Food Biochemistry and Food Processing (2 edition)

BLBS102-c45 BLBS102-Simpson March 21, 2012 14:38 Trim: 276mm X 219mm Printer Name: Yet to Come

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Biosensors for Sensitive Detection of

Agricultural Contaminants, Pathogens

and Food-Borne Toxins

Barry Byrne, Edwina Stack, and Richard O’Kennedy

Introduction

Contaminant Monitoring

Traditional Means of Assessment

Instrumentation-Based Analysis

Biosensors

Biacore

Sensor Surfaces

Assay Configuration

Antibodies

Antibody Production Strategies

Optical Immunosensors for Quality Determination

Electrochemical Sensors

Alternative Biosensor Formats

Pathogens

Bacterial Pathogens

Fungal Pathogens

Toxins

Mycotoxins

Water and Marine Toxins

Legislation

Conclusion

Acknowledgements

Websites of Interest

References

Abstract:Immunosensors permit the rapid and sensitive analysis

of a range of analytes. Here, we provide a critical assessment of how

such formats can be implemented, with emphasis on the detection

of bacterial and fungal pathogens, agricultural contaminants (e.g.

pesticides and herbicides) and toxins.

INTRODUCTION

The monitoring of quality of food destined for human consump-

tion is a key consideration for farmers, the food industry, leg-

islators and, most importantly, for consumers (Karlsson 2004).

Hence, it is an absolute necessity to ensure that any contaminants

that may have a deleterious effect on human health are moni-

tored qualitatively and quantitatively in a sensitive and reliable

manner. For example, herbicides and pesticides are extremely

effective at suppressing the growth of plant and insect popula-

tions on agricultural produce, such as tomatoes and strawberries.

However, the extensive use of such potentially toxic compounds

may compromise the quality of the product, and prolonged ex-

posure may manifest itself as chronic toxicity in human hosts

(Keay and McNeil 1998). Furthermore, bacterial strains such

asSalmonella typhimuriumandListeria monocytogenes,which

are causative agents of salmonellosis and listeriosis, respectively,

can act as opportunistic pathogens and cause death through the

ingestion of contaminated produce. Consequently, the develop-

ment of suitable methods for their rapid detection is an absolute

necessity. Finally, there is also an urgent need to accurately

monitor the distribution of toxins, including fungal (e.g. myco-

toxins) and water-borne toxins (e.g. phycotoxins), which cause

severe illness through the consumption of contaminated food

(e.g. nuts, shellfish meat). In summary, rapid, sensitive and ac-

curate methodologies are essential for the evaluation of product

quality and for satisfying legislative requirements.

CONTAMINANT MONITORING

Traditional Means of Assessment

There are several standard methods that are currently used to

monitor the quality of food. As an example, fruit and vegetable

produce may be inspected by monitoring the colour, gloss, firm-

ness, shape and size of the product, as well as noting the presence

or absence of visible defects. This visual inspection may be per-

formed alongside more invasive methods, including the analysis

of the soluble solid content of the product and determining the

acidity, and is particularly useful for produce such as apples,

pears and berries. The main advantage of such tests relates to

the fact that they may be carried out immediately post-harvest

Food Biochemistry and Food Processing, Second Edition. Edited by Benjamin K. Simpson, Leo M.L. Nollet, Fidel Toldr ́a, Soottawat Benjakul, Gopinadhan Paliyath and Y.H. Hui.

©C2012 John Wiley & Sons, Inc. Published 2012 by John Wiley & Sons, Inc.

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