On the determination of iodine value by the wijs method. Calculation of iodine value from measurements of fatty acid. Analyses of 25 fats and oils showed that the ratio of absorbance at 3. Iodine value, also called iodine number, in analytical chemistry, measure of the degree of unsaturation of an oil, fat, or wax. How to determine unsaturation in food oils and fats. The peroxide value is a parameter specifying the content of oxygen as peroxide, especially hydroperoxides in a substance. A simple, rapid and reproducible method of determining the iodine value iv and saponification number sn for fats and oils was developed with an attenuated total reflectancefourier transform infrared spectrometer and commercially available triglycerides as calibration standards. 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 unsaturation of them in the hydrogenation process. The iodine value or iodine adsorption value or iodine number or iodine index, commonly abbreviated as iv in chemistry is the mass of iodine in grams that is consumed by 100 grams of a chemical substance. A b s t r a c t the iodine value iv also called iodine number or iodine absorption value is an important analytical characteristic of unsaturation of fats and oils. Quantitative determination of the iodine values of unsaturated plant oils using infrared and raman spectroscopy methods.
The iodine value for native oils fats of defined plant origin is easily accessible from tables or from the fat supplier table 3. The determination of the iodine values of fats and oils by winklers bromate method. The described procedures, visual and potentiometric, have wide applicability and generate. Of the various methods and modifications that have been proposed from time to time for the determination of the iodine values of fats and oils, hubls and wijs are the only two.
Saponification value, iodine value, smoke point, and the flashpoint of flavored oil. Analytical methods to evaluate the quality of edible fats and oils. In our experience, it is an important and easily available parameter in fat selection. International journal of food properties 2017, 20 9. Therefore, the present method represents a rapid and accurate tool for measuring iv of edible fats and oils. Fatty acid composition as determined by gas chromatography % total fatty acids. So, the basic objective of this test is to determine the iodine number of fat. Impact of dietary fat intake on carcass iodine value and pork. Physicochemical constants such as the iodine value, the saponification value, the refractive index, the combustion heat, the specific gravity, the neutralization value, the iodine saponification factor, and the hardness.
Aug 21, 2019 en iso 3961 animal and vegetable fats and oils determination of iodine value astm d5554 standard test method for determination of the iodine value of fats and oils aoac 920. The refined oils were blended to produce three samples of margarine. Iodine value wijs method pdf amaryl lids to download pdf. Determination of physicochemical and functional properties of. Bellier test turbidity temperature acetic acid method 35 15. Margarine production using oil blends from palm kernel. 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 absorbed per gram of sample. The values given in parentheses are for information only. A modified determination of iodine value in fats, fatty acids, and fatty acid derivatives is reported. The next section describes the determination procedure of physicochemical properties of determined oil, fats, and derivatives. A rapid and practical method for determining the iodine value iv of edible oils or fats with an ftir spectrometer combined with a quartz cuvette was reported.
Jul, 2018 acid value major constituents of fats and oil are tag. The iodine value in chemistry is the mass of iodine in grams that is consumed by 100 grams of a chemical substance. Determination of iodine and saponification values of silver. Authors have investigated other methods of quick determination of iodine value especially for the. Pdf standard test method for determination of iodine value. The determination is conducted by dissolving a weighed sample in a nonpolar solvent such as cyclohexane, then adding glacial acetic. Calculation of iodine value from measurements of fatty. The determination of the poz is done by titration with sodium thiosulfate after reaction of the sample with potassium iodide, wherein the iodide is oxidized by the peroxides to iodine. Standard test method for determination of iodine value of. Iodine value of fats and oils wijs cyclohexaneacetic acid solvent method first action 1993 final action 1996 iupacaocsaoac method applicable to determination of iodine value for fats and oils which do not contain conjugated double bonds. Iodine monochloride reagent potassium iodide standardized 0. Annex a describes a method for the calculation of the iv from fatty acid compositional data.
Iodine value is directly proportional to the degree of unsaturation of the fat oil ghee. Jun 19, 2020 iodine value means the g value of halogen which adhere to g of methods such as hanus method and wijs method for iodine value. Discussion in this experiment, physical properties of butter and margarine are determined by determination of melting point. Cd 1b87 iodine value of fats and oils cyclohexane method cd 1c85 calculated iodine value cd 1d92 iodine value of fats and oils, cyclohexaneacetic acid method cd 1e01 iodine value by precalibrated ftnir cd 238 surplus thiocyanogen value cd 2091 polar compounds in frying fats cd 2191 benzoapyrene in edible oils and fats. 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.
This method describes the determination of peroxide values for animal oils and fats, vegetable oils and fats, as well as for flavour and fragrance materials. Iodine value is a measure of unsaturation of oils and fats. To determine the iodine value of fats and oils and thus estimate the unsaturation of the fats and oils. Moisture content of oils and fats is the loss in mass of the sample on heating. Triglycerides are made up of three fatty acids linked to glycerol by fatty acyl esters. Rapid and direct lodine value and saponification number. A simple and practical method for determining iodine. Both sv and iv are measured by the titration methods. The iodine value is a measure of the unsaturation 3. Saponification valuesv and iodine valueivare determined by the fatty acid composition of edible fats and. Din en iso 3961 animal and vegetable fats and oils determination of iodine value iso 3961. Determination of iodine value pharma qualification. Determination of the iodine value of oils and fats. Next, palm oil and corn oil are determined by determination of specific gravity sg and refractive index ri.
