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The analysis of products within the food and beverage industry (i.e. foodstuffs) is crucial from a quality control perspective to ensure that products have the right nutrient levels, contain all the right constituents, are what they say are (to prevent food forgery) and comply with local and international regulations (if applicable). To ensure this, there are a wide number of food analysis techniques which are used, either in-house, in government facilities or contract research organizations.
Most foodstuffs and beverages need to comply with local regulations and depending on the size and global reach of the manufacturer, the products often need to conform to the local regulations of every country they are being sold in (or regional regulations such as the EU). Aside from conforming to regulations, food analysis methods are put in place to ensure that the quality of the product is up to the desired standard, and they are employed by independent and government agencies to spot if any products are not what they say they are, i.e. food forgery—with the most common examples of food forgery being meats and honey. Additionally, the properties of the food—be it rheological, physiochemical, optical, sensory, flavor, stability, or otherwise—can also be determined using various analytical techniques during the research & development (R&D) phase of a product’s life cycle, and by analyzing the product, it’s properties can be tuned.
Here, were going to look at some of the common food analysis techniques employed within the food and beverage industry. There are so many different aspects that can be analyzed in food that there are many techniques that can be used across all foodstuffs, so the examples below are a few choice examples of some of the more widely used techniques, but it is by no means an exhaustive list.
Gas Chromatography (GC)
Gas chromatography (GC) is a technique which is used on volatile compounds. In a GC instrument, a sample is heated so that it turns into a gas, and the gaseous elements are then analyzed by the detector. It is a method that can be used to separate elements and molecules, as well for identifying what is present in a sample and the purity of a substance. The time it takes for the molecule (the elution time) to get to the detector is used to determine what molecules are present in the sample. In the food and beverage industry, it is widely used for determining the purity and proof (i.e. concentration) of various alcoholic beverages, as the ethanol molecules are one of the few molecules used in the industry that are easily vaporized.
Nuclear Magnetic Resonance (NMR) Spectroscopy
Nuclear magnetic resonance (NMR) spectroscopy is a technique that has gained a lot of use for detecting fraudulent honey. Honey can come from fraudulent origins (to avoid paying extra taxes) and/or they can be diluted with synthetic sugar syrups to lower the quality of the product while increasing the volume that can be sold. Both are common in the honey market.
There are not many techniques which can be used to detect the characteristic ‘origin fingerprints’ in honey once they have been diluted. NMR is a technique which detects molecules under an applied magnetic field and detects how the protons (i.e. hydrogen ions) in the molecule are perturbed in this field. The detection of the protons enables the molecular structure to be built up by how many are coupled to the nearest carbon (or another element in different types of NMR). NMR is also one of a select few techniques that can be used to determine the hard-to-find fingerprints that depict a honey’s origin, as well as for determining whether a honey product has been diluted by cheaper sugar syrups.
Atomic Absorption Spectroscopy (AAS)
Atomic absorption spectroscopy (AAS) is a technique which is used across the food industry to detect the presence of metals in a food or beverage sample. AAS itself is a technique that is widely used in analytical labs to determine the concentration of various chemical elements in a sample by how they absorb light (which are then compared against known standards).
In terms of where it is used, AAS is used in another classic area of food forgery, meats—where it can be used to detect if cheaper types of meat (such as dog or horse meat) are being passed off as beef, lamb, or some other expensive meat found in the supermarket. Other examples of its use in food and drink analysis protocols include the determination of iron concentration in wines (as high concentrations affect the quality), the presence of copper in tea (which arises from the agricultural and fermentation stages), as well the metallic concentrations in beer and fruit juices.
High-Performance Liquid Chromatography (HPLC)
High-performance liquid chromatography (HPLC) is a technique that uses a carrier liquid to carry various molecules through a chromatographic column to a detector. It is a method that is used to separate, identify and determine the concentration of various molecules within a sample. It is a type of liquid chromatography (LC) that is known to be more effective and quicker than other LC techniques. It is essentially the liquid version of GC as both methods use similar principles, but by using liquid and gaseous carrier mediums to carry the molecules of interest, respectively.
In the food industry, HPLC is used to determine the different constituents within a food sample and to see if they are all in the correct ratios—this is again similarly done by elution time to GC. It is a method that is also specifically used to detect different sugars in various food and beverage samples—such as wine and fruit juice—as the elution times of each of the sugars will be different, so HPLC provides an easy way to distinguish between the different sugars and how much of each are in a sample.
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