BRIGHT GREENISH YELLOW FLUORESCENCE AS A PRESUMPTIVE INDICTOR OF AFLLATOXINS IN AGRICULTURAL COMMODITIES

Study was conducted on different cereals (wheat, rice, sorghum) and oil seeds (sunflowerseed, cottonseed, groundnut) to correlate bright greenish yellow fluorescence (BGYF) of the seeds under longwave (366 nm) ultraviolet light with aflatoxin presence.\ud \ud Correlation between BGYF, aflatoxin and kojic acid contents and peroxidase units indicated that samples showing BGYF were not always contaminated with aflatoxins but those which contained aflatoxins, always exhibited BGYF. It was further noticed that all the samples, that showed BGY fluorescence and aflatoxin presence were loaded with spores of Aspergillus flavus. Aflatoxin positive samples also had high moisture contents. Storage of the BGYF and aflatoxin positive samples showed that storage in the dark increased the aflatoxin content and in the light, the aflatoxin content was reduced.\ud \ud Some varieties of cereals and oil seeds were contaminated with toxic strain of A. flavus. Results showed positive relationship between BGYF and aflatoxin production. Varieties with high quantities of aflatoxin also showed high quantities of kojic acid. Some varieties showed profused growth which was accompanied by increased production of aflatoxin and BGYF units. Activity-of enzyme peroxidase varied from variety to variety.\ud \ud In case of naturally contaminated cotton seed (Indian variety), a direct relationship was recorded between the number of BGYF kernels and aflatoxin content. Thin layer chromatography of the extracted BGYF material from cotton seed and standard BGYF material prepared chemically showed the same Rf. and fluorescence characteristics. It is concluded from the results that a positive relationship existed between A flavus infection, BGY fluorescence and aflatoxin content and thereby supported the use of UV induced BGY fluorescence as a presumptive indicator of aflatoxins in different agricultural commodities