Commercial Solutions for Reliable Food Contaminant Analysis

By Dr. Priyom Bose, Ph.D.Reviewed by Lily Ramsey, LLM

Several different types of food contaminants, such as toxic metals, veterinary drug residues, pesticides, mycotoxins, organic pollutants, and radionuclides have been identified.¹ Therefore, it is crucial to assess the food quality and safety before consumption. This article focuses on different food assessment solutions to detect food contamination.  

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Importance of Food Contaminant Analysis

Food contamination can occur in many ways. For instance, digitoxin can enter the food chain during production cycles and antibiotics and growth hormones could be introduced during rearing.² The poor handling of dried fruits and nuts could lead to aflatoxin contamination. It must be noted that such contamination could also occur due to poor storage.³

If contaminated foods are consumed, it could seriously affect human health. Many food contaminants could adversely affect the immune system, interfere with hormones, and cause cancer.⁴ Therefore, it is crucial to analyze food products to identify the presence of contaminants. 

Commercial food contaminant analysis solutions have helped food manufacturers gain confidence about food quality and safety. This approach helps protect brands from offering bad quality products that might have negative health consequences.

Reliable Food Contaminant Analysis

Different techniques, such as chromatographic, spectroscopic, and immunoassays, are used to detect food contaminants. Some of the commonly used analytical techniques are discussed below:

Chromatography

Chromatography is a versatile technique that has been employed in various industries. Both gas and liquid chromatographic techniques are used to detect food contaminants. In chemical analysis of food, chromatography helps in the identification and quantification of varied chemicals. After identification, the identified chemical constituents within the food samples are separated. This is an important step because it allows further analysis of the isolated chemicals to determine the effect of a particular chemical component in food.⁵

Gas chromatography (GC) is popularly used in different areas of food assessment, such as the evaluation of nutritional properties, and composition of the food product. This chromatographic technique entails the rapid separation of gases and volatile substances.

Typically, non-volatile chemicals and materials with a high molecular weight are analyzed via liquid chromatography. High-performance liquid chromatography (HPLC) has proved to be instrumental in identifying and quantifying target analytes.⁶ This technique is used to monitor pesticide levels in food products to ensure compliance with government-recommended measurements. HPLC has also been used to detect the presence of antibiotics in food (e.g., meat) as residues from animal treatment.

Spectroscopy

Mass spectrometry (MS) is an analytical technique used to measure the mass-to-charge ratio of molecular ions. For the separation of analytes, either a magnetic or electric field is used post-fragmentation of sample molecules using electron beams.⁷

Adulteration in wine has been an ongoing problem. Therefore, changes in chemical composition in wine due to the addition of contaminants are frequently assessed. To minimize malpractice, wines are assessed regularly. LC-MS and GC-MS are the most reliable food contaminant analysis techniques used in the wine industry.⁸ GC-MS is also commonly used to assess dietary supplements.

Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) spectrometric technique has been used to detect bacterial pathogens in food products, particularly milk, pork, and yogurt. This analytical tool has become very popular owing to its high speed, accuracy, throughput, and automation.⁹

Immunoassays

Enzyme-linked immunosorbent assays (ELISA) are an immune-based analytical tool used to detect microbial contaminants. This analytical technique is based on the binding of known antibodies linked with enzymes with antigens, and subsequent color change. It exploits the antigen’s specificity to antibodies to detect contaminants. 

Commercially available ELISA kits can detect and differentiate Shiga toxin 1 and Shiga toxin in food products contaminated by Shiga toxin-producing E. coli. This technique has also proved to be instrumental in the detection of microbial pathogens in milk.¹⁰

Lateral flow immunoassay (LFIA) acts as an immunosensor that is developed through the integration of biosensors with immunological assay techniques. This technique displayed improved sensitivity and specificity in identifying particular contaminates in food products. A change in the color of the membrane strip (FFIA immunosensor) indicates the presence or absence of the target component.¹¹

There are two types of immunosensors, namely, label-based and label-free, used to detect contaminants. In comparison to label-based, the label-free immunosensor is mostly preferred because of its less processing time and operational simplicity. LFIA uses nanomaterials, such as silver, gold, and carbon, as labels. This technique is used to determine pathogenic contaminants in food products. For instance, E. coli O157 and Salmonella typhi were detected via LFIA in milk samples.

Molecular Techniques

Molecular techniques, such as polymerase chain reaction (PCR), are more sensitive and specific compared to other analytical techniques, such as immunological tests that are used to determine food contaminants.¹² The PCR technique is used to amplify nucleic acids present in the samples and subject them to electrophoresis gel to study the stained bands. This analytical technique is sensitive, efficient, and cost-effective. Real-time PCR is commonly used to monitor pathogens present in samples. For instance, this was used to detect pathogenic Vibrio parahaemolyticus from crude lysate from iced shrimp.¹³

Recent Innovations and Future Trends in Food Contaminant Analysis

As discussed above, various analytical techniques are commercially available to ascertain the authenticity and safety of food products. These analytical strategies help assess the physical, chemical, and microbiological components of food samples.

The advancement in many technologies and methodologies has improved quality control monitoring of food products. For instance, the Bruker IR Biotyper® system enables same-day microbial strain typing, thereby enabling quick quality control assessment.¹⁴

Near-infrared spectroscopy (NIR) developed by BUCHI enabled rapid, eco-friendly, and non-destructive analysis of wet chemistry. This upgraded NIR equipment offers rapid and accurate food analysis. Recently, an efficient extraction technique has been discovered to analyze the presence of 2-chloroethanol and ethylene oxide in food samples.¹⁵

In the future, analytical biosensors with improved selectivity and sensitivity will be required for rapid analysis of food contaminants. Miniaturized sensors, such as microfluidic sensors, with the capacity to analyze bulk samples are required.

There is a need for multiplexed analytical sensors or devices comprising more than one assay /technique for the efficient diagnosis of multiple analytes or contaminants.

Further reading 

• What is Food Safety?
• Amperometric Sensors Assist In Analyzing Food Safety
• Bacteriophages as Biosensors for Food and Water Safety