Gamma Irradiation Technology in Food Processing: Exploring Government Grants and Benefits

What is Food Irradiation?

Food irradiation is a process that uses ionizing radiation to extend the shelf life of food and ensure its safety by reducing or eliminating microorganisms and pests. This technology involves exposing food products to gamma rays, X-rays, or electron beams in a controlled environment.

How It Works

1. Source of Radiation: Food is exposed to ionizing radiation from sources like Cobalt-60 or electron beam accelerators.
2. Energy Transfer: The radiation energy is absorbed by the food, disrupting the DNA of microorganisms, insects, and other pests, rendering them inactive or killing them.
3. Controlled Environment: The process is conducted in a highly regulated and controlled environment to ensure safety and effectiveness.

Goals of Food Irradiation

• Elimination of Pathogens: Destroys harmful bacteria, viruses, and parasites that can cause foodborne illnesses.
• Insect Disinfestation: Eradicates insects in stored grains, fruits, and vegetables without the use of chemical pesticides.
• Delay of Ripening and Sprouting: Extends the shelf life of fresh produce by slowing down the ripening process and inhibiting sprouting.
• Sterilization: Used for sterilizing spices, dried herbs, and certain medical products, ensuring they are free from microorganisms.

• What is Gamma Irradiation?

  Gamma irradiation is the process of exposing various products to ionizing gamma rays (similar to UV and X-rays) in a highly controlled manner to eliminate viruses, bacteria, pathogens, insects, and other undesirable organisms. Gamma rays, a form of electromagnetic radiation with very short wavelengths, act as a source of ionizing energy that destroys bacteria and pests.

  The isotope Cobalt-60 is the most common source of gamma rays for irradiation processing. Cobalt-60 is manufactured specifically for the irradiation process and is housed in specially designed, doubly encapsulated stainless steel pencils within a system operating to strict standards and regulations.

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• Cobalt-60 can be stored safely in a pool of water, while the chamber above the pool is surrounded by a thick concrete barrier to prevent gamma rays from escaping when the gamma source is elevated into the irradiation chamber. Products intended for medical sterilization are packaged, palletized, and transported into the irradiation chamber using a conveyor.
• Gamma irradiation is known as a ‘cold process’ because the temperature of the processed product does not increase significantly. It is also a chemical-free process that is not reliant on humidity, temperature, or pressure.

How Does It Work: Process Flow

• 1. Arrival and Unloading: Products arrive on a truck and are unloaded at the gamma irradiation processing facility.
  2. Loading and Exposure: The product is loaded into the carrier/tote as per established configurations and sent into the radiation cell where it is exposed to the radiation field (Cobalt-60 source rack).
  3. Circulation and Dosage: The product is circulated around the radiation source for a specific amount of time to impart the requisite dose.
  4. Completion and Shipment: Upon completion of the cycle, the products are brought out, unloaded, released, or shipped back to the user.

  Gamma irradiation as a means for sterilization is a proven technology developed in the late 1950s and is used in over 50 countries for various applications.

  Facts About Gamma Irradiation

  • Treatment with gamma radiation does not make the product radioactive.
  • Irradiation does not affect or change the nutritional value of the treated foods.
  • Irradiation is a completely safe and clean method of hygienizing products, with no harmful byproducts or significant temperature increase.
  • Many countries, including the USA, New Zealand, and Australia, mandate irradiation as a treatment prior to importing certain food products.

  Benefits of Gamma Irradiation

  1. Significant increase in shelf life for many products.
  2. Elimination of harmful bacteria, viruses, and pests.
  3. Cold and clean process (no temperature rise or residue).
  4. Treatment after final packaging, eliminating the need for repackaging

  Applications of Gamma Irradiation

  • Hygienization: Spices
  • Polymer Modification: Polymers
  • Insect Disinfection: Cereals, pulses, fresh fruits
  • Coloration: Gems
  • Sterilization: Syringes and medical supplies
  • Shelf Life Extension: Fish, fresh meat
  • Sprout Inhibition: Potato and onion
  • Sludge Hygienization: Dry sludge
  • Quarantine: Mango and pomegranate

