**2. Chemical constituents**

The main constituents of coffee are caffeine, tannin, fixed oil, carbohydrates, and proteins. It contains 2–3% caffeine, 3–5% tannins, 13% proteins, and 10–15% fixed oils. In the seeds, caffeine is present as a salt of chlorogenic acid (CGA). Also it contains oil and wax [2].

The following sections will be discussed in detail after acceptance of this short proposal:

• This article will deal on the types of carbohydrate, protein, lipids, and other chemical constituents in detail.

and play a vital role in the formation of the coffee flavor. The various constituents

Soluble carbohydrates Monosaccharides Fructose, glucose, galactose, arabinose (traces)

Insoluble polysaccharides

Polysaccharides Polymers of galactose, mannose, arabinose, glucose

Cellulose Acids and phenols Volatile acids

Lignin Lipids Wax

Proteins

Trigonelline Minerals

Hemicelluloses Polymers of galactose, arabinose, mannose

Nonvolatile aliphatic acids Citric acid, malic acid, quinic acid Chlorogenic acids Mono-, dicaffeoyl- and feruloylquinic acid

Oil Main fatty acids: N Compounds Free amino acids Main amino acids: Glu, Asp, Asp-NH2

Caffeine Traces of theobromine and theophylline

Most of the carbohydrates present, such as cellulose and polysaccharides

Linoleic acid is the predominant fatty acid, followed by palmitic acid.

The lipid fraction appears to be very stable, and its composition is given below.

The volatile acids include formic acids and acetic acids, while nonvolatile acids include lactic, tartaric, pyruvic, and citric acid. Minor constituents include higher fatty acids and malonic, succinic, glutaric, and malic acids. The degradation products of citric acid are itaconic (I), citraconic (II), and mesaconic acids (III), while

consisting of mannose, galactose, and arabinose, are insoluble.

fumaric and maleic acids are degraded products of malic acid:

along with components of coffee are shown in **Table 1**.

Oligosaccharides Sucrose, raffinose, stachyose

**Constituent Components**

*A Detail Chemistry of Coffee and Its Analysis DOI: http://dx.doi.org/10.5772/intechopen.91725*

**3. Carbohydrates**

*Constituents along with components of coffee.*

Lipid composition. Triacylglycerols. Diterpene esters. Diterpenes. Triterpene esters. Triterpenes (sterols). Unidentified compounds.

**4. Lipids**

**Table 1.**

**5. Acids**

**81**

• This article will review on various analytical methods for the estimation of constituents present in coffee.

Coffee is often used as antioxidants, but more importantly coffee is a good source of chromium and magnesium that assist in controlling blood sugar by ensuring proper usage of insulin.

The main chemical ingredients in coffee beans are given below:


The carbohydrate content of green and roasted coffee (Santos) was identified and measured. Green coffee contained about 6–7% of sucrose as soluble sugars and low amount of glucose. The soluble sugars of roasted coffee were sucrose, fructose, and glucose. The experiment was also carried out for the isolation of holocellulose fractions of green and roasted coffee.

The holocellulose of green coffee was hydrolyzed by a novel method consisting of anhydrous sulfuric acid and 10% potassium insoluble hydroxide, which was partially solubilized on roasting and results in the following ratio of sugars:

1 L-arabinose/2D-galactose/2D-glucose/6D-mannose. Out of these sugars, the arabinose was easily acid-hydrolyzed. Other coffee constituent analyzed and determined were caffeine, trigonelline, caffeic acid, chlorogenic acid, isochlorogenic acid, and the 10 amino acids. The free amino acids disappeared in roasting. An analytical method was developed for evaluating caffeine on chromatograms [3].

In coffee pulp, condensed tannins are the major phenolic compounds, while in the seeds, phenolic compounds exist primarily as a family of esters formed between hydroxycinnamic acids and quinic acid, collectively recognized as chlorogenic acids (CGA). Green coffee seeds contain up to 14% CGA, which are present in high concentrations and have a greater influence for determining the quality of coffee
