Screening of Aflatoxigenic Property of some Aspergillus flavus Isolated from Sunflower Seeds and its Products at Sunflower Oil Refineries

Aspergillus flavus has become the most widely reported food-borne fungus, reflecting its economic importance and relative ease of recognition as much as its ubiquity. It is especially abundant in the tropics, and it has a particular affinity for nuts and oilseeds as substrates, although the reason is not understood. It is the main source of aflatoxins, the most important mycotoxins in the world's food supplies. It is not necessary that all A. flavus isolates are toxigenic. Some are nonaflatoxigenic. Their toxin producing capability and the amount of aflatoxin production will vary among the A. flavus isolates from various substrates of sunflower oil refinery. Fifty-seven different isolates of Aspergillus flavus were isolated from different samples viz., sunflower seeds, kernels, oil cake, de-oiled cake, raw oil and filtered oil of sunflower oil refineries namely, Nayan Proteins, Lakshmi industries, Raviprakash refinery and Tamil Nadu Agro Industries Corporation Limited. The isolates were grown in YES medium containing 20 % sucrose and 2 % yeast extract. Among these, 52 isolates were aflatoxigenic and produce only aflatoxin B1. The other 5 isolates were non-aflatoxigenic. But all the 57 isolates were not known to produce aflatoxin B2, aflatoxin G1 and aflatoxin G2. Presence of aflatoxins in food and feed and strong evidence of their association with human carcinogenesis, the problem of mycotoxins especially aflatoxigenic property of Aspergillus flavus from sunflower seeds and its products were regarded as worthy of investigation.