May 16, 2021 22:00:00

Why is the aroma and taste of chocolate determined by 'microbial fermentation'?

When you think of 'fermented foods,' you can think of yogurt and miso, but in fact, 'fermentation by microorganisms' is important in the chocolate manufacturing process, and the aroma and taste of chocolate derived from

cacao is produced by fermentation. Commentary by Caitlin Clark, a researcher in food science at State University.

Chocolate's secret ingredient is the fermenting microbes that make it taste so good
https://theconversation.com/chocolates-secret-ingredient-is-the-fermenting-microbes-that-make-it-taste-so-good-155552

The process of making chocolate from cacao is as follows.
1: Break the cocoa fruit and take out the seeds inside.
2: The seeds taken out are dried for 3 to 10 days, and then dried in the sun.
3: Roast the dried seeds.
4: Peel the roasted seeds and crush them into a paste.
5: Add sugar or milk powder to the pasty cocoa and mix for another tens of hours.
6: Temper and adjust the temperature.
7: Pour the paste into a mold and harden it.

Fermentation occurs at the stage of drying the cocoa seeds. Yeast breaks down the pulp that sticks to the beans and produces a variety of scented molecules.

In addition, the decomposition of the pulp adds oxygen to the inside of the cacao, reducing the number of yeasts and growing aerobic bacteria that convert the alcohol produced by the yeasts into acetic acid. This bacterium converts yeast-produced alcohol into acetic acid. When this acetic acid soaks into the seeds of cacao, the fat contained in the seeds of cacao aggregates, the protein is decomposed, and the aroma peculiar to chocolate is produced at the roasting stage.

Bacteria have a great effect not only on the aroma of chocolate, but also on the taste. Acetobacter

breaks down astringent polyphenols into a chemical called quinone. This makes cocoa more nutty than just a bitter substance. In addition, the reddish-purple polyphenols in cacao turn into brown quinones, turning chocolate brown.

In addition, when acetic acid evaporates slowly and the sugar contained in cacao is used up, Bacillus subtilis grows. If Bacillus subtilis grows too much due to incorrect temperature control during the chocolate manufacturing process, it will add a rotten cheese-like scent and chocolate production will fail.

The aroma and taste of chocolate is determined by the fermentation of microorganisms, so it is highly dependent on the environment and climate of the cocoa farmer. Chocolate makers produce a wide variety of chocolates by carefully selecting beans according to the aroma and taste they are looking for and adding flavors.