Four unprocessed Indian spices sampled at the point of export were shown to be highly contaminated with bacteria. Bacillus cereus was detected in more samples of these spices than any other spore-forming aerobe.

Seeds of twenty-two cowpea (Vigna unguiculata (L.) Walp) lines/cultivars were inoculated with Aspergillus parasiticus (Link) (NRRL 3145) and aflatoxin production was evaluated. All the cowpea samples were susceptible to Aspergillus infection and subsequent aflatoxin production. The amount of aflatoxin produced ranged between 466.6 micrograms/kg to 1 806 micrograms/kg in the case of B (B1 + B2) and 20.8 micrograms/kg to 82.7 micrograms/kg of seed in the case of G (G1 + G2). On the basis of the amount of aflatoxin produced on different samples, it is evident that there is at least partial resistance to aflatoxin production in the tested cowpea lines/cultivars. On the basis of the results obtained in this investigation it is apparent that further selection and breeding could provide cowpea cultivars which are resistant to A. parasiticus infection and aflatoxin production.

No abstract

Black peppercorns supported the growth of Aspergillus parasiticus (flavus) NRRL 3145. Incubation at 28 C and RH of 85% for 30 days resulted in profuse conidial production on the reticulate ridges of the peppercorns. An SEM study of these ridges showed that they were cortical eruptions, and the particulate matter present favored mycelial establishment. Hyphal anastamoses were commonly observed. Following this incubation the inoculated peppercorns were stored in the dark at room temperature and ambient humidity for 15 days. Aflatoxin was detected on minicolumn. Aflatoxin B1 was produced at levels of 60 micrograms/kg with traces of aflatoxin B2, G1 and G2. Quantitative estimation was based on a visual comparison with standards by thin-layer chromatography.

The minicolumn of Holaday and Lansden was modified by increasing the height of neutral alumina and including a layer of anhydrous sodium sulphate. Using this procedure, aflatoxin was detected in 18 of 125 samples of black pepper, red pepper, ginger and turmeric. A few samples of each spice contained aflatoxin, although red pepper and turmeric showed the highest incidence. Aflatoxin B1 quantities ranged from 10 ug/kg to 120 ug/kg when estimated quantitatively by visual comparison with standards on thin-layer chromatography plates.