Coffee cold knowledge | which is sweeter, coffee semi-sugar or monosaccharide? The difference between monosaccharides and semi-sugars turns out to be...

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Carbohydrates in coffee

We put the chemical composition of coffee primarily on carbohydrates, which make up 50% of the weight of raw beans, which you might associate with "sugar", so some people think that coffee beans should be extremely sweet, just like candy. However, most of the carbohydrates in coffee are polysaccharides, not sweet, but after the change, it will stimulate our perception. The most representative carbohydrates in coffee are as follows:

1. Arabinogalactan

two。 Mannan

3. Cellulose

4. Raffinose

5. Stachyose

In terms of the above-mentioned chemical content, there is not much difference between Arabica coffee beans and robusta coffee beans, but robusta coffee beans contain 3% more arabinogalactan than Arabica coffee beans, even logically, you might think that Arabica coffee beans should have a higher content. In addition to being unsweet, some carbohydrates do not play a role in aroma formation during baking, but they undergo dramatic degradation and compression of derivatives that can increase the Body of coffee.

However, raw beans also have 7-10% monosaccharides, some of which are very sweet, but unfortunately, many monosaccharides bind to nitrogen compounds or are destroyed during baking, and if not, even extreme sweeteners do not need to add sugar to their coffee. Monosaccharides include dimers and monomers, in which sucrose is the most important, produced by a combination of glucose and fructose. The content of glucose in raw beans (0.18%) is about 10 times that of fructose (0.02%), but in the baking process, they are all produced by sucrose. Other monomers, including galactose, mannose and arabinogalactan, are indicators of fruit ripening.

Technical relevance and thermal response

Structural polysaccharides, like cellulose, give coffee beans a special structure, and they are relatively stable when roasted, even if they are reduced in the degree of polymerization. At 130C ℃, sucrose has begun to break down to form a dye and decompose into two basic substances (fructose and glucose). As a result, 90% of sucrose disappears at shallow baking, while there is no sucrose at further baking. Galactose, mannose and glucose remain even after baking, while arabinose is the least heat-resistant, with about 60% lost during baking. relatively speaking, the loss of mannose is about 20%, 35%, and 30%, respectively. the loss rate of glucose is as low as 10%. In addition, the loss of mannose is proportional to the roasting degree of coffee beans; the other two (galactose and glucose) are lost rapidly at the initial stage of baking, but the subsequent baking process is stable.

The full text is translated from Italian Coffee tasting Conference-Italian Coffee roasting

Recently, I have been thinking crazily about how to make the sweetness exceed the standard, and have an excellent sense of balance and level. this is really fun.