Food and Beverage Analysis

Chemical fingerprinting can provide evidence for quality differences resulting from botanical and geographical origins of primary food ingredients, post-harvest practices, production processes (such as traditional versus industrial processes), and the shelf-life evolution of finished products. This article discusses the strategic role and potential of comprehensive two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS) and pattern recognition using template matching for data processing to unravel the quality traits of high-quality food products. Practical examples dealing with high-quality cocoa and extra-virgin olive oil are described.

Chemical fingerprinting can provide evidence for quality differences resulting from botanical and geographical origins of primary food ingredients, post-harvest practices, production processes (such as traditional versus industrial processes), and the shelf-life evolution of finished products. This article discusses the strategic role and potential of comprehensive two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS) and pattern recognition using template matching for data processing to unravel the quality traits of high-quality food products. Practical examples dealing with high-quality cocoa and extra-virgin olive oil are described.

In the early days of dioxin analysis, applied methods were laboratory- and time-consuming. Only GC–HRMS, which is complicated, was used. Nowadays, GC–MS/MS is suitable for control proposes. Using GC–MS/MS means that solvent consumption for sample preparation can be reduced by a factor of 10 and the purity of the obtained fraction can be enhanced, indicating that GC–MS/MS is appropriate for dioxin analysis.

Ten years since its official definition, foodomics continues to expand the scientific knowledge of food and nutrition while resolving many analytical challenges along the way. LCGC Europe spoke to Alejandro Cifuentes from the Institute of Food Science Research, in Madrid, Spain, about his current foodomics research projects, the overall state of the field, and the future of foodomics.

Traditional sample preparation method development can often be laborious and costly. Understanding the underlying concepts of the technique can help food and environmental laboratories develop methods in notoriously complex matrices, faster, more efficiently, and provide better chromatography. With the presence of many unique matrices and analytes, methods such as QuEChERS, supported liquid extraction (SLE), or solid-phase extraction (SPE) provide the necessary adaptability for many types of extractions. With customizable methods to work with unique matrices and with the addition of automation, extractions can be improved to save time and provide consistent recoveries.

This method showed excellent precision and accuracy for the 12 FDA regulated mycotoxins that were evaluated during a validation study that covered a variety of matrices.

Pickering Laboratories developed an analytical method to comply with all the chromatographic requirements of Commission Regulation (EC) No 152-2009.

When analytical chemists apply green chemistry approaches, which seek to minimize negative environmental effects, an important area of focus is reducing the consumption of toxic solvents, such as those used in extraction steps in sample preparation. Developing and testing greener extraction processes for food analysis is a major focus of Elena Ibáñez, a research professor at the Institute of Food Science Research (CIAL-CSIC) in Madrid, Spain.

Analytical separation techniques based on the differential migration velocities of analytes under the action of an electric field are gaining increasing acceptance for the analysis of phenolic compounds in edible and medicinal plants and in plant-derived food products. In Part 2 of this review article the authors discuss the fundamental principles and practical aspects of electromigration techniques, including capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), and capillary electrochromatography (CEC). The development of two-dimensional systems, performed by coupling either liquid chromatography (LC) with an electromigration technique or two electromigration techniques, operated under different separation mechanisms, is also discussed.

Carcinogen-containing compounds can develop through some manufacturing processes, such as in the malting process for beer. It is critical to analyze the nitrosamine content in any consumed products as well as monitor the final product. Thermal energy analysis (TEA) is able to quickly identify and analyze N-Nitro, N-nitroso, and nitrogen-containing compounds. This article describes the importance of monitoring these compounds.

This article highlights three events that require new method development to meet various detection needs, ranging from the detection of pesticides such as fipronil and glyphosate, to the detection and quantification of fat-soluble vitamins.

Researchers from the University of Gothenburg, in Gothenburg, Sweden, have investigated whether plasma amino acid levels differed among children with celiac disease using liquid chromatography–mass spectrometry (LC–MS) (1).

