X-ray inspection systems and metal detectors are used at critical control points (CCPs) to detect foreign objects before the baked goods are shipped. The choice of technology depends on the product, its ingredients, and the type of packaging. For homogeneous products such as pastry cases or croissants, the company relies on metal detection technology. They detect metal contaminants such as ferrous metals (e.g. chromium), non-ferrous metals (e.g. brass and aluminum), as well as magnetic and non-magnetic stainless steel.
For croissants, foreign bodies are detected using a free-fall metal detector integrated into the vertical packaging line. The freshly baked goods fall from above, through the metal detector, are checked and land directly in the sales packaging after inspection. Foreign bodies in products such as the traditional German ring cake, Gugelhupf, as well as most pound cakes, are detected using x-ray inspection systems with a horizontal conveyor belt at a throughput of up to 3,000 units per hour (50 per minute). Contaminated products are removed from the production or packaging line by a pusher reject device.
“In order to best achieve product safety for our customers, we use x-ray inspection systems on the lines where the product or packaging variant requires it,” says Engel. Foil packaging containing aluminum has become significantly more important in baked goods in recent years. It is well suited to baked goods such as pound cakes, as hardly any moisture can escape. The cake does not dry out, is longer lasting and protected from aroma exchange in virtually airtight packaging.
However, aluminum foil poses challenges for foreign body detection. Metal detectors struggle to differentiate between metal contaminants and the metal contained in the packaging. In contrast, x-ray inspection systems are unaffected by aluminum foil packaging and can practically look through the aluminum foil and detect foreign bodies with a high-density difference to the product.
