By: Rakesh Lohumi, Sr. Editor-ICN Group
SHIMLA: Extensive use of irradiation technology to minimise post-harvest crop losses is imperative to ensure food security in a developing country like India with meagre land resources and a burgeoning population.
Increasing production alone will not help given the unacceptably high levels of post-harvest losses which wipe out more than one-third of the total food and foodgrain production.
While exact data for post-harvest crop losses is not available various independent studies and government reports estimate the losses from 35 to 55 percent. Globally the magnitude of loss varies widely for various crops ranging from 20 percent for cereals and root crops to over 50 percent for fruits and vegetables.
The percentage of loss is on the higher side in India, particularly in case of perishable food items like potato and onion, of which the country is the largest producer in the world. The annual loss on account of spoilage of food, including fruits, vegetables, cereals, meat, pulses and flowers estimated to be over Rs. 2,50,000 crore.
The country’s current foodgrain production of 252 million tonne (2015-16) is enough to meet the requirement of 1.25 billion population.
However, with limited arable the land ensuring food security for the ever increasing production population will be a big challenge. According renowned agriculture scientist M.S. Swaminathan the population will be around 1.8 billion in 2025 and after taking into account the requirement of farm animals, livestock and poultry the production will have to be almost doubled.
Thus, to increase food availability on a sustainable basis and ease pressure on natural resources the focus has to be on reduction of the post-harvest losses. The food irradiation technology developed by the Food Technology Division of the Bhabha Atomic Research Centre has a vital role in preservation of food.
It can prevent bulk of post-harvest losses which are primarily caused due to insect infestation, microbiological contamination, and physiological changes due to sprouting, ripening, and senescence. The hot and humid climate of India is conducive for the growth of insects and microorganisms that destroy stored crops and cause spoilage of food.
Radiation processing technology involves the controlled application of energy from ionizing radiations such as gamma rays, electrons, and X-rays for food preservation. It can be used for inhibition of sprouting in bulbs and tubers, disinfestations of food grains and pulses, ensuring microbiological safety and minimising spoilage bacteria, insects and parasites, and delay ripening in certain fruits and vegetables.
Irradiation works by disrupting the biological processes that lead to decay. It is a direct, one-time process in which low, medium high doses of radiation are applied to prevent spoilage and enhance shelf life.
For instance, a low dose of 0.15 kilo Gray (unit of absorbed radiation energy equivalent to 1 Joule per kilogram) can arrest sprouting of potatoes and onions. It helps to contain losses of tubers and bulbs due to sprouting and their dehydration substantially.
Low dose (up to 1 kGy) applications also helps in disinfestation of insects in stored grain, pulses, and food products and the destruction of parasites in meat and meat products. Similarly, a medium dose (1 to 10 kGy) eliminates microbes in fresh fruits, meat, and poultry products, destroys food pathogens in meat, and helps in the hygienization of spices and herbs. A high dose (above 10 kGy) can be applied to produce shelf-stable foods and carry out sterilization of food for special requirements.
Low dose irradiation kills the common grain pests and even the eggs deposited inside the grains. A single radiation exposure of grains is sufficient for disinfestations. Irradiation can also effectively disinfest pre-packed cereal products like atta, soji (rava) and premixes.
Sprout inhibiting dose of radiation is also effective in destroying tuber moth, a devastating pest of potato. Thus, irradiation provides an effective solution to the storage problems of potatoes. Thus, it can be used on a large-scale to preserve food and prevent post harvest losses to bring substantial economic benefits to farmers.