Following an increasing number of reports of vomiting and stomach pain after consuming cherry tomatoes, local health and agriculture authorities on Thursday pointed to a substance in tomatoes called ‘tomatine’ as the main cause of the gastric distress.

Naturally produced as the tomato plants grow, tomatine normally decomposes when tomatoes begin to ripen. The substance is a chemical that allows the plants to resist negative changes in the environment, such as attacks by insects or temperature variations.

The South Chungcheong Province Agricultural Research and Extension Services announced that a certain variety of cherry tomatoes -- HS2106 -- is likely to contain an unusually high level of tomatine as the average temperature of late January, which reached minus 7.2 degrees Celsius on Jan. 25, was three degrees lower than the average year.

Exposure to colder weather conditions led to the overproduction of tomatine in HS2106 cherry tomatoes, and children and families who consumed tomato products with the tomatine remnants have ended up developing gastrointestinal symptoms, the agency explained.

It added that other varieties of cherry tomatoes didn't have any food safety issues.

Recently, some online mom forums and communities have been bombarded with posts reporting that their children vomited and had stomachaches after eating cherry tomatoes.

“My daughter threw up a few hours after she ate cherry tomatoes at school. She is better now. I thought she had food poisoning,” one user wrote.

According to the Ministry of Food and Drug Safety, all the reported cases of children’s stomach problems involved the HS2106 tomatoes. It confirmed that no relationship has been found between the cases and common causes of food poisoning such as bacteria or residual pesticides.

Meanwhile, the HS2106 cherry tomatoes were produced by three farms in South Chungcheong Province. One of them discarded all the products to prevent them from circulating in the market. The Ministry of Agriculture, Food and Rural Affairs ordered the other two tomato growers to temporarily halt shipping their products and to voluntarily collect those that have been already delivered to farm goods wholesalers.

The government will allow the farms to resume the shipment if their products pass its screening to see whether they contain tomatine, officials said.

Symptoms like vomiting or abdominal pain after eating cherry tomatoes containing tomatine may disappear within an hour, but it is recommended to visit the nearest hospital for treatment if you have eaten a large quantities of the cherry tomatoes or the symptoms become severe, medical experts say.