Edible sensors may indicate bacterial contamination By Jane Byrne, 13-Aug-2008

Related topics: Cleaning / Safety / Hygiene, Packaging Materials

Edible nano-sensors made from silk could alert consumers to potential contamination of food produce through a hologram-like indicator embedded in the pack, claim US researchers.

Demand for products that can help processors ensure their goods are safe has grown in the wake of a number of high profile food recalls and scares in the US with researchers looking increasingly to nanotechnology in this regard.

Edible silk lenses as biosensors could be one such means of effectively monitoring the level of dangerous bacteria in food packaging, according to researchers from the School of Engineering at Tufts University in the US.

“For example, at a low cost, we could potentially put a bioactive silk film in every bag of spinach, and it could give the consumer a readout of whether or not E. coli bacteria were in the bag before the food was consumed,” claims David Kaplan, chair of the biomedical engineering department at Tufts.

E. coli

Microbiological safety is a key issue for fruits, vegetables and ready-to-eat prepared vegetable tissues, because all are intended for consumption raw, without further preparation or cooking.

An outbreak of E. coli in September 2006 was traced back to packaged cut spinach originating from California. The outbreak killed three people and sickened more than 200 people across the US.

Biodegradable sensor

Edible nanoparticles can be made of materials that react with the body’s heat or chemistry, such as polymers. Silk optic sensors would have the advantage of the strong, flexible, benign, and biodegradable nature of silk, claim findings from the Tufts University study, published in the American Journal of Chemistry.