Food Authentication: Better Safety, More Powerful Technology

Food fraud—a collective term used to encompass the deliberate and intentional substitution, addition, tampering, or misrepresentation of food, food ingredients, or food packaging or false or misleading statements made about a product for economic gain—significantly impacts public health and the global economy (Spink and Moyer 2011, Moyer et al. 2017).Several food fraud cases over the past decade or so emphasize the significance of this topic. One high-profile example is the melamine crisis that impacted thousands of infants in 2008 and 2009. Then there was the 2012 Czech vodka laced with methanol that led to the deaths of more than 50 people. The European horse meat scandal of 2013 revealed—and confirmed through DNA analysis—that in some cases, nearly 100% of the beef patty meat was actually horse meat. The olive oil fraud represents a decade of disaster (2004–2014) that markedly affected prices. In this case, refined olive oil was substituted for extra virgin olive oil, which reflected poor farming, corrupt trade, complacent regulators, fraudulent science, and false advertising. Other global cases included the intentional adulteration of cumin with peanut and almond shells in 2015 and 2016 and oregano that was adulterated with several varieties of leaves from olive, sumac, myrtle, and other plant materials from 2015 through 2017.

A 2017 overview of food fraud data gathered by USP (USP Food Fraud Database 2.0, which is now owned by Decernis) indicates the greatest number of incidence reports (100 to nearly 600) are associated with dairy ingredients, seafood products, meat and poultry products, olive oil, herbs and spices, alcoholic beverages, honey, fruit and vegetable juices, grains, coffee, and cheeses.

The Global Food Safety Initiative and the Food Safety Modernization Act provide clear action items to prevent and detect intentional adulteration of the food supply (GFSI 2018, FSMA 2015). There have been several other guidances and compendial standards intended to mitigate food fraud via a thorough hazard analysis and hazard identification of substances in foods, even if the substance occurs naturally or was unintentionally introduced and also, of course, if it was intentionally added to a food for the purposes of economic gain.

As consumers demand foods that are safe, nutritious, accessible, and affordable, there has emerged a rapidly growing field intended to assure the quality and safety of foods. This field involves an array of analytical techniques encompassed in food authentication (Danezis et al. 2016, Szpylka 2018).

At its core, food authentication is the process with which a food is verified as complying with its label description. This is safety personified, and with increasing consumerism and public awareness of food adulteration, food authentication can be considered an established yet rapidly growing field. Multiple analytical breakthroughs and novel techniques have revolutionized the field as a legitimate scientific specialty.

Toxicants and xenobiotics (compounds that are foreign to an organism) can be detected before an item enters the human food chain by applying molecular methods. DNA barcoding, polymerase chain reaction, and related targeted molecular methods for food authentication detect microbial contaminants across the plant and animal kingdoms. Many of these techniques focus on specific signatures such as ribosomal RNA, cytochrome c oxidase I, or maturase K genes (Haiminen et al. 2019).

Potential toxicants can be detected by infrared spectroscopy, gas chromatography, Raman spectrometry, mass spectrometry, and nuclear magnetic resonance spectroscopy, all of which can be used individually and collectively in various protocols to measure small amounts of specific compounds in a sample, which are then used as markers of authenticity. Because spectral imaging (such as VIS/NIR hyperspectral imaging, FT-IR imaging, and Raman imaging) could capture large image data within spectral ranges, imaging spectroscopy is acknowledged as an effective means to meet the speed demand in the food industry (Su et al. 2018).

Stable isotope ratios deserve a mention; this technology has been used for years to reflect geographical variation and has been widely used to trace the origin of various agricultural products. The isotopic composition of hydrogen and oxygen of soil water is highly dependent on the isotopic composition of local precipitation, which in turn is dependent on geographical location. Hydrogen- and oxygen-stable isotope analyses in plants reflect the isotopic composition of ground water and transpiration enrichment. For example, a recent assessment of pure orange juices from Asia, Australia, and New Zealand indicated various geographical regions have distinctive values of the isotope oxygen-18. This approach may be useful in tracing and tracking fruits and vegetables (GNS Science Te Pū Ao 2020). Taking a cue from Tox 21, high-throughput nucleic acid sequencing combined with robust bioinformatic analysis has the potential to replace or augment current tests for verifying food ingredient composition by detecting contaminants without prior assumptions of the expected content. In addition to the food matrix composition, metagenomic sequencing importantly yields a snapshot of the microbial content and possible pathogens (Yang et al. 2016).

Another emerging issue in this space is religious authentication of food. The Muslim community may be concerned about halal foodstuffs; food or drink that is permitted for consumption must be confirmed by the Islamic law as revealed in the Koran or the tradition of prophet Muhammad (hadith). At present, the halal industry is seen as one of the fastest-growing consumer platforms in the world, estimated to be worth over a trillion dollars. Though halal products are becoming more popular, incorrect halal certification of food products has become a common scenario in food markets. Due to this research on halal, protein-based detection algorithms have arisen (El-Hack et al. 2018). In the Jewish dimension, authentication of kosher ingredients has driven the development of validated and reliable identification of lipid biomarkers that can assure a food item’s kosher status (Rohman and Fadzillah 2018).

As the food industry, regulatory agencies, and consumers call for foods that are safer and more nutritious, new analytical techniques, regulatory controls, and the global sharing of information should sharply curtail food fraudster activities (Hong et al. 2017, Cattini 2016).