Abstract:
Bananas are a main source of vitamins and minerals among various kinds of tropical fruits.
However, its consumption is becoming less due to intentional chemical usage for artificial
ripening which causes serious health hazards. Ripening is normally a natural process
through which the fruits gradually become sweet, colored, soft and palatable. Fruit sellers
artificially ripen the fruit to meet customers’ demand and to overcome transportation and
distribution issues.
Ethylene is the major ripening agent produced naturally within the fruits which initiates the
process of ripening. However, ethanol, methanol, ethylene glycol, ethephon and calcium
carbide are used to ripen fruits artificially. The use of calcium carbide has been banned in
many countries due to its high toxicity. Ethephon has been used in Sri Lanka for artificial
ripening of mostly bananas, papaw and mangoes. When ethephon (2
chloroethylphosphoric acid) is used for ripening of fruits, ethylene gas is released which
helps to accelerate ripening. Ethephon is hazardous and there are no reliable methods to
detect such chemically treated fruits in the Sri Lankan market.
This research proposes a design of an electronic device which will automatically carry out
the detection process and provide an indication of the concentration of the applied
chemicals. The detection is done electronically by measuring the conductivity of the water
in which the banana is rinsed. The design consists of three main units, detection unit,
controller unit and power supply unit. In the testing, the banana sample is rinsed with
distilled water and the conductivity of the rinsed water is measured by using a conductivity
sensor. The reading is then displayed on a digital screen with the indication on the
presence of chemicals to assess whether chemically treatment has been carried out. The
testing process is automated by using a microcontroller.
The preliminary testing was conducted for two types of artificially ripened bananas (Ambul
and Suvandel) with known ethephon solutions. Significant differences were recorded in
comparison with the readings obtained for naturally ripened bananas. The detection
method can also be extended to other fruits to investigate the use of ethophone or artificial
ripening. It is expected that the proposed device would be useful for inspectors of food and
consumer safety for detecting illegally ripened bananas without destructing of the fruit.
