Detecting Food Adulterants using MIR Spectroscopy
Fast, Accurate Analysis of Liquid Samples
With the counterfeiting of goods from foods to fuels now a global problem, the task of authenticating materials such as biodiesel, essential oils and dairy products demands robust, simple to use tools based on sound science. But there’s good news: The challenges of maintaining product integrity have inspired a new generation of counterfeit detection methods with optical sensing technologies at their core. As we’ll explore, these tools are helping to change anti-counterfeiting efforts in fundamental ways.
Mid-infrared spectroscopy is especially useful for identifying adulterants, which often have well defined absorption characteristics within the IR fingerprint region. Also, newer model MIR spectrometers like our Ocean MZ5 spectrometer, which measures liquids, are more compact, portable and simpler to use for screening than alternative technologies including gas chromatography, mass spectrometry and FTIR spectroscopy. This has the effect of bringing the instrument to the sample – and thus, providing screening throughout the supply chain – compared with the disadvantage of more expensive, less immediate lab-based technology
Detecting Food Adulterants
The type and volume of adulterated foods are staggering, ranging from fruit and honey to spices and spirits (Figure 1). Aside from the multimillion dollar losses absorbed by food producers and the fraud perpetrated on consumers, adulterated food exposes the public to the risk of injury and even death. Over the past decade, the most egregious cases — melamine contamination of milk powder in China that sickened thousands of babies, and industrial oil contamination of animal feed used in the European pork market that forced a major recall – have helped spur the development of adulterant detection technologies.
Researchers at leading university food science programs, regulatory agencies and throughout the food industry have invested considerable resources in anti-counterfeiting efforts. The Ocean MZ5 spectrometer (1818-909 cm-1) is a new option for researchers who appreciate the benefits of compact, affordable and real-time measurement systems.
Although conceived primarily as a research tool, the Ocean MZ5 (pictured above) has value beyond the lab, and the core technology is now being developed into fully customized solutions to detect adulterants or monitor quality. Ocean’s MIR technology, ability to engineer complex custom solutions and knowledge of applied spectroscopy are uniquely placed to deliver custom solutions from prototype to mass production. This is especially attractive for food producers and government regulators that until now may not have had access to simple and economical yet still robust adulterant screening options.
Ensuring Milk Integrity using MIR Spectroscopy
The potential impact of mid-IR technology is well illustrated by a recent multi-company partnership to develop an MIR system for determining the quality and integrity of milk in India.
In 2016, Ocean Optics teamed with Pyreos Ltd. (Edinburgh, Scotland), an innovator of infrared sensing technologies including pyroelectric line arrays, to develop new mid-IR solutions. One of the initial Ocean-Pyreos projects is a small, portable solution for detecting the adulteration of milk in India for the German technology company Robert Bosch GmbH.
Robert Bosch is a leading supplier of technology and services for mobility solutions, industrial technology, consumer goods, and energy and building technology. Its largest development center outside corporate headquarters in Germany is in India, where the milk testing is being conducted.
Understanding the Milk Integrity Challenge
India is the world’s largest producer of milk, which is a key part of its agricultural business and a staple food group for India’s 1.3 billion consumers. Producers, regulators and consumers all have a stake in milk quality and integrity.
Milk quality depends on its fat content and composition, and is typically measured using ultra-sonic techniques. Milk integrity relates to authentication and detection of adulterants, which is currently very difficult to do without spectroscopy given the complexity and number of different adulterants that might be used.
India’s dairy supply chain presents a unique challenge. Unlike other parts of the world, India’s dairy production is made up of many small-hold farmers with lower numbers of cows in each herd. These independent farmers take their milk to a local milk collection center, which consolidates the milk supply before transporting it to chilling centers and then to dairy plants.
Although fraud can occur through the supply chain, the local collection point is typically the weakest link. Because the farmers are paid based on the volume and quality of the milk they supply, there is incentive to dilute or adulterate the milk to increase volume or to improve its perceived quality. In fact, some sources estimate that as much as two-thirds of the milk supply is diluted with water and sugars, or adulterated with potentially harmful substances including urea and detergents.
Existing screening options include ultrasonic analyzers and weigh scales, which are affordable but not as powerful and discerning as most spectroscopic techniques.
Meeting a Customer Need
Bosch recognized that sophisticated instrumentation already exists to screen milk for quality and adulterants, but its cost and complexity put it out of reach for India’s local collection centers. Dairy operations further along the chain will invest in such systems, but discovery of adulterated milk at the dairy operation stage can only be addressed by removing large volumes of milk from production. That’s a costly and wasteful outcome.
That’s where Pyreos and Ocean Optics come in. Pyreos offers low-cost mid-IR sensor arrays that are well suited for field based applications with no moving parts, small size, and scalability. Ocean Optics brings to the table its applications know-how, engineering and design expertise, and manufacturing capabilities.
Since 2016, Ocean has worked closely with Pyreos and Bosch to meet the customer’s objectives, drawing on a multi-disciplinary project team to help develop and support the commercialization of the instrument. Although designed for ease of use, the milk testing module is a sophisticated blend of cutting edge optical sensing technology, product design and software development (Figure 3).
Food fraud is big business. By some estimates, 10% of the world’s food supply is adulterated or counterfeited in some fashion, with powders and liquids targeted most frequently. The consequences are significant: higher costs passed on to food producers and consumers; brand damage to food and beverage suppliers; and inadvertent illnesses and death from substandard ingredients and harmful contaminants.
Milk screening is just one example of how Ocean Optics partners with customers to leverage its applied spectral knowledge with advanced sensing techniques such as MIR spectroscopy. For example, our initial testing of adulterants in lavender oil, which is prized for its use as a health product, have also shown the power of MIR. Possibilities for adulterant screening also extend to fuels and pharmaceutical products.
The new MZ5 makes it easier than ever to explore MIR as a potential solution for detecting fraud. But that’s just the beginning. Ocean Optics, steeped in our applied spectroscopy knowledge, engineering and manufacturing capabilities combined with global reach, is uniquely positioned to partner with industry to develop the next generation of solutions.
Together we can take an even bigger bite out of food fraud.
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