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At the outset, let me thank IAEA for selecting India to host this Workshop on Use of Irradiation to Ensure Microbiological Safety of Food.
As you are aware, apart from our main mandate of exploiting nuclear science and technology for generation of electricity, that should be safe, reliable, economical and yet eco-friendly, we also give equal importance on the use of radioisotopes and radiation technology in non-power generation areas like health care, agriculture and food processing, isotope hydrology and industry, including their applications in frontier areas of science and technology.
This Training Workshop on use of Irradiation to ensure Microbiological Safety of Food is, therefore, an important component of our programme on utilisation of nuclear science and technology for improving the quality of life in our six billion plus society.
While discussing on the microbiological safety of food by irradiation, one gets reminded of the fact that during the 19th and early 20th century, milk was responsible for a large number of infant deaths in USA and Europe. In 1860, Pasteur discovered that micro-organisms were the cause of decay and spread of diseases associated with wine and beer. He also demonstrated that heat treatment could preserve wine. This discovery, known as pasteurization, was later more successfully applied to milk to control number of diseases including tuberculosis, typhoid, scarlet fever and several others.
Food is a basic necessity for human existence and perhaps the most precious commodity on earth. Therefore, conservation and preservation of food, which are pre-requisites for food security, have always remained priority to the mankind since time immemorial. It provides the main foundation for economic stability and self-reliance to a nation. India, after achieving self-reliance in agricultural production through green revolution, is able to feed her own people and is also in a position to export agriculture produce. However, increased food production are easily be off-set by factors like the higher rate of population growth, spoilage of food in storage and transportation between the centre of production and the centre of consumption and the seasonal nature of food production resulting in widening gap between demand and supply which have made the need for better preservation and effective utilisation even more relevant today. The hot and humid climate of a country like India is quite favourable for the growth of numerous insects and micro-organisms that cause spoilage of food every year.
It is estimated that as high as 20 - 40% of our agriculture produce is lost due to spoilage by insects, pests and microbes. Presence of microbial contaminants that cause human illness make food products unsafe for consumption resulting in huge economic losses. Providing safe and nutritious food to rapidly expanding population is, therefore, a challenging task for all country’s like India. Hence, there is a strong need to preserve food today in every country world over.
Number of technologies based on thermal sterilization, frozen dehydration and use of chemical preservatives are available for preservation and extension of shelf life of food products. At present, fumigants like methyl bromide, ethylene dibromide and ethylene oxide are used for preservation of food products. Besides being less effective, these fumigants leave chemical residues on food products that are harmful to human health. These fumigants are also harmful to environment and the workers working in the fumigation plant. As per the Montreal Protocol, many countries have already banned the use of fumigants and other countries including India are also planning to phase them out. The obvious alternative is, therefore, radiation processing.
Radiation processing is fast emerging as an important technology for preservation of agricultural commodities and hygienisation of food as well as for sterilization of medical products. It also overcomes the quarantine barrier in international trade of food products. Internationally, this technology has been shown to be an effective, safe and cost effective alternative to some of the existing methods of food processing. Radiation processing technology is particularly important for strengthening the country’s domestic food security as well as to provide access to international trade of food products. Radiation processing involves controlled application of energy of short wave length radiation of electro magnetic spectrum such as gamma rays and x-rays or accelerated electrons. Three types of ionizing radiation are usually permitted for treatment of food:
| (i) |
Gamma rays from either Cobalt-60 with 1.33 MeV or Cesium -137 with 0.67 MeV. |
| (ii) |
X-rays generated from machine source operated at a maximum energy of 5 MeV. |
| (iii) |
Electrons generated from machine source operated at a maximum energy of 10 MeV. |
Radiation passing through or absorbed by the food products produce excitation and ionization in the matter and bring out certain effects through two basic processes, viz.,
| (i) |
Primary Process which causes formation of ions or excited molecules or molecular fragments; and |
| (ii) |
Secondary process involving the interaction of the products (i.e., radicals) of primary events. |
Primary as well as secondary processes give rise to radiolytic/chemical products. Water being the most abundant constituent of most of the foods and cells, radiolysis of water plays a major role in radiation processing of food. When there is plenty of water, indirect effect of radiation predominates through the formation and interaction of radiolytic products with food constituents (like carbohydrate, fats and proteins). But when water content of food is low, direct effect of radiation prevails.
