In the Philippines they ripen mangoes in baskets at the markets with calcium carbide, which is not a safe chemical. It is unhealthy for the workers, and can even be flammable.
|Mangoes ripen artificially at Bankerohan Market, Davao City|
Our project researchers at University of Queensland have developed a new product in Australia which generates ethylene for ripening in a safer way. The lab results look good, so the project has been extended to further test this promising work on a safer way to ripen mangoes!
‘We now know that this safer method works in the lab. Extending this project will give us time to make sure it works in the mango baskets at the fruit markets of the southern Philippines,’ says ACIAR Horticulture expert Dr Richard Markham.
To ripen fruit now, retailers pack green fruit in newspaper-lined bamboo baskets for three days. Calcium carbide is wrapped in newspaper and placed in the center of the basket. Fruit and wrapped calcium carbide are tightly tied with plastic twine. The top is covered with newspaper pieces used to line the container. The temperature of fruit pulp during the ripening of mango could reach up to 350C.
|Workers stay close to the mangoes - and the chemicals|
When in contact with moisture from the fruit, calcium carbide generates acetylene and heat which accelerate the ripening process. Acetylene mimics the action of ethylene in ripening fruit.
Calcium carbide is readily available and cheap. It is widely used as an artificial ripening agent of ‘Carabao’ mango in the local market. It emits unpleasant odor. Calcium carbide is banned in many countries, as this cheap ripening agent poses health risks as it contains traces of arsenic and phosphorus. Stall holders remain with their ripening fruit waiting for the markets to open.
|ACIAR project members examine ripe mangoes|
ACIAR set up this project to test safer alternatives, for the market sellers and the buyers. So far the results look very good - it will be exciting to see what the next phase of this project will bring to the fruit markets in the Philippines.
From Leizel B. Secretaria, and ACIAR
Improved postharvest management of fruit and vegetables in the southern Philippines
HORT/2012/098 - http://aciar.gov.au/project/hort/2012/019