Iodine value means the g value of halogen which adhere to g of methods such as hanus method and wijs method for iodine value. Estimation of iodine value of fats and oils theory. Iodine value is a useful parameter in studying oxidative rancidity of oils since higher the unsaturation the greater the possibility of the oils to go rancid. The amount of iodine absorbed in milligrams by 1g of carbon using test conditions listed herein is called the iodine number. Determination of iodine numbers of edible oils wiley online library. Feb 06, 2012 it must be noted that a high iv value in oil consists of a greater number of double bonds than a low iv oil. Determination of iodine number is used for the assessment of its purity. The iodine value is the number which expresses in grams the quantity of halogen, calculated as iodine, which is absorbed by 100 g of the substance under the described conditions. Iodine value of sunflower oil the determination of iodine value is of great importance in finding the proportion of adulteration in oils this gives an idea of its drying character. Saturated fatty acids will not give the halogenation reaction.
Iodine value refers to the percentage of iodine absorbed by a substance such as a fat or oil 1. Method a iodine monochloride method or wijs method. Simple spectrophotometric method for determination of iodine value of vegetable oils thidarat kruatian a and kritsana jitmaneea,b,c a department of chemistry and center of excellence for innovation in chemistry, faculty of science, chiang mai university, chiang mai 50200, thailand. The two chemical parameters determined are very essential in understanding the potentials of an oil or fat, especially in the soap making industry.
Determination of the iodine value of oils and fats oxford. It is an indication of a fats it is an indication of a fats potential to be oxidized as it measures the reaction of iodine with the double bonds of unsaturated fatty acids 2. The determination of peroxide value is highly empirical. Physicochemical analysis and fatty acid composition of oil. Quantitative determination of the iodine values of. The result is expressed as g of iodine i2 per 100 g of sample. For the determination of the iodine number of oleic and ricin oleic acids both the hanus and the rosenmund methods give the same value which is very near the theoretical. In case of divergent results between two laboratories, the two parts must carry out a second series of analyses strictly applying common critical parameters. Iodine value, also called iodine number or iodine index, is the mass of iodine in grams absorbed by 100 grams of oil fat.
The processors of oil and fat are in need of a quick determination method of iodine value of oils and fats especially in. It is expressed as the number of grams of iodine that will react with the double bonds in 100 grams of fats, oils, and waxes. Variations in the procedure may affect the results. If the iodine number is to be characteristic of the oil, the sample should be substantially free of moisture and foreign materials. A new calculation method for the determination of iodine value iv from measurements of fatty acid methyl esters is proposed. In the food industry the fatty acid composition of oils and fats is of importance in terms of nutritional values and the chemical and physical properties such as. Standard methods for peroxide value determination in oil sample, which are. Standard test method for determination of the iodine value.
This standard is issued under the fixed designation d 5554. It is defined as the number of parts by mass of iodine absorbed by 100 parts by mass of an oil or fat. This unsaturation is in the form of double bonds, which. Scribd is the worlds largest social reading and publishing site. Pdf standard test method for determination of the iodine. Because the melting point and oxidative stability are related to the degree of unsaturation, iv provides an estimation of these quality factors. Determination of iodine value of oil lipids laboratory. Determination of iodine value iv along with factors like acid value, peroxide value.
Oct 29, 2009 iodine value is a measure of the degree of unsaturation of an oil. Determination of iodine number of activated carbon 1. Determination of saponification and iodine value of sunflower oil. The aocs recommended method d195997 wijs procedure is broadly used for determination of iv. Determination of the acidic value av was performed using the following procedure. To form a double bond, carbon requires more energy 615 kjmol than to form a single bond 350 kjmol. It can be seen from the table that coconut oil is very saturated, which means it is good for making soap. Determination of iodine value iodine value was determined by the standard method 8, official method 920. It is an indication of a fats potential to be oxidized as it measures the reaction of iodine with the double bonds of unsaturated fatty acids 2. Integration of the experiment into an upperlevel biochemistry laboratory is described. An experiment combining ftir spectroscopy with iodometric titrations e. Iodine value of edible oils and fats according to wijs aoac. To calculate the iodine number using the method described, below, all one need do is obtain the volume of na 2.
Determination of iodine value of palm oil by differential scanning calorimetry article pdf available in journal of the american oil chemists society 748. The most common methods used for iodine value determination are the wijs and hanus methods. It is expressed as the number of grams of iodine that will react with the double bonds in 100 grams of fats or oils the determination is conducted by dissolving a weighed sample in a nonpolar solvent such as cyclohexane, then adding glacial acetic acid. Standard methods for the analysis of oils, fats and. This standard is issued under the fixed designation d 5768. Fast spectrophotometric determination of iodine value in biodiesel and vegetable oils. Pdf a direct, quick and nondestructive method for estimating the iodine value of fats, fatty oils and their blends in mineral oils has been. Two collaborative studies were conducted using the wijs method for determining the iodine value in a wide range of vegetable and animal oils and fats. As a general rule, if the iodine number is in the range of 070, then youre looking at a fat. Isco3lab0003 physicochemical characterization of ozonized oil. Results for this 1990 study were submitted by 18 laboratories from 11 countries.
