**3.2 Physicochemical parameters**

Parameters routinely used to evaluate physicochemical properties of olive oil include density, iodine value, refractive index, saponification value along with unsaponifiable matter. For vegetable oils including olive oil, both density and refraction index depend on the temperature [44]. **Table 1** shows the ranges of the main physicochemical parameters of olive oil. The refractive index at 20°C varies in the range 1.463–1.472. At this same temperature, its density relative to water is between 0.906 and 0.919 [12]. The iodine value is a measure of the total number of double bonds found in an oil sample [1]. Olive oil displays an iodine value between 75 and 94 mg/100 g [17] (**Table 1**). This value is lower than that of argan oil (91–110 g I2/100 g), and cactus seed oil (131.5 ± 0.5 g (I2)/100 g) but higher than that of coconut oil (6.3–10.6 g (I2)/100 g) [13]. High iodine value is associated with the greater number of double bonds and reduced oxidative stability [45]. The saponification value is a measure of the average chain lengths of fatty acids. An oil sample with shorter fatty acids has a high saponification value. Moreover, according to CODEX STAN 33, the saponification value of olive oil varies between 184 and 196 mg (KOH)/g.
