Aflatoxin contamination in insect damaged seeds of horsegram under storage

Abstract

Studies on one of the protein rich pulses, horsegram (Dolichos biflorus L.) were carried out to know how far these low risk pulses are free from aflatoxin contamination under severe insect infestation in storage. A total of 150 stored seed samples of horsegram were analyzed for the presence of aflatoxins by collecting 25 samples each of undamaged and insect damaged seeds of all the three varieties (PDM-1, PHG-1 and HG-96). More than 33% of insect damaged seed samples were contaminated with aflatoxin B1 and B2, whereas less than 8% of the undamaged seed samples contain only low levels of aflatoxin B2. Higher levels of aflatoxin B1 (up to 130 μg/kg) were reported in insect damaged seed samples of all the three varieties under study. The levels of aflatoxin B2 were always lower than aflatoxin B1 of the corresponding seed samples with insect damage. Aflatoxin B1 was reported in both the undamaged and insect damaged seed samples of all the three varieties of horsegram. It is evident from the varietal response studies that PDM-1 and HG-96 varieties of horsegram are highly vulnerable to aflatoxin contamination whereas, PHG-1 variety is relatively less susceptible to it. In general, insect infestation leads to increase in fungal invasion (including aflatoxigenic fungi) and this further enhances the levels of aflatoxin contamination in horsegram seeds.

Farmers knowledge, perceptions and management of Kersting’s groundnut (Macrotyloma geocarpum Harms) insect pests in Benin

“…Heavily infested kersting's groundnut grains are consumed by the interviewed farmers. However, there are reports of a strong relation between insect infestation and aflatoxins contamination in some pulses such as horsegram (Reddy, Brijitha, & Raghavender, 2005), grass pea (Reddy & Nusrath, 1983), cowpea, and pigeon pea (Matumba et al, 2017) which are poisonous and contribute to the genesis of primary liver cancer in Africa (Koshio et al, 2017;Peers, Gilman, & Linsell, 1976). It is therefore urgent to assess the presence of mycotoxins in Kersting's groundnut seeds heavily infested with insects and to raise farmers' awareness on the harmful effects of mycotoxins on human health.…”

Mycotoxin contamination of commercially important agricultural commodities

“…It is well adapted to low rainfall and high temperature, and thus can be grown in areas where other cereal crops such as wheat or maize would not survive. Pearl millet grain is not as susceptible to mycotoxin contamination as groundnut and cereals like maize and sorghum, but can become contaminated with A. flavus and A. parasiticus (Reddy BN, et al, 2005). Raghavender et al (2008) documented 35 fungal species representing 14 genera in stored pearl millet seed samples harvested during the rainy season, and 30 species belonging to 20 genera were found in pearl millet harvested during the dry season.…”

“…Hence, it is grown as a common crop in poor, gravelly soils and in regions of low rainfall. B. N. Reddy et al (2005) examined 25 samples each of stored undamaged and insect-damaged horse gram seeds of three varieties (PDM-1, PHG-1, and HG-96) for aflatoxins. Aflatoxin B1 was observed in both the undamaged and insect-damaged seed samples of all the three varieties of horse gram, with higher levels of aflatoxin B1 (up to 130 gkg −1 ) in insect-damaged seed samples.…”

Potential of aflatoxin B1 production by Aspergillus flavus strains on commercially important food grains

“…Greengram and horsegram also found susceptible to AFB1 accumulation ranging from 645.8 to 2245.2 and 1134.0 to 4589.6 μg kg −1 . Reddy et al. (2005) first time in India reported up to 130 μg kg −1 of AFB1 on insect‐damaged horsegram seeds.…”

“…Greengram and horsegram also found susceptible to AFB1 accumulation ranging from 645.8 to 2245.2 and 1134.0 to 4589.6 lg kg )1 . Reddy et al (2005) first time in India reported up to 130 lg kg )1 of AFB1 on insect-damaged horsegram seeds. Still today, no attempts have been made to study the AFB1 production by A. flavus strains on greengram and horsegram seeds.…”