The more the iodine number, the more the number of cc bonds. Determination of the iodine value of oils and fats. Iodine numbers are often used to determine the amount of unsaturation in fatty acids. Pdf standard test method for determination of iodine value.
The processors of oil and fat are in need of a quick determination method of iodine value of oils and fats especially in case of checking the degree of. Determination of the iodine value of selected oils. Iodine value iv is a measure of the total number of double bonds present in fats and oils. Petroleum iodine value of oil and fat kyoto electronics. Estimation of iodine value of fats and oils procedure. Iodine value iv the iodine value is a measure of the relative degree of unsaturation in oil components, as determined by the uptake of halogen. Several methods for the determination of the iodine number of fats and oils have been used. Apr 12, 2018 iodine value, also called iodine number or iodine index, is the mass of iodine in grams absorbed by 100 grams of oil fat. Stir vigorously and filter to obtain clear filterate. Pdf fast spectrophotometric determination of iodine value. Hanus solution iodine monobromide, freshly prepared starch solution, carbon tetrachloride,10% solution of potassium iodide, standard sodium thiosulphate solution n10.
In the routine thyrotropin assay based upon the depletion of iodine in the chick thyroid gland following thyrotropin injections, a rapid micro method for the determination of iodine was desirable. Pdf fast spectrophotometric determination of iodine. Pdf standard test method for determination of iodine. The iodine number of refined corn oil is usually about 125, and this value is. Iodine value can be used to measure the degree of unsaturation of oils and fats. Principle double bonds react with iodine in alcoholic solution determining a variation in the reagents absorbance. This unsaturation is in the form of double bonds which react with iodine compounds. A good drying oil should have iodine value of180andabove. The test sample for the determination of iodine values shall be taken first and the iodine values shall be determined immediately. Add to the blank, 20ml of iodine monochloride reagent and mix the contents in the flask thoroughly. Mean while, take out the test from incubation after 30 minutes and add 10 ml of potassium iodide solution into the flask.
Simple spectrophotometric method for determination of iodine. This parameter is extremely important in the palm oil industry, where it is used to follow the fractionation process. Eugene gooch 1 the chemical educator volume 6, pages 7 9 2001 cite this article. While it is most appropriate for a sophomore or junior laboratory for majors, it also makes a suitable group project or demonstration for nonscience majors. Iodine value, also called iodine number, in analytical chemistry, measure of the degree of unsaturation of an oil, fat, or wax. Determination of iodine value of fats and oil discover. Fat and oil saponification value of fat and oil acid. Pdf determination of iodine value in triisocetyl citrate citmol. Iodine value of edible oils and fats according to wijs.
Because the melting point and oxidative stability are related to the degree of unsaturation, iv provides an. Pdf determination of iodine value of lubricating oils by nuclear. It is expressed as the number of grams of iodine that will react with the double bonds in 100 grams of fats or oils. The iodine value or iodine adsorption value or iodine number or iodine index in chemistry is the mass of iodine in grams that is consumed by 100 grams of a chemical substance. It may be determined by any of the following methods. Fats with high iodine value are normally soft or liquid and are less stable to oxidation. This solution was titrated with koh ethanolic solution until reaching pinkviolet color. In linoleic acid and cod liver oil the hanus method gives 2 to 4 per cent higher values than the other. The double bonds present in unsaturated fatty acids react with the iodine. D 5768 02 standard test method for determination of iodine value of tall oil fatty acids1 this standard is issued under the fixed designation d 5768.
Determination of iodine and saponification values of silver. Determination of iodine value of palm and palmkernel oil by carbona. Estimation of iodine value of fats and oils youtube. Determination of iodine content free download as powerpoint presentation. Determination of acid value acidity, of iodine value, and of peroxide value corrigendaamendments to be made to methods published in the 7th edition new analytical methods developed and adopted by iupac commission vi. The higher the iodine number is, the more unsaturated the fat. It is defined as the percentage of iodine absorbed by the oil under the test conditions. Estimation of iodine value of an oil using hanus solution. Determination of saponification and iodine value of. Iodine value iv iodine value measures the unsaturations content or double bonds which can react with iodine. If the iodine number is between 070, it will be a fat and if the value exceeds 70 it is an oil. Standard test method for determination of iodine value of. It is a measure of degree of unsaturation of fatty acids present in oil.
