*6.3. Squalenes*

Squalenes are polyunsaturated acyclic hydrocarbons with a triterpenoid lipophilic structure, similar to the vitamin E structure, and they contribute to the oxidation stability of vegetable oils because they prevent peroxidation of fats acting mainly against peroxyl radicals.

Squalene acts as a biosynthetic precursor to all steroids in plants and animals. However, Cherif et al. [90] detected a dramatic decrease in sterols at the 10–12th maturation week that suggested there was the absence of the synthesis of novo sterols from squalene which was maintained an enzymatic activity until the end of maturity. Squalene has important beneficial e ffects on health, such as decreasing the risk for various cancers and reducing serum cholesterol levels [91]. Squalene contents in almond oils ranged from 37.9 to 114.2 μg/g of oil (Table 4).


**Table 4.** Minor compounds: phytosterols, terpenic alcohols, squalene, aliphatic alcohols and tocopherols.


**Table 4.** *Cont.*

In parenthesis: samples origin country/region; in brackets: source of variability studied. [a] variety; [b] environment/crop year; [c] extraction method. [94]: (Brazil); [92]: (Iran); [85]: (Sweden); [30]: (Argentina) [a,b]; [93]: (Turkey) [c]; [95]: [c]; [87]: (Turkey) [c]; [96]: (USA); [11]: (Spain) [a,b]; [12]: (Spain) [c]; [90]: (Tunisia) [a,b].
