I am in my third year PhD student in food chemistry.

The question I am always asked is: “What do you actually do?”

In this post I will try to explain what I do. Being a food chemist (or food scientist, in a more general way) means to spend most of the time in the lab, to study the components of food, to improve preparation, processing and storage of food and to check food quality and authenticity.

A food chemist can work in university laboratories (as do I), in food companies (Nestlè) or governmental authorities (e.g. EFSA or BfR). Most of the work nowadays involves quality control, integrity and authenticity analysis. Another topic is to find new ways to produce sufficient nutritious food to feed the population in a sustainable way.

Typical questions we ask ourselves are:

• How can we use natural antioxidants to preserve food?
• Is the origin of this product the one stated on the label or not?
• Is it possible to apply this particular method to test the quality of this product?
• Is this product authentic or has been adulterated with cheaper substances?
• Is it possible to make this particular food packaging environmentally friendly and able to keep the food fresh longer?
• Is this storage protocol good enough, or can it be improved for better food quality?

How do we do it?

Using analytical techniques, which allow us to “see” inside the food. The two techniques I use the most are spectroscopy and spectrometry.

What is spectroscopy?

Through spectroscopy we study the interaction between light and matter. Basically we hit our food samples with visible light (the one that we, human, see), UV light (the one from which we need to protect our eyes and skin) or infrared light (we cannot see it, but we can feel it as heat). The light hit the food samples and the light particles induce a movement in the molecules of the food. Special instruments (called spectroscopes) are able to measure the type and intensity of these tiny movements. This kind of analysis allow food scientists to identify all ingredients of a sample, test its quality and authenticity and detect suspected adulteration.

What is spectrometry?

Spectrometry, more specific mass spectrometry, is a technique in which the food sample is vaporized. That means that it becomes gas. The second step involves ionization of vaporized molecules. The ionization makes all molecules to weight one mass unit more than their weight. All these ionized molecules are accelerated in a channel and in the end they reach the mass spectrometer, which can quantify the number of molecules. Spectrometry is also used to identify ingredients, test food quality and detect suspected adulteration.

What is the difference between spectroscopy and spectrometry?

Both techniques are helpful and used by food chemists. Both have pros and cons.

Spectroscopy is cheap, rapid, no chemical substances are needed for the analysis, easy to perform, applicable by chemists with very little training. But it is not very sensitive.

Spectrometry is a more expensive and time-consuming technique, but it has a high sensitivity, it can detect molecules in the quantity of ppb (part per billion). The ration is the same as detect 1 mg of molecules in 1 ton of sample. But we work with just few grams of sample, so imagine how little the amount of detected molecules actually is.

References:

BfR: https://www.bfr.bund.de/en/home.html

EFSA: https://www.efsa.europa.eu/

Nestlè: https://www.nestlehealthscience.com/

Food Integrity: https://secure.fera.defra.gov.uk/foodintegrity/index.cfm

If you want to apply food science at home, check this book: