WASHINGTON: Sunflower seeds are frequently contaminated with a potent toxin produced by moulds, and pose an increased risk of liver cancer, a new study warns.
Researchers from Michigan State University (MSU) in the US documented frequent occurrence of aflatoxin - a toxin produced by Aspergillus moulds that commonly infect corn, peanuts, pistachios and almonds - in sunflower seeds and their products.
They analysed aflatoxin levels of seeds and cakes in seven regions of Tanzania in 2014 and 2015.
Nearly 60 per cent of seed samples and 80 per cent of cake samples were contaminated with aflatoxins.
Researchers found that 14 per cent of seeds and 17 per cent of cakes were contaminated above 20 parts per billion, the level considered safe by the US Food and Drug Administration. Some samples had levels of several hundred parts per billion.
The study was conducted in Tanzania, but the problem is by no means isolated there. Chronic exposure to aflatoxin causes an estimated 25,000-155,000 deaths worldwide each year, from corn and peanuts alone. It is one of the most potent liver carcinogens, researchers said.
"These high aflatoxin levels, in a commodity frequently consumed by the Tanzanian population, indicate that local authorities must implement interventions to prevent and control aflatoxin contamination along the sunflower commodity value chain, to enhance food and feed safety in Tanzania," said Gale Strasburg of MSU.
The seeds of the sunflower become infected by Aspergillus flavus or Aspergillus parasiticus, moulds that produce aflatoxin.
This contamination has been well studied in other crops, but there is little research published on sunflower seed contamination, researchers said.
The study was published in the journal PLoS ONE