X-ray irradiation can penetrate packaging materials and reach the product.

• A. X-ray irradiation can penetrate 12 inches or more of product and packaging.
• B. It cannot penetrate packaging at all.
• C. It only penetrates metal surfaces.
• D. It is limited to surface treatment of the food.

Answer: (A)

X-ray irradiation uses high-energy photons that can pass through packaging materials and reach the food inside. This penetrating ability lets foods be treated while still sealed in their packaging, which is a key advantage of this method. The depth of penetration depends on the energy of the X-rays and the densities involved, but industrial X-ray systems are designed to penetrate packaging and several inches of product, so 12 inches or more is a realistic, typical capability. That’s why the statement describing penetration through packaging and into the product is the best description. The other ideas—no penetration, penetration only of metal, or being limited to surface treatment—don’t reflect how X-ray irradiation actually works with packaged foods.