  Key Terminologies Associated with Gamma Irradiation

  • Absorbed Dose: The amount of energy transferred to the product by radiation, measured in Gray (1 Gray = 1 J/kg).
  • Source Strength: The power of the radiation source used for processing, measured in Curie (Ci) or Becquerel (Bq) (1 Ci = 3.7 x 10¹⁰ Bq).
  • Plant Throughput: The amount of product (in kg) processed by an irradiation plant per hour, day, etc.
  • Radiation Absorption Efficiency: The fraction of radiation energy emitted by the source that is absorbed by the product.
  • Dose Uniformity Ratio (DUR): The ratio between the maximum and minimum doses absorbed by the product in a package (DUR = Maximum dose / Minimum dose).
  • Product Changeover Time: The total time taken to replace one product with another (of varying density) for irradiation.

  Food Preservation by Radiation

  Food irradiation is a technique used to reduce microorganisms in food. Depending on the dose, microorganisms, bacteria, and viruses are either killed, slowed down, or prevented from reproducing. This method decreases or eliminates the risk of foodborne illness. Some foods receive enough radiation to sterilize them, preventing pathogenic or spoiling bacteria from being added to the final product.

  Why is Food Irradiated?

• • Prevention of Foodborne Illness: Eradication of organisms like Salmonella and E. coli.
  • Extension of Shelf Life: Preservation and destruction/inactivation of organisms leading to food degradation.
  • Control of Insects: Eradication without the use of pest-control chemicals.
  • Delay Ripening and Sprouting: Prevents premature ripening or sprouting of fruits and vegetables.

  Key Products of Food Irradiation

  • Fresh Fruits and Vegetables: Mango, pomegranate, papaya, litchi, spinach, lettuce, etc.
  • Tubers: Onion and potato.
  • Food Grains, Cereals, and Pulses: Rice, wheat, atta, dal, jowar, maize, etc.
  • Spices: Chilli powder, whole chilli, turmeric, cardamom, pepper, ground mixed spices, etc.
  • Fresh Meat, Seafood, and Poultry: Chicken, fish, shrimp, prawns, crabs, ground meat, etc.

  Mangoes and pomegranates are irradiated for insect disinfestation for quarantine purposes for export to other countries like the USA, Australia, and New Zealand. Parameters include a density of 0.35 gms/cc, dose range of 0.4 to 1 kGy, and an average dose of 0.7 kGy.

  Key Advantages/Benefits of Food Irradiation

  • Shelf Life Extension: From 2-3 days to 3-4 weeks.
  • Energy Savings: Export/storage in chilled conditions (2-4°C) versus frozen (sub-zero) conditions.
  • Improved Quality: Reduction in microbial load and elimination of drip losses.

  Summary of Food Irradiation

  Food irradiation in India is a processing technique that can increase shelf life and decrease spoilage. Foods are subjected to radiation to destroy insects, mold, and microorganisms, without leaving measurable radiation levels in the food. Irradiated foods are labeled per FSSAI guidelines.

  Is It Safe to Eat Irradiated Food?

  For over 30 years, the FDA has assessed the safety of irradiated food and deemed it non-harmful. The safety of irradiated food is also acknowledged by the WHO, CDC, and USDA.

  Amusing Facts about Food Irradiation

  • Food preservation by radiation is used in 55 countries, with China being the greatest consumer.
  • Irradiation as a phytosanitary treatment for food products is mandated in many countries, including the USA, Australia, and several EU members.
  • The USA alone consumed 15,000 metric tonnes of fresh food imports in 2010.
  • Commonly irradiated items include meat products, fresh fruits and vegetables, and tubers.

  Identification of Irradiated Food

• Radiated goods should showcase the global radiation sign per FDA mandate. Labels mention “Treated by irradiation” or “Treated with radiation” alongside the Radura symbol. Bulk items like fruits and vegetables must have a label next to the selling container or be individually labeled.

• It is essential to note that food handling procedures by processors, producers, and consumers are not substitutes for irradiation. Irradiated foods must still be handled, stored, and prepared similarly to non-irradiated foods. If basic food safety guidelines are not followed, organisms may still exist after irradiation.