and reduces drastically the reaction time. Rosenmund-Kuhnhenn method This method is suitable for the determination of iodine value in conjugated systems (ASTM D1541). It has been observed that Wijs/ Hanuš method gives erratic values of IV for some sterols (i.e. cholesterol) and other unsaturated components of insaponifible fraction. The original method uses pyridine dibromide sulfate solution as halogenating agent and an incubation time of 5 min. Other methods Measurement of iodine value with the official method is time-consuming (incubation time of 30 min with Wijs solution) and uses hazardous reagents and solvents. Several non-wet methods have been proposed for determining the iodine value. For example, IV of pure fatty acids and acylglycerols can be theoretically calculated as follows: Accordingly, the IVs of oleic, linoleic, and linolenic acids are respectively 90, 181, and 273. Therefore, the IV of the mixture can be approximated by the following equation : in which and are, respectively, the amount (%) and the iodine value of each individual fatty acid in the mixture. For fats and oils, the IV of the mixture can be calculated from the fatty acid composition profile as determined by gas chromatography (AOAC Cd 1c-85; ISO 3961:2018). However this formula does not take into consideration the olefinic substances in the unsaponifiable fraction. Therefore, this method is not applicable for fish oils as they may contain appreciable amounts of squalene. IV can be also predicted from near-infrared, FTIR and Raman spectroscopy data using the ratio between the intensities of and bands. High resolution proton-NMR provides also fast and reasonably accurate estimation of this parameter. Significance and limitations Although modern analytical methods (such as GC) provides more detailed molecular information including unsaturation degree, the iodine value still widely considered as an important quality parameter for oils and fats. Moreover, IV generally indicates oxidative stability of the fats which directly depend on unsaturation amount. Such a parameter have a direct impact on the processing, the shelf-life and the suitable applications for fat-based products. It is also of a crucial interest for lubricants and fuel industries. In biodiesel specifications, the required limit for IV is 120 g I2/100 g, according to standard EN 14214. IV is extensively used to monitor the industrial processes of hydrogenation and frying. However it must be completed by additional analyses as it does not differentiate cis/trans isomers. G. Knothe (2002) criticized the use of IV as oxidative stability specification for fats