An improved rapid physicochemical assay method for aflatoxin in peanuts and peanut products

A rapid, sensitive and economic method for the detection, quantification and confirmation of aflatoxins

A rapid, sensitive and economic method for the detection, quantification and confirmation of aflatoxins is described. Aflatoxins B1, B2, G1, and G2, are extracted by methanol/water (85 + 15) and partitioned into methylene dichloride. The methylene dichloride solution is cleaned up on a polypropylene column, filled with 0.5 g silica gel 60. The aflatoxins are eluted with chloroform-acetone (90:10) and are detected using bidirectional thin-layer chromatography (TLC) with aluminium silica gel foil. The mean recovery of aflatoxins B1, B2, G1, and G2 in corn samples was 73, 78, 80, and 64%, respectively; the limit of detection was 0.5 micrograms/kg. The results can also be confirmed by derivative formation using trifluoroacetic acid on the TLC plate. The method has been applied to a wide range of foods with good results.

Natural occurrence of zearalenone and toxicogenic fungi in amaranth grain

Zearalenone was detected as the natural contaminant in two samples of Amaranthus cruentus grains (1980 micrograms/kg and 420 micrograms/kg, respectively). Fungi isolated from these samples were screened for mycotoxin production. Two of eight isolates of Fusarium (F. equiseti and F. moniliforme) produced zearalenone. One of four isolates of Aspergillus flavus and all four isolates of A. parasiticus produced aflatoxins. Other species potentially toxicogenic such as Aspergillus versicolor, Penicillium viridicatum, P. puberulum, P. crustosum, P. citrinum, P. expansum and Fusarium solani were also found.

Aflatoxin B1 production in orange (Citrus reticulata) juice by isolates of Aspergillus flavus Link

Out of 7 isolates of Aspergillus flavus obtained from rotting orange (Citrus reticulata) fruits, 3 isolates were found to be toxigenic, producing variable amounts of aflatoxin B1 on a semisynthetic liquid medium. The most toxigenic isolates were further evaluated in plain juice and juice supplemented either with 0.05% yeast extract or 0.5% sucrose or both, at three different incubation periods. The maximum yield of aflatoxin B1 (162.5 micrograms/25 ml) was obtained from the juice supplemented with both sucrose and yeast extract within an incubation period of 10 days, whereas a sharp decline in aflatoxin B1 (30 micrograms/25 ml) was observed when incubation was extended beyond 10 days. The addition of yeast extract has a promoting effect on the yield of aflatoxin in comparison to the sucrose.