Food Adulteration and How It Is Revealed by Analytical Chemistry

Food adulteration is a phenomenon with a long history that has gained increasing importance in recent years due to the globalization of food supply chains and strong economic pressures. Whether it involves diluting olive oil with cheaper oils, adding sugar to honey, or the hidden use of substitutes in protein supplements, the result is a loss of consumer trust and, in some cases, a potential risk to health. Analytical chemistry plays a key role in this area by providing methods and technologies capable of identifying and quantifying target compounds as well as unwanted impurities in a wide range of food matrices.

Watrex: Food Adulteration and How It Is Revealed by Analytical Chemistry

The Role of Chromatography in Forensic Food Analysis

Chromatography, particularly liquid chromatography (HPLC), is one of the most effective analytical tools for separating complex mixtures of molecules. It enables:

• qualitative identification of individual components in a sample,
• quantitative determination of their concentrations,
• detection of impurities and unexpected components that may indicate
  adulteration.

In practice, HPLC is often combined with various types of detectors (UV/VIS, DAD, refractive index detectors) or with other techniques (e.g., mass spectrometry) to increase selectivity and sensitivity.

Isocratic vs. Gradient Elution

In the analysis of food samples, chromatographic methods are selected according to the analytical goal:

• Isocratic HPLC uses a constant mobile phase composition throughout the analysis. It is simple, robust, and ideal for routine determinations of well-defined target analytes (e.g., sugars or vitamins).
• Gradient HPLC changes the mobile phase composition during separation, enabling better resolution of complex mixtures with a wide range of polarities (e.g., peptides or phenolic compounds).

Gradient methods are particularly useful when analytes have very different properties and high separation efficiency is required.

Watrex Praha and the Contribution of Modern Systems to Food Analysis

Watrex Praha, s.r.o. is one of the leading Czech manufacturers and distributors of liquid chromatography systems and instruments, with a long tradition dating back to 1990. The company has successfully transformed from a distributor into a manufacturer of its own HPLC and related technologies, focusing on modular, robust systems suitable even for demanding analytical tasks.

Their Streamline™ product line includes several HPLC system concepts suitable for food analysis:

• Isocratic HPLC system – a simple yet precise configuration with a single pump, column thermostat, and UV/VIS detector; suitable for routine determination of known analytes (e.g., basic carbohydrates, food additives).
• Binary gradient HPLC system – equipped with two pumps enabling mobile phase gradient formation, which enhances separation performance for complex mixtures
  (e.g., phenolic profiles of wine, components of aromatic extracts).
• GPC/SEC system (Gel Permeation / Size Exclusion Chromatography) – a specialized solution for the determination of macromolecules and polymers, also relevant for the analysis of high-molecular-weight components in foods (e.g., polysaccharides).

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Thanks to the modular nature of these systems, analysts can easily adapt the configuration to a specific analytical problem, from simple routine analyses to complex characterization of food samples.

Practical Examples of Adulteration Revealed by HPLC

• Detection of olive oil dilution: HPLC can separate and quantify characteristic triacylglycerols and fatty acids; unusual patterns indicate the presence of cheaper oils.
• Estimation of sugar addition in honey: Isocratic HPLC with a refractive index detector can determine sugar profiles (glucose, fructose, sucrose), revealing dilution or the addition of sugar syrups.
• Identification of aromatic adulterants in wine: Gradient HPLC with a PDA detector can reveal phenolic and aromatic profiles that are altered by the addition of synthetic compounds.

Conclusion

Food adulteration remains a current issue that requires reliable and sensitive analytical methods. Liquid chromatography, and in particular modern HPLC systems, represent one of the most powerful tools for detecting unwanted additives, impurities, and unexpected components in complex food samples. Manufacturers such as Watrex Praha provide flexible chromatographic platforms covering a wide range of analytical tasks from simple isocratic to advanced gradient and GPC/SEC applications thereby supporting analysts in ensuring food quality and consumer protection.

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