Black Coffee: Homogeneous or Heterogeneous?

Introduction

Coffee is the second most traded commodity in the world after oil. The demand for coffee is growing steadily, especially in the developed countries. Experts believe that consumption of coffee will continue to increase over the next few years because of its health benefits and convenience factor. The main ingredient in coffee is caffeine which improves mental alertness and helps keep people awake during their working hours. Coffee also contains antioxidants that fight free radicals in body cells and protect them from damage brought about by environmental toxins and other harmful substances found in air pollution.

Coffee is mostly well-known for its black colour and bitter taste.

Coffee is mostly well-known for its black colour and bitter taste. But what exactly accounts for these qualities?

The answer lies in the fact that coffee contains melanoidins, which are formed during roasting. Melanoidins have a number of different functions: they give roasted coffee beans their color and flavor, they help protect against oxidation (which would otherwise degrade the bean), and they also make up part of your body’s immune system!

Both of these characteristics have a scientific explanation, that is, the dissolution of melanoidins formed during roasting.

The dissolution of melanoidins is what gives coffee its characteristic taste and appearance. Melanoidins are formed during roasting, and they dissolve into water during extraction. They dissolve faster at lower temperatures, so cold brew is less likely to over-extract than hot brew when using the same amount of grounds per cup.

Appearance of coffee beans can be changed by changing temperature and quality of water used for extraction.

The appearance of coffee beans can be changed by changing the temperature and quality of water used for extraction.

Coffee beans are composed of a mixture of compounds, including carbohydrates, lipids (fats), proteins and minerals. The compounds that give coffee its distinct smell are called aromatic compounds; they’re what make up around 1% to 2% of roasted coffee beans by weight. These aromatic compounds include things like esters (a compound made up of alcohols), ketones (organic molecules containing carbon double bonded to other elements) and phenols (compounds containing an aromatic ring).

The more heat applied during roasting or brewing processes, the greater amount of volatiles will be released from your brew into your cup!

Melanoidins are compounds responsible for taste and appearance of roasted coffee beans.

Melanoidins are compounds that are created during the roasting process. They’re responsible for the changes in colour and taste of coffee beans, and are produced from sugars, amino acids and proteins.

Melanoidins form when glucose is heated at temperatures between 200°C (392°F) and 300°C (572°F). These reactions result in browning reactions that produce melanoidins with varying degrees of polymerization (DP). The more DP a melanoidin has–that is, how many times its molecules have been linked together–the darker it becomes on your palate.

Melanoidins are produced through roasting process and they are responsible for the changes in colour and taste of coffee beans.

Melanoidins are produced through roasting process and they are responsible for the changes in colour and taste of coffee beans. Melanoidins are formed during roasting process through Maillard reaction, which is a chemical reaction between amino acids or proteins with reducing sugars at high temperatures (above 300C).

The dissolution of melanoidins depends on many factors such as temperature, ratio between coffee to water, quality of water used for extraction etc. It also depends on how long it takes for extraction process to occur (20 minutes or 2 hours).

Melanoidins are compounds responsible for taste and appearance of roasted coffee beans. They are produced through roasting process, which involves heating at high temperatures (about 200-250 ‘C) causing chemical reactions to occur between proteins, sugars and lipids present in green coffee beans. These reactions result in formation of new chemical compounds that give roasted coffee its distinctive flavor, color and aroma.

The dissolution of melanoidins depends on many factors such as temperature, ratio between coffee to water, quality of water used for extraction etc., but also how long it takes for extraction process to occur (20 minutes or 2 hours).

Conclusion

If you want to know more about the science behind black coffee, I encourage you to read our article.