Proposal of the revised sampling plans for aflatoxin test of shelled peanuts and pistachios under the GLP system in Japan

Effects of the revised sampling plans for the aflatoxin (AF) inspection of raw shelled peanuts and Pistachios were examined by statistical evaluation. Instead of the present method for preparing a single sample that is composed of 1kg from a lot, the multi-sub-sampling plans were prepared as follows. For small kernel peanuts, three 1kg sub-samples from a lot imported from countries where low incidence of AF contamination might be expected to occur, and five 1kg sub-samples from a lot imported from countries where high incidence of AF contamination might be expected to occur were prepared. If all of the 3 or 5 sub-samples are not over the regulation level of AFB1 (10 micro g/kg), the lot should be accepted. For large kernel peanuts, 2kg of sub-samples were prepared as the same manner of small kernel peanuts. The detoxifying percentage (DP), the consumer's risk (CR), and the processor's risk (PR) of these multi-sub-sampling plans were evaluated by Whitaker's negative binominal distribution method. Statistical indexes were estimated at 56.2% (DP), 3.5% (CR) and 6.1% (PR) in the case of 3 sub-sampling plan, and were 66.6%, 2.0% and 9.3%, respectively, in the case of 5 sub-sampling plan. For the inspection of pistachios from Iran, the present method of 8 sub-sampling method should be kept because of its maximum limit as routine work. Furthermore, it is necessary to harmonize the sampling methods in the National government (Mycotoxin Research Association, MRA) and the local governments. In the case of the inspection by local governments, the inspected result should be effective on limited part of the lot presenting at markets or food shops, because sampling size are smaller than MRA. If a large scale of the lot is existent, the local governments should carried out the multi-sub-sampling plans like as MRA.