Food quality testing techniques are extremely important in the food and beverage manufacturing industries. Before any food product can be sold, it must pass rigorous government and industry standards of health and safety.
Food manufacturers need to be able to verify exactly what their products contain, demonstrate how each ingredient and component of the product affects its nutritional value, and prove their process isn’t altering the products they produce in any way that could be unsafe. Accomplishing all of this requires scientific food quality testing.
Gas Chromatography with Mass Spectrometry and Fourier Transform Infrared Spectrometry are two of the most reliable and highly used food quality testing techniques performed today. This is how both of these techniques work and how they’re applied in food quality assurance:
Gas Chromatography with Mass Spectrometry (GC/MS)
GC/MS is a combination of the gas chromatography and mass spectrometry analytical techniques into a single analytical process. Together, these techniques separate, identify, and quantify all of the individual components of the food product sample being tested – including any possible contaminants.
How GC/MS works
During GC/MS testing, a sample of the product being quality tested is injected into the port of an instrument called a gas chromatograph (GC). The GC heats the sample at a very high temperature until its components volatilize into a gaseous vapor.
Next, the GC introduces an inert gas into the port containing the vapor. This gas propels the vapor into a coiled tube that is coated with an aluminum and silica gel substance called a “stationary phase.” Smaller, more volatile components within the vapor pass through the stationary phase faster than larger and more stable compounds.
As the separated compounds exit the stationary phase, the GC records how long it took them to pass through as each component’s “retention time.”
At this point, the Mass Spectrometry portion of the test begins. Each separated compound flows out of the stationary phase and into the Mass Spectrometer (MS). Upon entering the MS, these compounds reconvene into a single vapor. This vapor interacts with a reagent gas in the MS, triggering a chemical ionization process by which the vapor is broken down into positively-charged ions.
These ions are attracted to an electromagnetic field positioned with the MS’s ion trap. This ion trap only allows ions within a certain range of mass to pass through it. A detector counts each ion as it passes through the trap, providing the MS with the data it needs to produce a “mass spectrum” based on the distribution and sizes of the ions counted.
When analysts have both the retention time of each compound and the mass spectrum of the vapor, they can check each against reference libraries to find matches and therefore identify the compounds in the sample.
What GC/MS is used for in food quality testing
By volatilizing food product samples into vapors, GC/MS can produce extremely accurate and exhaustive analyses of products or ingredients. GC/MS can determine, for example, the nutritional value of a food or beverage by determining its fat and sugar content, along with the vitamins, minerals, and amino acids it contains.
GC/MS is frequently used to determine whether either a food sample or food product such as a container has been tainted. By separating all of the components a sample contains, GC/MS can identify contaminants even in very trace amounts, such as pesticides left behind on harvested foods, preservatives or additives in packaged foods, or even trace toxins that leeched into plastics during manufacturing.
GC/MS testing is also playing a major role in creating synthetic foods.
Fourier Transform Infrared Spectroscopy (FTIR)
FTIR is a form of analysis that measures how a sample absorbs several wavelengths of infrared radiation to determine the precise molecular composition and structure of a sample. It’s frequently used to identify the source of contaminants or packaging defects in food products.
How FTIR works
During FTIR testing, the FTIR device shines a broad spectrum of infrared light onto a sample to measure how the molecules in that sample absorb the light. Bonds between elements absorb different wavelengths of infrared light radiation at unique rates and combinations, making it possible to identify each element and combination of elements comprising the sample.
To successfully bombard the food sample with each spectrum of light very quickly, the FTIR shines a single infrared beam containing all spectrums through a configuration of mirrors called a Michelson interferometer.
The Michelson interferometer spins very quickly, blocking different spectrums of infrared light from the beam one at a time. This rapidly alters the wavelengths of infrared light the sample is exposed to (and absorbs) at any one time, producing a great deal of raw data about the sample’s absorption rates over a short time. This data is called an “interferogram.”
After generating the interferogram, the FTIR device converts the data into a spectrum graph showing the sample’s absorption of each infrared spectrum over time. Analysts can compare this spectrum graph to a reference library to successfully identify all materials contained within the sample, down to a molecular level.
What FTIR is used for in food quality testing
FTIR can identify substances in extreme molecular detail, even if they are only present in a sample in trace amounts. It’s particularly helpful for distinguishing between organic and inorganic compounds such as additives and preservatives.
FTIR is frequently used to authenticate organic and raw materials used in food for labeling and quality assurance. The technique can also be used to determine exactly how a food sample is contaminated, allowing manufacturers to locate where the contamination came from in their process and correct it.
If you need to apply food quality testing techniques to your product or process, the experts at Innovatech are ready to help. Get in touch today.