The danger of calcium carbide in fruit ripening

Ethylene is a natural product of plant metabolism. Even in minute amounts, it can interact with other plant hormones. The process of fruit ripening is regulated by ethylene. Most fruits have high levels of ethylene during ripening.

Centuries old
The effect of ethylene on plants have been known for hundreds of years. Leakage from street lighting can cause premature defoliation. One ripe orange in the lunch box of a truck driver can cause a truck-load of bananas to ripen prematurely. Use of ethylene lamps can hasten ripening on bananas, a common knowledge known amongst goreng pisang hawkers decades ago. 

Accelerating the natural process
The natural process of fruit ripening can be accelerated using a chemical called calcium carbide. When dissolved in water, calcium carbide produces acetylene, a chemical that imitates the effect of ethylene. Ethylene lamps use calcium carbide. You can distinguish the artificially ripened fruit by the uniform skin colour in fruits like tomatoes, mangoes and bananas. In the case of bananas, the entire fruit is a uniform colour of yellow with a green stem and is devoid of any brown spots on the skin or black stalks.

The danger of calcium carbide
Since the amount of carbide needed to ripen the immature fruit is a lot more than the amount of ethylene needed, it makes the fruit become tasteless and toxic. Trace amounts of arsenic and phosphorous in carbide makes the fruit poisonous. Calcium carbide has cancer-causing properties and can cause neurological disorders. If pregnant women consume fruit ripened with carbide, their children could develop abnormalities. 

The use of calcium carbide is not only toxic to consumers, but is also harmul to those who handle it. The practice of ripening fruits using carbide is banned but it is still freely used in Malaysia. In Malaysia, ‘The Food Act 1983’ governs the legislative aspects of food and food-related activities. The law strictly prohibits the use of any substance that may deteriorate the nutritive and/or other beneficial properties of food. The law further prohibits the use and sale of foods containing substances that are injurious to health. Since artificial fruit ripening agents such as calcium carbide and ethylene glycol are harmful for human health; therefore, according to ‘The Food Act 1983’ using those substances for artificial fruit ripening can be considered unlawful in Malaysia.

The only safe method accepted worldwide is the use of ethylene, which is a natural hormone for ripening under controlled temperature and relative humidity conditions. There is a need for the establishment of substantial ripening facilities in Malaysia, owing to the large production of banana in different parts of the country to compliment the growing horticulture industry in Malaysia.