Bitter truth about fruit

In the haste to ripen fruit, chemicals and ripening agents are used by retailers. Natural taste and nutrition value become a casualty of this process but there is no system in place to check this practice. Ruchika M. Khanna reports

Remember when the aroma of mangoes would waft and tempt your tastebuds as soon as you saw the basketful of the luscious fruit? Or how bananas would melt in your mouth? Ever wondered how these, and many other popular fruits, are losing their their taste, aroma, and nutrition value, even as they have a uniform and attractive colour?

As traders and retailers are under pressure to ensure a regular supply of fruits, much before their due time of arrival in the mandis, all kinds of unscrupulous methods are used to ripen fruits artificially. These include reactions with calcium carbide and other chemicals to make the appearance of fruit attractive—notwithstanding the fact that the genetics of fruits are being compromised, as is the health of millions of consumers.

The brightly coloured fruit might be laced with chemicals
The brightly coloured fruit might be laced with chemicals

The problem is more severe in the case of mangoes and bananas, and sometimes apples, papayas, guavas, pears and plums as well. Though it is suspected that even water melons and melons are ripened artificially by injecting some chemicals, horticulture scientists deny this outright, saying that it is scientifically not possible to inject a chemical in melons.

However, the Horticulture Departments, Mandi Board officials and Health Departments refuse to acknowledge the gravity of the problem, and the need to take corrective action. In fact, while all three government agencies say they are aware of these illegal and harmful techniques for advancing ripening of fruits by traders, they are quick to shift blame on one another for failing to curb the practice.

Incidentally, this practice is banned under the Prevention of Food Adulteration Act, and violators are liable to undergo a six-month imprisonment and pay a fine of Rs 1,000. But there are hardly any cases where the traders or retailers have been booked for accelerating ripening by the use of harmful chemicals.

Since the fruits are sent to different places, requiring several days at ordinary or refrigerated transportation, only firm, but mature fruits are least damaged during marketing. They are ripened at the destination markets before retailing.

"Artificial ripening of fruits is done for commercial purposes with chemicals. However, fruits thus readied are both toxic and tasteless. If the fruit is uniformly well coloured, or if black blotches appear on the skin in two or three days, you could suspect chemical ripening," says Dr Kamal Thakur, Associate Professor, Department of Post-Harvest Technology, Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan.

Though many techniques are employed to ripen mature fruits, the most commonly used agent is calcium carbide. It has carcinogenic properties and is used in gas welding for steel goods. This method is being used in most of the climacteric fruits (fruits which are picked when mature, and ripened only after they are picked) like mangoes and bananas. No wonder, health freaks who go on a fruit diet to keep fit, often end up with mouth ulcers, gastric irritation or even food poisoning. So much for a fruit diet.

Calcium carbide, popularly known as masala, is used extensively in mangoes, bananas and papayas, and sometimes in apples and plums. "Being cheap (one kg of this chemical costs Rs 25-30, which can ripen 10 tonnes of fruit), it is indiscriminately used by the traders in preference to other recommended practices of inducing ripening like dipping fruits in a solution of ethephon, or exposure of fruits to ethylene gas," says Dr B.V.C Mahajan, Horticulturist, Punjab Horticulture Post-Harvest Technology Centre, Ludhiana.

Using calcium carbide is also a less cumbersome procedure. All that a trader has to do is wrap a small quantity of calcium carbide in a paper packet, and keep this packet near a pile of bananas, or a box of mangoes or other fruits. This box is kept in a closed space for one or two days. As chemical reaction takes place, because of moisture content in the fruit, heat and acetylene gas are produced, which hastens the ripening process. In case of bananas, the ripening starts within 24 to 48 hours, depending on the ambient temperature and when the fruits yield to slight finger pressure, they are kept under ice slabs for lowering temperature and the colour develops. However, fruit ripened with calcium carbide are overly soft and less tasty. They also have a shorter shelf life.

"Not only is it harmful to the consumers, but it is also dangerous to handle calcium carbide and acetylene because of their explosive properties. The chemical is so reactive that it causes blisters, if it is touched unknowingly with wet hands," says Dr Mahajan.

