, in traditional Portuguese dry sausages from two industrial producers, were compared in batter and final product. During the production process, the TVC increased significantly, most likely due to the multiplication of fermentative flora. Enterobacteriaceae decreased from batter to final product while the S. aureus increased. Great variability was verified in detection of L. monocytogenes both between batches and industrial producers