Foods preserved by irradiation do not become radioactive nor does radiation leave behind any harmful residues unlike what happens in food preservation with chemical fumigants. However, there could be some loss of vitamins in some cases which is often minor and could be made up from other sources. Such changes in radiation processed foods are also found in food processed by other methods like cooking, heating, freezing etc., and there is no UNIQUE PRODUCT produced by radiolysis. Irradiation is a cold pasteurization/sterilization process of food without causing changes in their freshness and texture (which are normally associated with thermal pasteurization).
The safety and benefits of food processing by ionizing radiation has been studied extensively world-over, including India for decades and the Joint Expert Committee of Food Irradiation (JFCFR) convened by the Food and Agriculture Organisation (FAO), the World Health Organisation (WHO) and the International Atomic Energy Agency (IAEA) concluded in 1980 that the irradiation of any food commodity upto an overall average dose of 10 kGy presents no toxicological hazards and requires no further testing. JECFR further stated in the case of micro nutrients such as vitamins, losses due to irradiation treatment are comparable or lower to the conventional treatment such as heating or freezing.
Food borne diseases are the major problems not only in developing countries but also in developed countries. According to 1997 WHO Report, cases of food poisoning are on the increase even in the industrialised countries like USA and Japan. In a developed country like USA, application of radiation processing has started in a big way mainly in strengthening food safety and quarantine.
There are more than 60 commercial food irradiation facilities world wide. China, USA, France and South Africa have maximum number of such facilities for carrying out radiation processing of spices, dry vegetables, meat and meat products, potatoes and onions. More than 100 items of food have been approved for radiation processing so far by 28 countries in the world. Several new commercial irradiators dedicated to food processing are under construction in the USA, Brazil, Thailand and other countries. A consortium of companies controlling about 75% of the American ground beef market has started getting their products irradiated in recently commissioned electron beam facilities. Since May, 2000, more than 250 super markets in different states of USA offer radiation processed meat for sale and the number is growing.
India is the second largest producer of food and has the potential to become the number one in due course of time with sustained efforts. As I have already mentioned earlier, growth in food processing industry will bring about immense benefits to the economy by way of encouraging increased agricultural yield at higher productivity, creating employment and rising standard of living of very large number of people throughout the country, specially in the rural areas.
India, with largest producer of fruits – mango, banana, citrus, guva and apple, which account for 70% of food production. In vegetable, only China exceeds India’s production.
In India, the present status of processing of food and vegetable is extremely low at below 2% and India’s share of world trade in this sector is only 1%. Value addition to the raw produce is only 7% compared to as much as 23% in China, 45% in Philippines and 188% in the U.K. Low processing also comes in the way for the industry to achieve economic scale of processing much needed to be economically competitive in the world market.
Sea foods are a major commodity of trade in India with 6 million tonnes of yearly production which ranks third in the world fish production. During the last few years, India has exported processed fishery products worth more than Rs.5000 crores to almost all parts of the world, contributing nearly 4% of the country’s foreign exchange earnings. Fresh fish caught from the seas are normally sterile. But fish and fishery products are highly perishable in nature because of their intrinsic characteristic as well as contamination of a variety of spoilage, causing micro organism. It is estimated that about 25 – 30 % of total fish produced are lost due to their high perishability and, therefore, fail to reach the consumers in the interior parts of the country.
Further, fishery products are known as carriers of pathogenic micro organism, parasites and insects which can be easily taken care of by three irradiation processes such as radurization (for increased shelf life at 1-3 kGy) radicidation (for elimination of pathogenic micro organisms at 4-6 kGy) and radiation disinfestation (for disinfestation by elimination of insects from dehydrated fish products at 0.25 – 1.0 kGy).
Radiation preservation is highly efficient to prevent all lethal bacterial contamination, particularly from salmonella, shigella, histeria and vibro cholerae which are commonly detected bacteria in sea foods.
India has been the home of quality spices since time immemorial. It produces more than 2 million tonnes of spices every year. Most of these spices are consumed within the country. Only about 10% of the produce is exported but it accounts for about 50% of the world export of spices. Since spices are high value commodities, they are an important source of valuable foreign exchange for the country.
