I start drooling when I pass by a bakery. Is that tempting aroma fake?

Whenever I pass by a bakery, I always smell a fragrance that is even more healing in the cold winter. But once I go in, I find that the fragrance is not from the bread.

The topic #bakerysmellfake# became a hot search and sparked heated discussion

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Is the smell of the bakery fake? Why is that? Let's find out today.

01

Where does the smell of bread come from?

The reason why freshly baked bread has a strong aroma is mainly because bacteria, yeast, fermented dough and sugars, etc., produce chemical reactions when heated to produce a series of compounds with caramel, burnt, alcohol and sweet smells [1].

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But within a few hours after being baked, the moisture and alcohol in the bread gradually evaporate, and these compounds will slowly dissipate, and the bread will not smell as fragrant.

During the baking process, the sugars and proteins in the bread react with each other to produce a series of compounds.

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Therefore, in order to attract customers, some bakeries, in addition to baking bread one batch after another, have to rely on a kind of "technology and hard work" called bread aroma .

Bread Aromatherapy Product Review Image Source: Vista Hydrogen Business

Food aroma captures compounds with specific flavors to restore the taste of food. The ingredients of aroma are often a class of complex organic compounds, such as pyrazines, alcohols, aldehydes, ketones and phenolic compounds. If you take out one of them alone, you may think it tastes strange, but after clever mixing, it can become the familiar bread flavor.
Like common perfumes and aromatherapy, food fragrances also dissolve spices in volatile solvents. As the solvent evaporates, the spices will be slowly released and the aroma will be produced.

Smell is a signal obtained by humans through a series of organs and tissues. The human nasal cavity contains about 40 million olfactory cells, each of which has a protruding hair-like structure called "olfactory hairs", which contains a large number of receptors that can generate nerve signals after capturing molecules with odors. After nerve conduction, it is finally processed in our brain and combined into the smell we smell.

02

Why use food aroma?

For other foods that also have a specific flavor and are easy to disperse, merchants may consider using fragrance to attract more customers. In addition to bread, coffee, popcorn and other foods can be "lifelike" imitated by fragrance.

Today, when pre-prepared meals are popular, many diners still pursue the "wok aroma". Therefore, some businesses have launched "wok aroma essence" with the aim of supplementing the olfactory experience.

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In recent years, there are more and more types of food fragrances. So the question is, is the taste of food really that important? The answer is yes, humans are very sensitive to "scent".

Compared to other senses, smell is the most special one: it is the only one that can directly reach the emotional and memory centers of the brain. After perceiving external things, other senses must first pass through the thalamus and then transmit them to the brain, but the sense of smell does not need to take a detour. The signals of olfactory cells can directly reach the amygdala and hippocampus of the brain, which are responsible for processing emotions and memory learning respectively.

Therefore, when we smell a familiar smell again, the amygdala will evoke emotions and the hippocampus will make memories emerge, which creates a close connection between "smell", "emotion" and "memory" [2]. For some Alzheimer's patients, familiar smells can even help them recall the past [3]!

Alzheimer's disease is a common brain disease associated with neurodegeneration.

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Therefore, as a "long-distance" stimulation, just by smelling it, your brain will recall the joy you felt when eating bread and its sweet taste, making you very greedy.

03

Is food aroma harmful to the human body?

During the fermentation process, bread forms a loose and porous structure. This characteristic makes it like a filter that can absorb odors. Therefore, some people use it to absorb odors in the refrigerator.

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Then you can't help but wonder, since bread absorbs flavors, doesn't it also absorb aromas? Can this kind of bread still be eaten?

Although the ingredients of fragrances on the market have not been made public, food fragrances simply capture specific compounds (collectively referred to as "flavors") that can be volatilized in food and captured and recognized by the nose. Even without these compounds, the food will produce exactly the same substances during the processing and production process. This means that as long as it is used at a normal concentration, it will not cause harm to the human body and can be eaten with confidence.

Of course, just like perfume, the concentration that each person can accept is different. This is because the number of olfactory cells and olfactory hairs in each person's nose is different, so the sensitivity to different smells is also different. The same smell may make one person very excited, while another person is indifferent.

Perfume can provide a scent, but if you spray too much, the smell will become pungent.

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So, next time you smell the aroma of a bakery, why not check to see if they have freshly baked bread?

References [1] Li Wenhai. Color and taste of bread [J]. Guangdong: Guangzhou Sugar Company, 1994.

[2] Brann DH, Datta S R. Finding the Brain in the Nose[J]. Annual Review of Neuroscience, 2020, 43: 277-295.

[3] Velayudhan L, Lovestone S. Smell identification test as a treatment response marker in patients with Alzheimer disease receiving donepezil[J]. Journal of clinical psychopharmacology, 2009, 29(4): 387-390.

Author: Wu Erping, member of Shanghai Science Writers Association and Chinese Chemical Society Editor: Bai Ming Acknowledgements: Wu Yang, Ph.D. in Science, Associate Professor, School of Environment and Chemical Engineering, Shanghai University; Jiang Mengping, Ph.D., Center for Excellence in Brain Science and Intelligence Technology (Institute of Neuroscience), Chinese Academy of Sciences, provided scientific guidance for this article.