Petroleum iodine value of oil and fat redox titration by automatic potentiometric titrator standard jis k 0070 astm d 1959 iso 3961 1. China, czechoslovakia, the federal republic of germany 3 finland 2 hungary, japan 2, malayasia, netherlands, new zealand 2, south africa, the united kingdom 2, and the united states. Standard methods for the analysis of oils, fats and derivatives. Calculation of iodine value from measurements of fatty acid. The results obtained when using carbon tetrachloride were compared to those obtained when using a substitute solvent mixture of cyclohexane and glacial acetic acid. The iodine value is a measure of the unsaturation of fats and oils and is expressed in terms of the number of centigrams of iodine. Determination of iodine value of palm oil by differential. It is used in the estimation of the degree of unsaturation in fatty acids. Introduction the iodine value of animal and vegetable fats and oils measures the amount of cc double bonds present in the product. Determination of saponification value determination of unsaponifiable matter determination of acid value determination of iodine value determination of reichert meissl and polenske value bellier test turbidity temperature acetic acid method test for sesame oil baudouins test test for cotton seed oil halphens test. Iodine value is a measure of the number of double bonds in the unsaturated fatty acids in one gram of oil.
Iodine value is a measure of the degree of unsaturation of an oil. Iodine value is directly proportional to the degree of unsaturation of the fat oil ghee. Determination of iodine value and acid value of red fruit oil by infrared spectroscopy and multivariate calibration abstract a rapid method for the quantitative determination of iodine value iv and acid value av of red fruit oil rfo using ftir spectroscopy and multivariate calibration of partial least square pls is described. The method is based on the quantitative determination of fatty acid methyl esters of vegetable oils by capillary gas chromatography. Determination of iodine value of oil the iodine value is a measure of the degree of unsaturation in an oil. Test portion the value obtained depends on the sample mass. Since 450 mg of the oil takes up 26x mg of iodine 1 mg of the oil will take up 26x450 mg of iodine and 100 mg of the oil will take up 260x45 mg of iodine. Determination of phosphorous in soya bean oil determination of nickel in vanaspati. Iodine value is used as a parameter in process control as well as a quality parameter in traded palm oil products. The iodine number equals the number of mg of iodine required to saturate the fatty acids present in 100 mg of the oil or fat. Iv measures the number of double bonds in the molecular structure of an oil.
The results are normally expressed as the number of grams of iodine absorbed by 100 g of oil or fat, considering the conditions of the test. An experiment has been developed that combines the ftir analysis of oils and fats with an iodometric titration. Jul 07, 2012 iodine value is a measure of the number of double bonds in the unsaturated fatty acids in one gram of oil. It must be noted that a high iv value in oil consists of a greater number of double bonds than a low iv oil. Iodine number wijs method principle the vegetable oil sample is reacted with an excess of iodine monochloride solution wijs reagent under controlled conditions.
Homogenize the sample, preferably without heating and without aeration. Determination of iodine value of fats and oil discover food. Starch is used as the indicator for this reaction so that the liberated iodine will react with starch to give purple coloured product and thus the endpoint can be observed. Saponification value, ester value, iodine value and hydroxy value of chemical products and unsaponifiables 2 astm d 555895 standard test method for determination of the saponification value of fats and oils 3 iso 3657. Standard methods for peroxide value determination in oil sample, which are based on volumetric titration by sodium thiosulphate. Determination of iodine value and acid value of red fruit. To determine the iodine value of fats and oils and thus estimate the unsaturation of the fat oil. The higher the iodine value, the more unsaturated fatty acid bonds are present in a fat. Eight samples of deepfrying cooking oil were collected at two selected night market at kepala batas. Iodine value iv is used as a parameter in process control as well as a quality parameter in traded palm oil products. Iv is a measure of the number of double bonds in the unsaturated fatty acids in one gram of oil. Determination of the iodine value of oils and fats results of.
Hence the iodine number of the oil is 260x45 results and discussion the iodine number is an important characteristic of oils as it. Determination of the iodine value of oils and fats results. The determination of iodine value was based on the discoloration of an aqueous triiodide solution added to biodiesel or vegetable oil, due to the halogenation of the. On the other hand, linseed oil is highly unsaturated, which makes it a drying oil, well suited for making oil paints. Determination of iodine and saponification values of. Contents hide 1 table of iodine values 2 methodology 3 methods for the determination of iodine value 3. Saponification value or saponification number, also referred to as sap in short, represents the number of milligrams of potassium hydroxide or sodium hydroxide required to saponify 1g of fat under the conditions specified. Abstract test method for measurement of iodine value of fats and oils stipulated in the below. The mean value of the blank determination method 051b is automatically stored as auxiliary value h3.