By: Mrityunjay Anand *
Food is one of the most important necessities in life. Fortunately, many advanced and several developing countries have abundant supplies of fresh, safe and nutritious foods. Yet, despite the many precautions and processes in place to ensure a safe food supply, microbial contamination is still a concern, even in advanced countries. There are a number of food processing tools available that provide additional protection for the foods we consume. One very promising tool is food irradiation, which is a process of imparting ionizing energy to food to kill microorganisms.
Food safety is a global issue with paramount environmental and public health consequences if inadequately maintained. With the increased globalization of food supply, ensuring the safety of this supply to consumers has become an international collaborative endeavor. The concern for ensuring food safety can be illustrated by the extent of food-borne illnesses around the world. Therefore, a variety of procedures have been developed and used to reduce food-borne contamination. It is not a substitute for safe food handling and good manufacturing practices by processors, retailers, and consumers alike, since bacteria could be reintroduced later.
What is Food Irradiation?
Food irradiation is the process of exposing food to an ionizing energy to kill harmful bacteria and other organisms, and extend shelf-life. It is a safe process and has been approved by many countries worldwide for many years. Approved irradiated foods include fruits, vegetables, meat, poultry, fish and seafood, roots and tubers, cereals, legumes, spices and dried vegetable seasonings etc. Irradiation can also help meat; poultry and seafood keep longer by reducing spoilage-causing microbes.
How Does Food Irradiation Work?
Irradiation with gamma-rays, X-rays or fast electrons can be used to change foodstuffs in beneficial ways or to destroy harmful organisms. Gamma rays do not induce radioactivity in foods, but X-rays and fast electrons can induce short lived radioactivity if sufficiently energetic. This imposes limitations on the energies which can be used, and a short wait between irradiation and consumption may be advisable. Irradiation produces chemical changes in foodstuffs, and some foods are unsuitable for irradiation. With appropriate foods, trials with animals and human volunteers generally show that the product is safe. Some loss in nutritional quality can take place, which could be significant for some individuals, but are unlikely to be important for those on a balanced diet. Irradiation does not eliminate all risk from microbial contamination. The food is never in contact with the energy source; the ionizing energy merely penetrates into the food but does not stay in the food. It takes very little energy to destroy harmful bacteria. At these levels there is no significant increase in temperature or change in composition. Irradiation does not make food radioactive nor does it leave any residues. The levels of ionizing energy used to treat foods for pathogen reduction or disinfestation are measured in kiloGrays (kGy). A low-to-medium dose of below 1-10 kGy is usually sufficient to render a product safe from harmful bacteria or insects such as fruit flies, while causing little or no effects on product quality or nutrition. Foods to be irradiated should be good quality, and need to be kept under proper conditions after irradiation. Irradiated foods should be appropriately labelled. Tests for radiation would help to enforce necessary controls. If the process is properly carried out on appropriate foods, and all due precautions are taken, irradiated foods are wholesome and safe.
What Are the Benefits?
The most significant public health benefit of food irradiation is that it stops the spread of foodborne disease. It greatly reduces or eliminates the number of disease-causing bacteria and other harmful organisms that threaten us and our food supply. Many of these organisms, including Salmonella, Escherichia coli (E. coli), Staphyloccoccus aureus, Listeria monocytogenes have caused many outbreaks of foodborne illness. When food is irradiated, the penetrating energy breaks down the DNA molecules of the harmful organisms. The food is left virtually unchanged, except that it is much safer because the number of harmful organisms is greatly reduced or eliminated. An added advantage is that food can be irradiated in its final packaging – fresh or frozen, which prevents the possibility of contamination in the distribution system, at the store, or even in the home, prior to the package being opened. Although reduction of disease-causing bacteria is of greatest importance to public health and safety, there are other significant benefits of food irradiation. Irradiation can also help keep meat, poultry and seafood fresh longer by reducing the level of spoilage-causing microbes. It also allows consumers to keep certain fruits and vegetables fresh longer.
It is important to note that toxins, viruses or bacterial spores are resistant to irradiation. Therefore, it is essential that irradiation be used in conjunction with all other established safe food handling and good manufacturing practices.
How widespread is Food borne Illness?
Food borne illness outbreaks have been associated with almost every food commodity: dairy products, eggs, meats, seafood, poultry and fruits and vegetables. Outbreaks can occur because of cross contact during food handling, processing and home preparation. A growing concern to many health officials is the emergence of new strains of bacteria and other organisms. One example is E. coli.
Food irradiation can be a boon for consumers and have a phenomenal impact on the safety and growth of the global food supply. Internationally renowned organization including the World Health Organization (WHO) has embraced this technology for the food safety benefits it provides.
What Are Consumers’ Reactions?
Research has shown that consumers are enthusiastic about purchasing clearly labeled irradiated food for themselves and their families, including children, after they have been informed of the safety and benefits of the technology. Consumers also indicated that, for irradiated foods, safety and taste were more important than price, and they believed that eliminating harmful bacteria was a more valuable benefit than extended shelf-life. Market tests conducted in the past decade, have indicated that consumers were willing to purchase irradiated foods when they understood the benefits. Nevertheless, more education is necessary for consumers to become more familiar with the process and its benefits.