A simple and practical method for determining iodine values of oils. Determination of acid value acidity, of iodine value, and of peroxide value. Annex b describes a method for the calculation of the iv from fatty acid compositional data. A new calculation method for the determination of iodine value iv from measurements of fatty acid methyl esters is proposed.
Iodine value refers to the percentage of iodine absorbed by a substance such as a fat or oil 1. 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. Physicochemical constants such as the iodine value, the saponification value, the refractive index, the combustion heat, the specific gravity, the neutralization value, the iodine saponification factor, and the hardness number are up to now the most important and the most often. This video channel is developed by amrita universitys create. Iodine value of edible oils and fats according to wijs aoac. A simple and practical method for determining iodine values. Iodine value wijs method pdf new pdf download service. The more unsaturated the fatty acid, the greater the iodine value iv. Pdf standard test method for determination of iodine.
Iodine numbers are often used to determine the amount of unsaturation in fats, oils and waxes. In fatty acids, unsaturation occurs mainly as double bonds which are very reactive towards. Iodine value of edible oils and fats according to wijs. Determination of physicochemical constants of fats and oils. Iv is a measure of the number of double bonds in the unsaturated fatty acids in one gram of oil. To retard rancidity keep oils and fats in cool place and protect from light and air. This icl adds on to the double bonds present in the oil.
Dietary fats and oils are highly digestible and dense sources of energy associated with. Iodine value wijs method pdf to download pdf you need. Unused icl reacts with ki solution and liberates an equivalent amount of iodine, which is titrated against standard sodium thiosulphate solution. The peroxide value is a measure of the oxidation present. Laboratory report on biochemistry of fats and oils. Pdf standard test method for determination of the iodine. Determination of physicochemical constants of fats and. Ftir method combined with interval optimization is described to determine the iodine value in edible oil. Coconut oil is one of the widely used cooking oil in many asian countries 1. Patterson, in hydrogenation of fats and oils second edition, 2011 iodine value iv iodine value iv is the percentage of its own weightwith which a fat will combineof halogen calculated as iodine, the conditions of the test being indicated. The method is based on the quantitative determination of fatty acid methyl esters of vegetable oils by capillary gas chromatography. 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.
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 most popular procedure is known as the wijs method, but all methods suppose that a normal carboncarbon double bond takes up two atoms. Comparison of determination of iodine value in edible oils by hanus. Pdf determination of iodine value in triisocetyl citrate. Analytical methods to evaluate the quality of edible fats. This document specifies a reference method for the determination of the iodine value commonly known in the industry as iv of animal and vegetable fats and oils, hereinafter referred to as fats. Determination of iodine value of fats and oil discover food. Iodine value determination of edible oils using atr. Kaufmann huebls iodine introduced the iodine value was hubl which titrated fats in the presence of mercuric chloride with iodine, but with the actual reagent probably iodine chloride is formed in situ from mercuric chloride and iodine.
The sample was diluted with carbon tetrachloride and poured into a quartz cuvette thickness. Standard test method for determination of the iodine value. Determination of iodine value iv along with factors like acid value, peroxide value. Standard methods for the analysis of oils, fats and. Unsaturated oils and fats become rancid by oxidation, forming peroxides. Determination of iodine and saponification values of. This study aimed to determined peroxide value, iodine value and free fat. Jan, 2017 a general iv model that incorporates several oil types is expected to improve prediction performances. Standard methods for the analysis of oils, fats and derivatives. Jan 18, 2019 iodine value means the g value of halogen which adhere to g of methods such as hanus method and wijs method for iodine value. Standard test method for determination of the iodine value of. When oil is treated with excess of wijs solution i.
Partial least squares was used to determine the spectral regions correlating with the known chemical iv and sn. Such characteristics include density, refractive index, color, dilatation, acid, ester, iodine value, and moisture and volatile matter content this book will prove useful to analytical chemists and researchers in the. Fatty acids are long chain hydrocarbons with carboxyl groups cooh groups. Estimation of iodine value of fats and oils theory. Determination of peroxide value pov in fats and oils. Determination of the iodine value of oils and fats results of. Also, to understand various identification tests for oils and fats, acquire the skill to identify saturated and unsaturated fats, and acquire skill to perform the experiment in the real lab. Methods are available to determine iv of fats and oils, such. Free fatty acids as neutralized with koh in the determination acid value is defined as the no. The iodine value is in direct proportion to the number of mono and polyunsaturated bonds within the constituent fatty acids. Estimation of iodine value of fats and oils procedure.
Apr 22, 2018 methods for the determination of iodine value huebls iodine wijs iodine value iodine by h. Iodine value iv is a measure of the total number of double bonds present in fats and oils. Jan 14, 2020 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. Determination of iodine value iv in fats and oils with. Estimation of iodine value of fats and oils amrita university. 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 mean value of the blank determination method 051b is automatically stored as auxiliary value h3. Determination of reichert meissl and polenske value 30 14.
To determine the iodine value of fats and oils and thus estimate the unsaturation of the fat oil. Determining if fatty acid composition impacts the energy value of the dietary fat is. The results obtained when using carbon tetrachloride were compared to those obtained when using a substitute solvent mixture of cyclohexane and glacial acetic acid. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are.
For measuring the sv, edible fats and oils are refluxed together with known quantity of potassium hydroxide in ethanol solution. Next, this laboratory report aims to to determine the iodine value of fats and oils and thus estimate the unsaturation of the fats and oils. Based on the data in determination of melting point, the melting range for margarine sample is within 41. Saponification value svand iodine value ivare determined by the fatty acid composition of edible fats and oils, as shown in table 2. Pdf determination of iodine value of palm based on triglyceride.
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