Due to low moisture content, spices are inherently stable to spoilage. However, inadequate drying and storage under humid condition during the journey from farm to the table results in spoilage of spices. Presence of invisible micro organisms, many of which could be disease causing, pose risk to human health, especially when spices are added to the food after cooking - a practice more common in western countries. For microbial decontamination, dose of 6 to 14 kGy depending on the type of micro organism and chemical composition of the spices commodity is permissible. Within this dose range, normally used packing materials are not affected (except glass which gets decoloured). Because of much greater sensitivity of insects compared to micro organism, the process of irradiation for microbial purpose does also ensure insect disinfestation.
India losses an estimated Rs.10,000 crores on account of grain and pulses and another Rs.25,000 crores due to vegetable and fruits every year due to shorter post harvest life which can be enhanced significantly by radiation technology. For India, therefore, radiation processing technology holds tremendous promise both domestic food security as well as for higher exports earning.
Main reasons for slow induction of radiation processing technology in developing countries including India are cheaper cost of fumigation process compared to that of irradiation process (which can be easily off-set by installing larger capacity ~ 200 Tes/hr of irradiation plant) and lack of communication and awareness leading to misconception/ignorance about the safety of the irradiated food and inbuilt fear in accepting new technologies. It is, therefore, necessary for the scientific community to bring awareness by practical demonstration of advantages of food irradiation processes to farmers, traders, entrepreneurs, marketing personnel and the public at large through series of dedicated projects/programmes. Once again, I wholeheartedly complement the efforts of IAEA in this direction.
Realising the absolute need and great potential for the irradiation technology for India’s food security, export earnings, employment potential in the villages including the potential to provide price stability for the farmers by avoiding distress sale of the farm products, Food Technology division, BARC has developed, through decades of R&D efforts, the technology for radiation processing of a number of agricultural and food commodities. These include potato, onions, tropical fruits, spices, cereals and cereal products, pulses and pulse products, meat and meat products, sea food and their products which have been approved under Indian Preservation of Food Adulteration Act.
The commercial radiation processing of food in India is regulated by two sets of rules:
| (a) |
Atomic Energy (Control of Irradiation of Food) Rules, 1996. As per these rules, radiation processing of foods can be carried out only in facilities approved by Atomic Energy Regulatory Board (AERB) under the Atomic Energy Act, 1962 (33 of 1962). A license is required for operating a radiation processing facility, which is granted only after a certificate of approval from AERB is obtained. |
| (b) |
Prevention of Food Adulteration Act (5th Amendment) Rules, 1994. |
Food items approved for radiation processing by the Government of India, Ministry of Health & Family Welfare, under the Prevention of Food Adulteration Act (PFA) Rules cover spices, onions, potato, cereals, pulses, meat products and sea foods.
For commercialisation of the radiation technology developed at BARC, a demonstration plant for processing of 30 Te/d of spices is already in operation at Vashi, Navi Mumbai, installed by the Board of Radiation and Isotope Technology. Construction of another demonstration facility (POTON) for irradiation processing at 10 Te/hr of onion will soon be completed at Lasalgaon in Nashik district of Maharashtra, which about 200 kms away from Mumbai.
The country’s first sea food irradiation centre is expected to be set up either at Bhubaneswar in Orissa or at Visakhapatnam in Andhra Pradesh by the respective State Governments to process sea foods for exports.
Two private sector entrepreneurs have also shown interest – one at Vasai near Mumbai for spices and another at Kundli in Haryana for potato, garlic and basmati rice. The Vasai project will have an irradiation capacity of 2 Te/hr while the Kundli project will have a capacity of 25 Te/hr. Both the projects have received site clearance from the Atomic Energy Regulatory Board.
Finally, I do sincerely hope that the deliberations during this Workshop would very be useful to understand how and why radiation technology has become one of the most sought after technologies for preservation of food and improving the hygienic standard of food products, both in domestic market as well as for promotion of exports in the international trade for all the countries in the world. I am also confident that the workshop will assist you to prepare yourself to take initiatives for inducting Food Irradiation technology for the benefit of the society in your respective country.
I wish all success to the Workshop. |
