Corn flour Photo: IC

Eight family members in Jixi of Northeast China's Heilongjiang Province have died after eating homemade corn noodles, while another family member is currently in hospital receiving treatment. Local authorities confirmed on Monday that they were poisoned by toxic bongkrekic acid found in the noodles, and they had ruled out any possibility of intentional poisoning.

The family, with 12 members in total, ate breakfast at home together on the morning of October 5. All nine elders ate the homemade noodles before falling ill, while the three younger people did not eat because they did not like the taste, local government said. 

The corn noodles they consumed are actually a local food called Suantangzi, which is a thick type of noodle made from fermented corn flour. However, a high concentration of bongkrekic acid, a respiratory toxin produced by the bacterium pseudomonas cocovenenans, was detected in the corn noodles, and also in the gastric fluid of the elders, the Health Commission of Heilongjiang Province said.

Notably, the homemade food had been frozen in the family's refrigerator for nearly one year.

Bongkrekic acid is extremely toxic, resistant to high temperatures, and cannot be removed even if thoroughly cooked, Fan Zhihong, an associate professor of China's Agricultural University, was quoted by the Beijing News. Currently, there is no medicine available to treat such cases of poisoning, she said.

Bongkrekic acid is the main cause of poisoning from fermented flour products, spoiled fresh white fungus as well as other spoiled starch products, experts said. To avoid poisoning, experts reminded the public to avoid using soaked or moldy corn to make food, and to not make or eat any food made from fermented grains.

Eating food contaminated with bongkrekic acid can result in poisoning for both humans and animals and even lead to death, with a morality rate as high as 40 to 100 percent, according to experts.