What is being done to counter this adulteration? Nothing. True, but the horticulture and health authorities seem unconcerned over the extensive use of chemicals in fruits. While 78 per cent of the total horticulture produce in Himachal are apples, 23 per cent in Haryana are mangoes. In Punjab, mangoes are cultivated in Ropar and Hoshiarpur. Officials in Punjab Mandi Board say that about 120-150 tonnes of mangoes (from May-August) and about 200-250 tonnes of bananas (from August-December) and 50-60 tonnes (from December-February) arrive in the mandis of Punjab daily. In spite of this high consumption of fruits, and the obvious shift to horticulture as part of the crop-diversification plan, authorities have failed to devise any action plan to check malpractices in ripening.

Inquiries from officials in the Food and Adulteration wing of both Punjab and Haryana Health Departments revealed that they had never collected any samples of fruits to test for chemicals used for ripening. "We have never come across any complaint for collecting fruit samples, so an exercise has never been undertaken," said a top Health Department official in Haryana. They say that the civil surgeons in the district or the Food Inspectors can be contacted to lodge complaints about the use of chemicals.

The Horticulture Department officials in the two states, while washing their hands off the issue, were quick to point out that their service was restricted to increasing fruit production and extension services. They, however, failed to acknowledge that educating farmers, traders and retailers about the safe methods of artificial ripening, as against use of calcium carbide, was a part of their extension services.

Luckily, the agricultural universities have stepped in to fill this gap in extension services, and they are now holding regular camps to educate traders against use of calcium carbide. "Earlier, we would hold camps thrice a year, but considering the extensive use of chemicals, we are holding these awareness camps almost once a month now," said Dr Mahajan. Dr Kamal Thakur, too, said that apple growers and traders in Himachal were being taught regularly about safe methods of ripening, and to avoid the use of harmful chemicals.

Photos: Parvesh Chauhan and Vinay Malik

How they get ripe & ready

Ripening is a continuous process and there is no single point of time when a fruit can be universally declared as "ripe". Anatomically, fruits are swollen ovaries that may also contain associated flower parts. Initially, fruits enlarge through cell division and then by increasing cell volume. The embryo matures, the seed accumulates storage products and loses water—which is the stage when the fruit begins to ripen. The carbohydrate, protein and lipid in the fruit undergo conversion, causing changes in texture, colour, taste and aroma. Ethylene a simple hydrocarbon gas that ripening fruits make, and shed into the atmosphere, initiates the entire ripening process. This ethylene signal causes new enzymes to be made in the fruit and these enzymes, catalyse reactions to alter the characteristics of the fruit. Chlorophyll is broken down and new pigments are made so that the fruit skin changes colour from green to red, yellow, etc. Acids are broken down so that the fruit changes from sour to neutral. The degradation of starch by amylase produces sugar. This reduces the mealy quality of the fruit and increases sweetness and juiciness. The breakdown of pectin between the fruit cells unglues them so they can slip past each other. That results in a softer fruit. The enzymes also break down large organic molecules into smaller ones that evaporate into the air—which we detect as aroma.

The right way to store

Storing unripe fruits in a brown paper bag (with a few holes), keeping them amidst straw, or placing an apple in their midst are some, age-old tricks to speed up ripening. These work because, the bag/straw traps the ethylene given off by the fruits, and hastens the ripening process. Apples help because they give off particularly large quantities of ethylene. This also explains the wisdom in the saying, "one bad apple can spoil a basket!" Fruits and vegetables should ideally be stored separately. Many vegetables are sensitive to ethylene and may discolour, change texture or change taste in its presence.

Look before you eat

  • Wash the fruits thoroughly before consuming. Keep these under running water for a few minutes, so that the chemicals are washed away.

  • Do not buy fruits when these arrive in the mandis before the due period. You can be almost sure that they are artificially ripened for better marketing and earning profits.

  • While eating mangoes and apples, cut the fruit into pieces, rather than consuming directly.

  • What looks attractive outside may not be good for health. Fruits that have a uniform colour, for example, a bunch of bananas having a uniform colour, are more likely to have been artificially ripened.

Fruit bowl of the north

Himachal Pradesh, Punjab and Haryana are the major fruit- producing states in the northern region. While the total horticulture produce in Himachal was 6.95 lakh metric tonnes, the produce in Punjab was 7.31 lakh metric tonnes. Over 51,000 hectares of area in Punjab is under fruit cultivation, while it is 24,000 hectares in Haryana. Citrus fruits, mainly kinnows, are the main fruits grown in Punjab, while it is mangoes in Haryana and apples in Himachal.