Metal Detectable Brush Bristles – Myth or Miracle

Introduction: Foreign body contamination of foods can be a safety or quality issue, or both. Regardless, if a food is contaminated by a foreign body, the repercussions for the food business can be expensive and damaging. Consequently, the food industry constantly seeks ways to minimize the risk of foreign bodies in food, including the use of metal detection. One source of foreign body contamination is food industry cleaning brushware, where the bristles can snap, be cut, or detach from the brush head and enter the food product. Recently, brushes with 'metal detectable' bristles have been marketed to the food industry as a way of detecting foreign bodies from this source, but do they work?

Purpose: To investigate the durability, functionality and detectability of metal detectable brush bristles

Methods: Durability – metal detectable and plastic bristles were investigated with regard to their break strength and elasticity using a Zwicki 5kN (Zwick Roell). Functionality - the ability of metal detectable bristled brushware to clean a surface of a wet and a dry food soil, was compared with that of a standard plastic bristled brush, using a robotic cleaning rig (Vikan). Metal detectability - metal detectable bristles were investigated with regard to their detectability using a commercial metal detector (Mettler Toledo), with and without the presence of a wet and a dry food product.

Results: Metal detectable bristled products were equally as effective at cleaning as standard drilled and stapled products. PBT bristles were 68% stronger and more than twice as elastic as metal detectable bristles. Metal detectable bristles were not detectable in the presence of a food simulant. 

Significance: Metal detectable bristled brushware offers no advantage with regard to cleaning efficacy and is unlikely to minimize the risk of bristle contamination of food, in fact, it may increase it.