Defence scientists come up with non-electric technology to keep fruits, vegetables fresh in inhospitable climate, but army yet to accept it

The fact that Indian troops stationed in inhospitable terrain have difficulty accessing fresh fruit and vegetables is well known. What is not is that the Defence Food and Research Laboratory (DFRL) has invented two non-electric devices to help them out.

The 'zero-energy cooling chamber' is a portable device that keeps farm produce fresh in high temperatures while the 'anti-freeze device' is for use in cold climes to prevent fruits and vegetables from becoming rock hard instead of staying soft and chewy.

DFRL sources said testing on these devices was completed in 2007-08, but the army is yet to grant the budget to induct them.

Evaporation cooling

The zero-energy cooling chamber "works on the principle of evaporation cooling, similar to water cooling in earthenware," said the sources.

The device has a container, inside which there is a smaller container holding the fresh farm produce.

Water is left to drip into the outer container and percolate through the walls, resulting in a decrease in temperature between 6 degrees Celsius and 9 degrees Celsius relative to the surroundings.

The containers can be made of metal, plastic or even double-walled brick.

The storage capacity of the inner container varies from 30 kilograms to 200 kilograms.

Turning on the heat

The anti-freeze containers have storage capacities of 30 kilograms to 80 kilograms.

"The containers are double walled, with high density polyurethane filling between the walls," said a DFRL source.

The container has a platform underneath for heaters, which hold two types of chemicals a solid one and a liquid one in a sachet. When the sachet is pierced, the chemicals come in contact, leading to a heat-releasing chemical reaction.

With four such sachets of 25 grams each, the temperature can be increased by 10-12 degrees Celsius relative to the surroundings, and kept so for 24 hours in case of the 30 kg containers.

DFRL sources said they hoped the army would allot the necessary funds for these devices in the Union Budget.

What is DFRL?
The Defence Food Research Laboratory (DFRL) was formed in 1961 at Mysore to look into the food issues of the armed forces. This is the only laboratory to be engaged in this field so extensively. Over the past 35 years, the laboratory has been able to preserve, stabilise and engineer a vast array of foods, which have long shelf lives, but do not lose their nutritional values while in storage.