Food safety is one of the major health issues facing the global economy and is gaining an increasing amount of awareness in the biosensor and food packaging area. It is reported that each year a total of 48 million Americans become sick from contaminated food. Also, an estimated 128,000 of these cases do require hospitalization and 3000 cases result in death. The economic effect of foodborne illnesses and food safety in the US is an estimated burden of 77.7 billion each year.
An efficient detection of microbial contamination, chemicals and toxins in food is the solution to the prevention and recognition of problems related to health and safety. Although, science and technology has recently advanced very sophisticated technologies to detect foodborne threats, including the latest development in nanotechnology, scalable low cost and rapid detection methodologies are still lacking.
The traditional techniques such as culture and colony counting methods, immunology-based and polymerase chain reaction (PCR) based methods unfortunately take up to several hours or even a few days in order to reach a result. Spectrometric methods have also been developed. These methods are rapid, however, require expensive equipment and trained personnel for evaluation. Clearly this is inadequate for certain applications, and recently many researchers are focusing towards the progress of rapid, less costly and more qualitative first response methods.
Novel bio-molecular techniques for food pathogen detection exist and are currently being developed to improve the characteristics of food biosensors. Key attributes include sensitivity, selectivity, and detection speed. The sensor solution has to also be robust and reliable, effective and suitable for in-situ analysis. New technologies show high potential but further research and development is needed in order to have low cost, accurate and rapid detection methods that can be integrated to the food supply chain and thus to improve the overall food safety of the global system.
Food packaging is an essential medium for preserving food quality, minimizing food wastage and reducing preservatives used in food. The packaging also provides the containment protection against physical or chemical damage and gives critical information to the end users the consumers and distributers on the content and its use. Inregration of sensor technology to food packaging will provide the food safety related element that can dramatically increase the total safety of the food supply chain.
The objective of this research was to study the use of diatomaceous earth as a micro-structured media for food safety sensors. The naturally occurring diatomaceous earth consists of fossilized remains of diatoms that are types of algae with a hard-shell structure. Traditionally diatoms have been used in paper based materials, as for example filler in paper making, filtration media, mild abrasive, absorbent material, and a thermal insulator. Perhaps its most famous applocation is for the stabilization material for dynamite. The functionality of gas sensor paper is based on pH sensitive dry that indicates spoilage of meat or fish products by color change. The reaction depends on the chromogenic material. For the detection of ammonia, produced during spoilage, pH indicators such as bromophenol blue or bromocresol purple can be used. The ammonia gas acts as a Lewis-base and induces the color change due to hydrogen relesase. Other gasochromic materials are complexes hance is induced through changes in the ligand field. By adding the diatomaceous earth material as a medium to the sensor paper. we developed a low cost, highly selective and sensitive detection method that can easily be integrated in the paper production process