How Is Food Irradiation Regulated?
Several national food control authorities have extensively studied this food process under a variety of conditions and found it to be safe and effective. In India, the Department of Atomic Energy and Food Safety and Standards Authority of India (FSSAI) either approve or establish guidelines for food irradiation.
The Atomic Energy (Radiation Processing of Food and Allied Products) Rules, 2012 comprehen-sively covers the regulatory consent requirements, the certification of the personnel authorised to handle radiation sources, the administrative procedures to be adopted for use of radiation sources, the technical conditions and the managerial aspects aimed at ensuring safety in the use and handling of the radiation sources, management of the radioactive wastes and the irradiation of food. These rules were promulgated 1991 which were later amended in 1994, 1996 and 2012 and these rules prescribe the technological conditions for the food irradiation, the qualification of the Radiation Safety Officer, the Operators and the Quality Control Officer, the various conditions for the operation of the irradiation facility, the dosimetry aspects etc. The Certificate of Approval is issued after verifying that the design of food irradiation facility conforms to the standards and qualified staffs are available for its safe operation. Under these rules, the Competent Authority, i.e. Chairman, AERB issues Certificate of Approval.
In terms of Food Safety and Standards (Food Product Standards and Food Additives) Regulations, 2011, ‘Irradiation’ means any physical procedure, involving the intentional exposure of food to ionizing radiations. ‘Irradiation facility’ means any facility which is capable of being utilized for treatment of food by irradiation. ‘Irradiated food’ means articles of food subjected to radiation by:-
(i) Gamma Rays;
(ii) X-rays generated from machine sources operated at or below an energy level of 5 million electron volts; and
(iii) Sub-atomic particles, namely, electrons generated from machine sources operated at or below an energy level of 10 million electron volts, to dose levels as specified in under the Atomic Energy (Radiation Processing of Food and Allied Products) Rules, 2012.
‘Operator of irradiation facility’ means any person appointed as such by licensee who satisfies the qualifications and requirements as for training specified in under the Atomic Energy (Radiation Processing of Food and Allied Products) Rules, 2012.
Under Regulation 2.13 of Food Safety and Standards (Food Product Standards and Food Additives) Sixth Amendment Regulations, 2016, the doses of irradiation in different types of food is prescribed, wherein it is stated that “No article of food permitted for irradiation specified in column 2 of the Table under Regulation 2.13.1 (2) shall receive the dose of irradiation in excess of the quantity specified in column 3 of the said Table at the time of irradiation.” The requirement for the process of Irradiation, restriction on Irradiation of food and its sale, standards of Irradiated food, its labeling requirement and the records of Irradiated food are prescribed under these regulations.
In terms of Regulation 2.13.8 of Food Safety and Standards (Food Product Standards and Food Additives) Sixth Amendment Regulations, 2016, the label of a food, which has been treated with ionizing radiation, shall carry a written statement indicating the treatment in close proximity to the name of the food.
All packages of radiation processed food shall bear the Radura logo in green colour and following declaration, namely:-
It makes easy for consumers to determine if a food has been irradiated. Regulations require that irradiated food be labeled as such and often it may be accompanied by food irradiation logo.
Is Food Irradiation Safe?
Yes, if it complies with all the requirements. Food has been irradiated in several countries for many years resulting in products that are safer for consumption than the untreated original foods. According to the WHO, the renowned global authority on public health, “Food irradiation is a thoroughly tested process and when established guidelines and procedures are followed, it can help ensure a safer and more plentiful food supply.”
A number of compounds are formed when food is irradiated, just as there are when food is cooked or exposed to other processing methods. However, based on hundreds of scientific tests, there is broad agreement among scientists and health agencies that these compounds are not a human health issue. In fact, more chemical changes occur when toasting bread or barbecuing steak than when irradiating food.
Food irradiation provides an added layer of protection to food without significant changes to taste, nutritional value, color or texture. Since irradiation does not substantially raise the temperature of food or “cook it,” taste and nutrient losses are small and considerably less than other methods of preservation, such as canning, drying or heat pasteurization. Carbohydrates, fats and proteins are the main components of food, and a wide body of research has shown that these nutrients do not change significantly during irradiation. Some vitamins, most notably the B vitamins, have some sensitivity to irradiation, but processors can minimize nutrient losses by irradiating food in an oxygen-free environment or a cold or frozen state.
Is Irradiation the Answer for Food Safety?
While food irradiation is an important process that promotes food safety, it is not a substitute for safe food handling by processors, retailers and consumers. Although food irradiation may kill many organisms in food that is already spoiled, it cannot suppress odors or other signs of spoilage, and thus cannot be used as a means to “hide” or “cover up” spoiled food. Bacteria and other microorganisms that produce bad odors or discoloration will still exist as a warning sign to consumers that a food has spoiled, even after the food has been irradiated. In addition, food irradiation goes hand-in-hand with modern Hazard Analysis and Critical Control Points (HACCP), a preventative food safety management system that is mandated in many countries.
Consumers must practice safe food handling techniques, whether the food is irradiated or not. It is still possible for bacteria to multiply in irradiated food if it has not been refrigerated properly or if care was not taken to avoid cross contamination with harmful bacteria from other sources.
* Technical Officer, FSSAI