**4. Capsaicinoids**

The substances so-called capsaicinoids can be represented, in a simple way, by the binding of a vanillylamide group with fatty acids as a principal characteristic molecular structure, where the fatty chain would have 9–11 carbon atoms. The capsicum fruits synthetizes the capsaicinoids in the placenta-fruit region, close to the tissue adjacent to the seeds. This type of metabolite is unique to *Capsicum* genus. Although little data exist on this compound's biosynthesis, there are reports that the principal two pathways are phenylpropanoid and fatty acid metabolism [16]. The amount of capsaicinoids in the pepper fruit reaches the maximum concentration in about 2 or 3 months of natural fruit development, and after the deceleration initiated by the action of the peroxidase enzymes, the concentration decreases generating secondary compounds. Certainly, the concentration in the fruit varies with the plant species, cultivation conditions, soil, place, seasonality, and so on.

From the point of irritant effect, the capsaicin is the main substance in the midst of capsaicinoids compounds, followed by dihydrocapsaicin. The total capsaicinoids content in the fruits has a typical concentration range of 0.1–1.0% on a dry basis [17],

**163**

**Table 1.**

*Use of Capsaicin for Nonlethal Technology DOI: http://dx.doi.org/10.5772/intechopen.92357*

but it is not a rule and some species have lowest concentration like 0.003% and others have a far high concentration like 1.86% [18]. In general, the capsaicin and dihydrocapsaicin together correspond to ~90% of the total capsaicinoids present in the ready fruit. The typical distribution is 60–70% capsaicin, 20–30% dihydrocapsaicin, 3–7% nordihydrocapsaicin, ~1% homocapsaicin, and ~ 1% homodihydrocapsaicin. However, this is not true in all cases; once, for example, there is evidence that the degree of fruit maturation and incidence of sunlight in the cultivation area, temperatures, and water availability are important factors in the accumulation and proportion of capsaicinoids in the fruit [19]. **Table 1** shows the name, chemical

Unfortunately, there are associations between OC and the molecular capsaicin formula in some pepper spray technicians media, thereby leading to erroneous perception that OC and capsaicin are synonymous with the same substance. Nevertheless, the molecular formula C18H27NO3 is not the OC formula but only the

The biological action of capsaicinoids is complex and multi-targeted mechanisms. The action involves, above all, the activation of peripheral nerve receptors

Capsaicin C18H27NO3 404-86-4

Dihydrocapsaicin C18H29NO3 19408-84-5

Nordihydrocapsaicin C17H27NO3 28789–35-7

Homocapsaicin C19H29NO3 58493-48-4

Homodihydrocapsaicin C19H31NO3 20279-06-5

Nonivamide (PAVA) C17H27NO3 2444-46-4

*Name, chemical structure, molecular formula, and CAS number of the major capsaicinoids.*

**formula**

**CAS**

**Homolog name Chemical structure Molecular** 

structure, and molecular formula of the major capsaicinoids.

capsaicin molecular formula, which is contained in OC.

**4.1 The biological action of capsaicinoids**

### *Use of Capsaicin for Nonlethal Technology DOI: http://dx.doi.org/10.5772/intechopen.92357*

Capsicum

and the region of the plant where it is cultivated—as well as processing way and production. All of these and a lot of other factors contribute to make it difficult to standardize the concentration of irritating agent in pepper spray solutions, thereby leading to a wide range of capsaicin amounts contained in different commercial

Since they produce the desired irritant effect, the capsaicinoids are the most important substances present in the OC used in pepper spray solutions. Other substances such as phenols, acids, alcohols, aldehydes, carotenes, esters, oils, and resins are also present in the OC, but cause a little or no irritant effect compared to capsaicinoids. It should be noted that oils and resin compounds are potentially flammable, and they become undesirable by increasing the flammability of the spray solution. If the spray solution has flammable properties, a jet of flame can be

Furthermore, the OC normally has a strong spice smell, a striking reddish brown color, and has hydrophobic characteristics, thereby requiring organic solvents (or even emulsions) for its complete dissolution. All these features mentioned are

The OC extraction has wide types of processes, and the most simple is the extraction through ground powder fruits. Organic solvents like hexane, ether, alcohols, acetates, and ethylene dichloride are common extraction liquid phase media. In general, the extractions pass by two or three times, removing and replacing with pure solvent at each time. Other simple extractions consist basically to macerate the fruit with olive oil or other seed oils, but the impurity is high and the standardization is far from ideal to use as a raw material for pepper sprays. Modern processes of extractions are advanced Soxhlet extraction, microwave-assisted extraction, supercritical fluid extraction, ultrasound-assisted extraction, and pressurized liquid extraction. All they are more suitable for better-controlled extractions. However, these methods are very expensive and greatly increase the production costs [13]. The concentration of capsaicinoids in OC, in general, shows variations from 1 to 10%, depending on the type of fruit, solvent, process, and so on. Some types of OC capsicum have an approximate concentration range of 3–6% of capsaicinoids, but some Indian suppliers may have OC with 20% of capsaicinoids [15]. Of course, this large amount of concentrations and side substances present in the OC leads to a

difficult standardization of raw material for the pepper spray proposal [12].

plant species, cultivation conditions, soil, place, seasonality, and so on.

The substances so-called capsaicinoids can be represented, in a simple way, by the binding of a vanillylamide group with fatty acids as a principal characteristic molecular structure, where the fatty chain would have 9–11 carbon atoms. The capsicum fruits synthetizes the capsaicinoids in the placenta-fruit region, close to the tissue adjacent to the seeds. This type of metabolite is unique to *Capsicum* genus. Although little data exist on this compound's biosynthesis, there are reports that the principal two pathways are phenylpropanoid and fatty acid metabolism [16]. The amount of capsaicinoids in the pepper fruit reaches the maximum concentration in about 2 or 3 months of natural fruit development, and after the deceleration initiated by the action of the peroxidase enzymes, the concentration decreases generating secondary compounds. Certainly, the concentration in the fruit varies with the

From the point of irritant effect, the capsaicin is the main substance in the midst of capsaicinoids compounds, followed by dihydrocapsaicin. The total capsaicinoids content in the fruits has a typical concentration range of 0.1–1.0% on a dry basis [17],

products and also in separate lots from the same supplier.

produced if there is an ignition source in the path of the spray jet.

undesirable in pepper spray technology.

**162**

**4. Capsaicinoids**

but it is not a rule and some species have lowest concentration like 0.003% and others have a far high concentration like 1.86% [18]. In general, the capsaicin and dihydrocapsaicin together correspond to ~90% of the total capsaicinoids present in the ready fruit. The typical distribution is 60–70% capsaicin, 20–30% dihydrocapsaicin, 3–7% nordihydrocapsaicin, ~1% homocapsaicin, and ~ 1% homodihydrocapsaicin. However, this is not true in all cases; once, for example, there is evidence that the degree of fruit maturation and incidence of sunlight in the cultivation area, temperatures, and water availability are important factors in the accumulation and proportion of capsaicinoids in the fruit [19]. **Table 1** shows the name, chemical structure, and molecular formula of the major capsaicinoids.

Unfortunately, there are associations between OC and the molecular capsaicin formula in some pepper spray technicians media, thereby leading to erroneous perception that OC and capsaicin are synonymous with the same substance. Nevertheless, the molecular formula C18H27NO3 is not the OC formula but only the capsaicin molecular formula, which is contained in OC.
