How Spectroscopy Is Ensuring Food Safety

By John Oncea, Editor

The impact of ingesting plastics isn’t fully known but, c’mon, it can’t be good. Fortunately, numerous detection methods are being used to keep plastics out of our foods and drinks, including spectroscopy.

Developing reliable and sensitive detection methods is essential for addressing escalating concerns surrounding food products. Being able to catch potential contaminants, pathogens, or other issues before they can cause any damage is crucial for ensuring food safety, as well as addressing public health concerns and maintaining public trust.

Advances in technology have significantly improved detection methods, allowing for greater accuracy, sensitivity, and speed in identifying various substances or issues that might compromise food safety. These methods encompass a range of techniques such as DNA-based testing, immunoassays, and more, all contributing to more reliable and efficient food quality control processes. A third detection method uses spectroscopy and is helping make progress in targeting both microplastic and chemical hazards.

4 Techniques To Keep Food Safe

Spectroscopy is an analytical technique that uses the interaction between matter and electromagnetic radiation to study the properties of matter. In food safety, spectroscopy is used to identify and quantify chemical compounds in food and detect any contaminants or adulterants that may pose a risk to human health. Some common spectroscopic techniques used in food safety include:

• Near-Infrared Spectroscopy (NIRS): As a nondestructive and convenient tool, NIRS has been widely shown to be a promising technique for food safety inspection and control due to its huge advantages of speed, noninvasive measurement, ease of use, and minimal sample preparation requirement, reports PubMed.
• Ultraviolet-Visible (UV-Vis) Spectroscopy: UV-Vis spectroscopy is widely adopted across food and beverage industries and accepted by agencies around the world offers a low-cost means to assess quality, authentication, adulteration, and more, writes Labroots. Food scientists can assess samples with spectrophotometers having general or advanced technologies paired with time-saving accessories and powerful software packages. This powerful, proven technique quickly provides reliable, detailed information about chemical analytes from process samples and final products to ensure composition, consistency, and safety.
• Mass Spectrometry (MS): MS has been considered one of the most suitable techniques, which is widely used in food safety and quality analysis due to its advantages of high sensitivity, selectivity, and throughput, Science Direct writes. Recent developments and improvements in MS allow it to provide more accurate, more precise, and faster analysis of harmful or dangerous compounds in food at very low concentrations. Methods coupling MS with separation techniques, including liquid chromatography (LC-MS) and gas chromatography (GC-MS), have shown great convenience and suitability for food analysis due to their ease of automation and high-throughput capability.
• Nuclear Magnetic Resonance (NMR) Spectroscopy: NMR is the most powerful technique for determining the structure of organic compounds, Current Research in Nutrition and Food Science Journal writes. NMR techniques are used successfully in various food systems for quality control and research. NMR spectroscopy is used to determine the structure of proteins, amino acid profile, carotenoids, organic acids, lipid fractions, and the mobility of the water in foods.

Food Safety North Of The Border

The Canadian Food Inspection Agency (CFIA) Food Foreign Matter Analysis Unit at the Greater Toronto Area (GTA) laboratory uses Fourier transform infrared (FTIR) and Raman spectroscopy, as well as laser-induced breakdown spectroscopy (LIBS) for unknown material identification, food safety investigations and method development research related to food authenticity, according to the Government of Canada.

“Molecules can be identified by how they interact with infrared radiation. FTIR and Raman spectroscopy are complementary technologies based on the absorption and scattering of the middle section of infrared radiation, respectively.

Vibrational spectroscopy includes two methods that generate vibrational motion in chemical bonds of molecules by absorbing low-energy infrared light. These methods enable scientists to obtain molecular fingerprints from various materials. molecular fingerprinting provides a unique structure of the molecule, making it easier to compare similarities and differences between them.

“Material also can be identified by how it cools after being vaporized. LIBS is a type of emission spectroscopy that analyses plasma radiation. LIBS generates plasma by vaporizing a micrometer-sized portion of the sample surface at an extremely high temperature.”

When a high-energy laser pulse is fired at a material, it creates a short-lived, high-temperature plasma, similar to the ones seen on the sun's surface. The light given off as the plasma cools down is gathered by spectrophotometers, which produce a unique fingerprint of the atoms and ions present in the plasma. This process is called Laser-Induced Breakdown Spectroscopy (LIBS) and is considered to be one of the most efficient ways to quickly analyze the atomic composition of gases, liquids, and solids. LIBS has become so popular that it is now used as a key instrument on the Mars rover to study the chemical makeup of rocks and minerals on another planet.

Fluorescence Spectroscopy Offers Another Opportunity

Spectroscopic methods involve measuring the interaction of light with matter in terms of its wavelength dependence. This interaction could either be the amount of light absorbed by a sample or the diffuse reflection of light off a sample. Spectroscopy is a valuable tool for measuring a wide variety of liquids, solids, and gases. By incorporating certain types of measurement heads and probes, it is possible to measure samples in line without destroying any of the products and delaying the process.

“Each compound has a unique fingerprint or molecular composition and arrangement of atoms,” writes HORIBA. Each chemical, therefore, will interact with light at different wavelengths, making identification of these molecules in a non-destructive way.”

The dairy industry utilizes NIRS to monitor the sugar, fat, and water content of its products. This technology not only enables quality control but also helps detect any discrepancies between the predetermined standards. In the case of a contaminated sample or any deviations from the norm, spectroscopy can trigger a warning signal to alert the industry of potential issues.

“Food scientists also develop new foods. Each one has problems that must be solved. Fluorescence spectroscopy plays a role,” HORIBA writes. “The challenge is figuring out how to manufacture the food item and keep it safe.”

Why It Matters

According to a study led by Australia's national science agency, CSIRO, plastics and their additives are present at a range of concentrations not only in fish but in many products including meat, chicken, rice, water, takeout food and drink, and even fresh produce.

The study, The measurement of food safety and security risks associated with micro- and nanoplastic pollution, analyzes academic literature on microplastics from a food safety and food security risk viewpoint, building on past studies that primarily tracked plastics in fish. Dr. Jordi Nelis, CSIRO analytical chemist, food safety specialist, and lead author of the paper, said these plastics enter the human food chain through numerous pathways, such as ingestion as shown in the fish studies, but one of the main ways is through food processing and packaging

“Fresh food for example can be plastic free when it’s picked or caught but contain plastics by the time it’s been handled, packaged, and makes its way to us,” Nelis said. “Machinery, cutting boards, and plastic wrapping can all deposit micro and nanoplastics onto the food that we then consume. This study highlights the need to understand what plastic could end up in food to manage food safety and security.”

“While the impact of ingesting plastics on human health is not yet fully understood, there is already some research that suggests it could be harmful,” writes the BBC. “Studies show that chemicals added during the production of plastics can disrupt the endocrine system and the hormones that regulate our growth and development.”

Chemicals that are present in plastic have been associated with various health issues such as cancer, heart disease, and impaired fetal development. The research conducted by experts at the University of Hull, U.K., suggests that excessive consumption of microplastics can cause damage to cells and lead to inflammation and allergic reactions.