The Column spoke to Ricardo Lopez from the University of Zaragoza, in Spain, about his work characterizing the composition of the vapours from wine during consumption using an automated gas chromatography–mass spectrometry (GC–MS) technique.

Food analysis is often handled less thoroughly than pharmaceutical analysis because of the smaller life-threatening risk expected from foodstuffs. However, food analysis is still a major focus for chromatographers from a scientific and an analytical point of view. Adoption of modern “in‑silico” techniques, such as chromatographic modelling, offer analysts new possibilities for method development.

Synthetic azo- and non-azo dyes were once commonly used as food colourings in many countries. Food safety regulators in Europe, the U.S, and other countries have now banned the use of these synthetic dyes in food because of their potential genotoxic and carcinogenic effects. In some countries, however, these dyes are still being used, especially in spices. There are currently no published legal limits for these illegal food dyes, but any detectable amount is deemed unacceptable. Thus, any analytical method used to test foods for these illegal dyes must be highly sensitive. Conventional methods are only able to provide limits of quantitation (LOQs) of 10–1000 ppb for these illegal food dyes. A reversed-phase ultrahigh-pressure liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) method has been developed that reliably achieves LOQs that are three-to-four orders of magnitude lower than conventional methods while also providing improved accuracy and reproducibility.

The durian fruit is notorious for its unpalatable aroma, and yet the fruit is incredibly popular throughout Southeast Asia and amongst travellers. Holding the title of “the world’s smelliest fruit” attracts attention including that of Martin Steinhaus from the Aroma Research Group at the Deutsche Forschungsanstalt für Lebensmittelchemie (German Research Center for Food Chemistry). He spoke to The Column about his group’s research into the compounds responsible for the fruit’s uniquely unpleasant aroma.

Polyphenols are a well-known group of antioxidants widely diffused as secondary metabolites in plants, vegetables, and fruit. The Column spoke to Nicola Marchetti from the Department of Chemistry and Pharmaceutical Sciences at the University of Ferrara in Ferrara, Italy, about his research into the characterization of polyphenols in red chicory using high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS).

Monitoring lipid oxidation during the shelf life of lipid-containing food emulsions, such as mayonnaise, is challenging. It is, however, essential for the development of improved, consumer-preferred products. Determining the nonvolatile lipid oxidation products (NONVOLLOPS), the precursor compounds for rancidity, is required to determine the effectiveness of product stabilization technologies. A method based on normal-phase liquid chromatography with atmospheric pressure photo ionization-mass spectrometry (LC–APPI-MS) was developed for this purpose. The inclusion of a size-exclusion chromatography (SEC) step was needed to remove interfering diacylglycerides and free fatty acids from the samples. The combined SEC and normal-phase LC–APPI-MS method allowed the identification of a wide range of oxidized species including hydroperoxides, oxo-2½ glycerides, epoxides, and other oxidized species. The method was found to be more suitable for the analysis of large sample sets.

There is a growing interest in polyphenols because of their noticeable antioxidant properties and their potential contribution to the defence against oxidative stress and protection against cardiovascular diseases and cancers. Oscar Núñez from the Department of Chemical Engineering and Analytical Chemistry at the University of Barcelona in Barcelona, Spain, has been working since 2010 in the analysis of polyphenols by capillary electrophoresis (CE), liquid chromatography (LC), mass spectrometry (MS), and chemometric techniques to achieve the characterization, classification, and authentication of natural products in the prevention of frauds. He recently spoke to The Column about this research.

Adulteration is a significant problem for the olive oil industry because of the product’s high value. With the demand for olive oil expected to rise significantly, this problem is set to increase. Reliable and accurate determinations of olive oil adulteration are therefore required to maintain product integrity. This article introduces a principle component analysis‑based approach that uses data obtained by high performance liquid chromatography (HPLC)-charged aerosol detection (CAD) to determine extra virgin olive oil adulteration by common vegetable oil adulterants. Using only sample dilution and analysis, the method could be used to assess olive oil quality relative to pomace oil.