Introduction 

Have you ever wondered why certain food and beverages smell and taste the way they do? This is due to the magic of aroma compounds, the unsung heroes of the food industry, and the key to unlocking a truly unforgettable product experience.

In this blog post, we'll explore the science behind aroma compounds and how they can take your products to the next level!

Whether you're a food entrepreneur looking to elevate your products, a food scientist seeking a deeper understanding of flavours, or a food business seeking a competitive edge, this blog post is for you.

Terminology

In order to gain a full comprehension of what aroma compounds entail, it is imperative to have a solid foundation of the fundamentals and dispel some common misbeliefs. Initially, it is vital to distinguish between flavour and aroma compounds. For instance, a popular misconception is that flavours are solely detected in the mouth. 

Flavour

Recent studies have found that the flavour of food and beverage is a complex and multifaceted experience. It involves the senses of taste and smell as well as the texture, mouthfeel, temperature and pain perceived by receptors in the mouth. All of these elements come together to create a symphony of sensations when you take a bite or a sip.

Interestingly, olfactory senses, which are activated by aroma compounds, may be responsible for up to 80% of our total flavour experience. In contrast, our taste receptors can only detect five distinct molecules: saltiness, sweetness, sourness, bitterness and umami.

Aroma

The sense of smell is a powerful tool for detecting a wide range of aromas, which are composed of potentially hundreds of different aroma compounds.

Aroma compounds

Aroma compounds are otherwise referred to as volatile compounds. These are a unique category of chemicals that can transform easily from either liquid or solid states to gas at room temperature. This feature makes them especially useful for food and beverage since they can be carried by air and inhaled or exhaled while eating, reaching the aroma receptors located at the back of our nose. Non-volatile substances like proteins, lipids and hydrocolloids are not capable of accomplishing this task.

Volatility

Volatility describes how easily a substance will evaporate (turn into a gas or vapour). 

Flavouring

Flavouring is a ingredient commonly used to enhance the taste and aroma of food and beverage products (e.g. vanilla flavouring). Flavourings can be naturally sourced from plants, vegetables, animals or microbiological origins, or synthesied in a laboratory using complex organic chemistry reactions. 

The legislation governing flavourings follows EU directive 1334/2008, which outlines for instance limits on certain solvents and restricted molecules. It's important to note that different countries may have their own regulations pertaining to flavourings. 

Among the ingredients, a flavouring can contain up to hundreds of aromatic compounds, known as flavouring substances in the legislation.

In future posts, we will dive deeper into the world of flavourings.

Role of aroma compounds in food & beverage

Aroma compounds are molecules that give food and beverage their unique aromas and flavours. Our experience of food and beverage is heavily influenced by these compounds. Only twenty percent of what we perceive as flavour comes from the five basic tastes (sweet, salty, sour, bitter and umami), while the remaining majority is detected through our sense of smell (retronasal detection) which we attribute to aroma compounds. 

Aroma compounds are the essential building blocks of flavours and provide each food and beverage with a distinct flavour profile. In general, the aroma that we associate with an ingredient or product is the result of numerous aroma compounds working in unison. For example, strawberries have hundreds of aroma compounds, while coffee has close to a thousand aroma compounds. 

With this in mind, let’s explore several aroma compounds that may be present in strawberry fruits and how they influence their flavour profiles.

Of the many aroma compounds, only a select few are able to contribute to the characteristic aroma of a given ingredient, which are known as key odorants.

For instance, cooked meat contains a diverse range of aroma compounds, including those that give off roasted, toasted, and fried notes. There are also more unusual aroma compounds, like green, rose, mushroom, and candy floss. However, only a few of these are responsible for the distinct meaty aroma that we all know. 

It's worth noting, though, that not all food and beverages have key odorants. In some cases, a unique aroma may be due to a combination of different aroma compounds, as is the case with strawberries.

Now, let's take a closer look at some of the key odorants that are present in everyday food items.

Although 2-furfuryl mercaptan is a key odorant to the flavour of roasted coffee, it is just one of many compounds responsible for creating a full and satisfying olfactory experience. To craft a well-rounded flavour profile, other aroma compounds are essential, such as milky, nutty, spicy, chocolaty, or caramelic.

Aroma compound volatility

The volatility of aroma compounds refers to their tendency to evaporate from the liquid or solid phase of a food or beverage product into the air. The air full of aroma compounds can be perceived directly through our nose when we smell, which is called orthonasal, or they can arrive at the back of the nose via the throat when we taste, which is known as retronasal.

Factors such as the aroma compounds properties, the composition (including water, alcohol, fat, protein, and carbohydrates), physical state (solid or liquid), pH, and temperature of the food matrix, all affect aroma compound volatility and the way they are perceived by our olfactory receptors.

For instance, smaller aroma compounds with fewer carbon atoms are more volatile and evaporate quickly, lasting only a few seconds when we smell or taste them. Larger aroma compounds with longer molecular structures are less volatile and take longer to evaporate, making them more long-lasting.

The aroma compounds utilised in food and beverage can be categorised into three separate groups based on their volatility, similar to the organisation of fragrances. 
Volatility is an essential factor to consider when developing food and beverage products. To maximise flavour delivery, it is critical to identify which aroma compounds are best suited for your products and processes. For example, fruits and fruit flavourings, such as strawberries, don't typically stand out in baked goods because they contain a lot of top-note aroma compounds that evaporate during baking, resulting in an inferior taste experience. 

In our upcoming blog post, we will delve deeper into these parameters and explore their impact on the release of aromatic compounds from food and beverage products.

Conclusion

A vital part of shaping our food experience is aroma compounds. These compounds are integral in creating the harmony of flavours in food and beverages, from initial aroma to lingering aftertaste.

Understanding the science of aroma compounds and their role as building blocks provides endless possibilities for improving flavour profiles in the food and beverage industry, making it an essential element for entrepreneurs and scientists alike.

Link to related blogs you may enjoy

🔶Mastering Your Palate: How to Use a Flavour Lexicon 

🔶A Journey of Flavours: How a London Food Safari Will Broaden Your Culinary Horizons 

🔶Finding Harmony in Chaos: The Art and Science of Flavour Pairing

References

E. Guichard, Interaction of aroma compounds with food matrices, Flavour Development, Analysis and Perception in Food and Beverages, Series in Food Science, Technology and Nutrition, 2015, Pages 273-295 https://www.sciencedirect.com/science/article/abs/pii/B9781782421030000138 

I.D. Fisk, Aroma release, Flavour Development, Analysis and Perception in Food and Beverages, Series in Food Science, Technology and Nutrition, 2015, Pages 105-123 https://www.sciencedirect.com/book/9781782421030/flavour-development-analysis-and-perception-in-food-and-beverages 

J.K. Parker, Introduction to aroma compounds in foods, Flavour Development, Analysis and Perception in Food and Beverages, Series in Food Science, Technology and Nutrition, 2015, Pages 3-30 https://www.sciencedirect.com/science/article/abs/pii/B9781782421030000011

Peter Coucquyt, Bernard Lahousse, Johan Langenbick, The Art and Science of Foodpairing, 2020

James Briscione, Brooke Parkhurst, The Flavor Matrix: The Art and Science of Pairing Common Ingredients to Create Extraordinary Dishes, 2018

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D. Ulrich, Edelgard Hoberg, Adolf Rapp & Steffen Kecke, Analysis of strawberry flavour – discrimination of aroma types by quantification of volatile compounds, Zeitschrift für Lebensmitteluntersuchung und -Forschung A, volume 205, 1997, pages 218–223 https://link.springer.com/article/10.1007/s002170050154