Sources in the department say that although chemical substances like calcium carbide stone and ethylene spray are banned, vendors continue to use them to ripen fruits such as bananas, watermelons, chiku (sapota) and mangoes to make a quick buck. 

“Vendors would usually use calcium carbide stones as it helps to ripen fruits within 12 hours. But such chemicals create health hazards for consumers,” said an official. Other chemicals like ethylene powder and spray are also used by vendors, he noted. 

A retail fruit vendor, who makes wholesale purchase of fruits from Koyambedu market, admitted that there are several such instances particularly during the summer period. “Since natural ripening takes a long time, traders prefer to use chemicals for artificially ripening. They do so for saving time,” the vendor said. 

On being contacted by DT Next, R Kathiravan, designated officer, Tamil Nadu Food Safety Department, Chennai, said, “Consumers should not be tempted to buy fruits which have a polished appearance. It is advisable that they check the colour of fruits.” 

The department, which keeps a vigil on wholesale and retail fruit vendors resorting to this tactic, has warned action against violators. They recently seized 3.25 tonnes of chiku, 1 tonne of mango and 750 kg bananas, all of which were artificially ripened, in Koyambedu market, Kathiravan said, adding that inspections on fruit shops would continue in the city.