Detailed Analysis of the components of Fine Coffee beans

Volatile compounds are the primary source of coffee flavor, especially for coffee quality. There are many kinds of volatile snail in coffee, and its existence will affect the aroma quality of coffee. Its primary origin is derived from the non-volatile substances in raw beans which are disconnected or derived from spinning hooks in the process of roasting. The impregnation of thermal differentiation, other spinning hooks or compositions, such as sugars, amino acids, organic acids and phenolic compounds, is not beautiful, forming the unique aroma and flavor of coffee. The factors that affect the volatile components of coffee include: the variety of coffee beans, the weather of cultivation, the premise of soil, the retention of raw beans, the real time of roasting temperature, the status of roasting equipment and so on.

Raw coffee beans do not contain the special aroma of coffee, so they are not eaten directly and must be roasted before a large amount of volatile aroma substances are produced. After roasting, the primary volatile aroma components of raw coffee beans have been analyzed and confirmed that there are at least 660 kinds of volatile aroma components, which is the food with the largest variety of volatile aroma components in all foods and drinks. The aroma produced in the process of roasting, such as hazel, cream and caramel, or with grass, smoke, burning, spice and bitterness, mostly comes from volatile substances. In addition, the difference in roasting level will also affect the flavor characteristics of coffee.

★ adhesive and lignin:

Unmeiguan gum is a substance connected by a variety of polysaccharides, which is mainly composed of galactoic acid polymer, mannose acid and rhamnose, etc., with a content of more than 3%. Lignin is the insoluble residue left by plants after handling sulfuric acid and caustic soda, that is, the so-called coffee fiber, with a content of about 2.4%.

★ nitrogen-containing compounds:

The nitrogenous compounds in raw coffee beans can be divided into plant alkaloids, trigonelline (Trigonelline), nicotinic acid, egg white matter and free amino acids.

★ alkaloids:

Caffeine (Caffeine) is the most important. The content of caffeine in raw coffee beans varies greatly due to differences in varieties. The content of Robusta is higher, the average content is about 2.2% of the dry matter, the content of mineArabica is less, the average content is about 1.2%. In recent years, low-caffeinated coffee beans have been cultivated in Java and C ô te d'Ivoire, with a caffeine content of only 0.2%. Caffeine can be removed in a variety of ways to make all kinds of decaffeinated products. The caffeine content of decaffeinated instant coffee powder is less than 0.3%, and the general commodity is controlled between 0.1% and 0.2%. Caffeine can be said to be the spiritual address of coffee, but also the most controversial issue.

★ volatile substances:

Although caffeine has no odor, it has a remarkable bitter taste. Although some people want to manipulate the same bitterness level of coffee to determine the amount of caffeine, it has not been completely successful, because the bitterness of caffeine accounts for only a small part of the bitterness of coffee, so it has nothing to do with the bitterness of decaffeinated coffee.

After being digested by the human body, caffeine can be quickly received and metabolized and excreted in the urine. The increase of caffeine in human blood depends on the content in the stomach. The most significant psychological effect of caffeine on the human body is the stimulation of the central nervous system, and the dose required for the transformation of brain activity is very high, which is much higher than the normal intake. Other more eye-catching psychological effects are the orientation of blood pressure, cardiovascular and other problems.

★ trigonelline (Trigonelline):

Trigonelline is a colorless crystal with hygroscopicity and excellent ablation in water. It also has a low level of psychological contamination, mainly the central nervous system, bile exudation and intestinal peristalsis.

The direct effect of trigonelline on the quality of coffee is very small, its bitter taste is only 1/4 of caffeine, because its existence is very small, so the mouth snail beak Sik Ying direction is not very big. The content in raw coffee beans varied with different varieties, and the content of Arabica was higher than that of Robusta. Trigonelline will differentiate rapidly in the process of roasting, and its loss rate is about 50% to 80%, which varies according to the difference of roasting temperature and time. Another fenugreek event will differentiate into a variety of compounds, including non-volatile nicotinic acid. , etc., and 29 kinds of volatile substances, among which 9 kinds of aroma substances containing coffee have been identified.

★ nicotinic acid:

The content of nicotinic acid in raw coffee beans is very small, but it increases after roasting, the primary reason is that it comes from fenugreek alkali differentiation and impregnation. However, the study found that under the high temperature of roasting, nicotinic acid will continue to differentiate into volatile chemicals, so the real increase is not much.