Seven important parameters for analysis of edible oils and. To determine the iodine value of fats and oils and thus estimate the unsaturation of the fat oil. The result is expressed as g of iodine i2 per 100 g of sample. 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. The acid number is the quantity of base, expressed in milligrams of potassium hydroxide, that is required to. The iodine number is defined as the grams of halogen, expressed as iodine, reacting. The calculation of the % ffa depends on the titrated type of sample. The iodine value iv indicates the degree of unsaturation of a fat or oil. Estimation of iodine value of fats and oils amrita university.
Annex b describes a method for the calculation of the iv from fatty acid compositional data. Standard test method for determination of the iodine value. Thus, ffa is a key feature linked with the quality and commercial value of oils and fats. 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 test sample % iodine absorbed. An experiment has been developed that combines the ftir analysis of oils and fats with an iodometric titration. Add to the blank, 20ml of iodine monochloride reagent and mix the contents in the flask thoroughly. Determination of reichert meissl and polenske value. 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 ffa and iodine value campuscrosswalk. 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 values given in parentheses are for information only.
An experiment on the determination of iodine number of fats and oils by coulometric titration. The larger the iodine value the greater the degree of unsaturation. Determination of acid value acidity, of iodine value, and of peroxide value. Determination of iodine value iv in fats and oils iodine value iv is a measure of the total number of double bonds present in fats and oils. The oil content, peroxide, acid, iodine, panisidine values and. Pdf analytical approaches for free fatty acids assessment in oils. The next section describes the determination procedure of physicochemical properties of determined oil, fats, and derivatives.
Bellier test turbidity temperature acetic acid method 35. Mean while, take out the test from incubation after 30 minutes and add 10 ml of potassium iodide solution into the flask. Iodine value of edible oils and fats according to wijs. The iodine value can be determined for fats and oils with thermometric titration, by dissolving a weighed sample in a nonpolar. The determination is carried out by dissolving a weighed sample in a nonpolar solvent such as cyclohexane. Fatty acids react with a halogen iodine resulting in the addition of the halogen at the cc double bond site. Triglycerides are made up of three fatty acids linked to glycerol by fatty acyl esters. The determination of the peroxide values of edible fats.
What is the standard procedure to determine the iodine. Quantitative determination of the iodine values of. It is expressed as the iodine in grams that will react with the double bonds in 100 grams of fats or oils. Scope applicable to all normal fats and oils with iodine values in the range of 18165 that do not. 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. 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. The higher the iodine value, the more unsaturated fatty acid bonds are present in a fat. Iodine value test of palm oils in just 2 minutes with cdr palmoiltester.
To determine the iodine value of fats and oils and thus estimate the unsaturation of the fats and oils. Kaufmann 4 related methods of analysis 5 references table of iodine values edit fat iodine number1 tung oil 163 173 cod liver oil 145 180 grape seed oil 124 1442 palm oil 44 51 butter 26 40. Reference values for these parameters were obtained from oils using a previously developed mid. The iodine value in chemistry is the mass of iodine in grams that is consumed by 100 grams of. The method is suitable for edible fats and oils such as butter, olive, palm or sunflower oil. On the other hand, oils are also widely demanded for biodiesel production e.
Standard test method for determination of iodine value of. The determination of the peroxide values of edible fats and oils. As a general rule, if the iodine number is in the range of 070, then youre looking at a fat. 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. Bellier test turbidity temperature acetic acid method. It is defined as the number of grams of iodine absorbed by 100 g of fat. Annex a describes a method for the calculation of the iv from fatty acid compositional data. Estimation of iodine value of fats and oils theory. 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. Albegarb, adam zajaca, kamil kostync, jadwiga lorenca, and jerzy hanuzad adepartment of bioorganic chemistry, institute of chemistry and food technology, faculty of engineering and. Determination of reichert meissl and polenske value 30 14. The vegetable oil sample is reacted with an excess of iodine. The result of the titration is recorded in a table for calculation. Manual on oils and fats food safety and standards authority.
The mean value of the blank determination method 051b is automatically stored as auxiliary value h3. The iodine number equals the number of mg of iodine required. For determinations in which results might be affected by possible presence of water e. The higher the iodine number is, the more unsaturated the fat. Determination of iodine value of oil the iodine value is a measure of the degree of unsaturation in an oil. 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. Because the melting point and oxidative stability are related to the degree of unsaturation, iv provides an estimation of these quality factors. The procedure is applicable to fats and oils from corn, grain sorghum and other.
Determination of the iodine value of selected oils. The determination is conducted by dissolving a weighed sample in a nonpolar solvent such as cyclohexane, then adding glacial acetic acid. Determination of iodine value iv along with factors like acid value, peroxide value, saponification value, solid fat index, refraction value, and trans fatty acid content is an important factor. Determination of iodine value of fats and oil discover. Pdf standard test method for determination of the iodine. Determination of iodine value iv along with factors like acid value, peroxide value, saponification value, solid fat index, refraction value, and. The higher the iodine number, the more cc bonds are present in the fat. Iodine value iv is a measure of the total number of unsaturated double bonds present in fats and oils. Twentytwo laboratories participated in a collaborative test to determine the iodine value iv of eight samples of fish oil four with iv 150 with either carbon tetrachloride aocs official method cd 125 or cyclohexane aocs recommended practice cd 1b87 as solvent and either 1 or 2 h of reaction time. Free fatty acids ffa are produced by the hydrolysis of oils and fats. On the other hand, linseed oil is highly unsaturated, which makes it a drying oil, well suited for. This unsaturation is in the form of double bonds which react with iodine compounds. Determination of iodine and saponification values of.
Enthalpimetric determination of the iodine value of some edible oils and fats. From this alignment chart we can read the saponi fication value, refractive index, neutralization value, specific gravity, combustion heat, iodinesaponification. This video looks at both the practical procedure and the calculation, for obtaining the iodine values of fats and oils. Determination of the iodine value of oils and fats results. Determination of iodine numbers analytical chemistry. It is expressed as the number of grams of iodine that will react with the double bonds in 100 grams of fats or oils. If the iodine number is to be characteristic of the oil, the sample should be substantially free of moisture and foreign materials. Fast spectrophotometric determination of iodine value in biodiesel. An experiment on the determination of iodine number of fats and oils by coulometric titration journal of chemical education.
Lea low temperature station for research in biochemistry and biophysics, university of cambridge and department of scientific and industrial research. Collaborative test of determination of iodine value in. Iodine value test with cdr palmoiltester palm oil analysis system. Some differences in composition of covering fat, intermuscular fat, and intramuscular fat of meat animals. It is normally expressed in terms of number of grams of iodine that will react with the double bonds in 100 grams of fats or oils. Nir spectroscopy was evaluated as a means of simultaneously determining the cis and trans content, iodine value iv, and saponification number of neat fats and oils. The results of a statistical evaluation of the iodine values obtained in the 1st collaborative study in which 11 laboratories from 9 countries participated are summarised in table 2. To calculate the iodine number using the method described, below, all one need do is obtain the volume of na 2.
Determination of physicochemical constants of fats and oils from the. Iodine number is a measure of the total number of double bonds present in fats and oils. Triglycerides are made up of three fatty acids linked to glycerol by fatty acy. Fat and oil saponification value of fat and oil acid. The determination is carried out by dissolving a weighed sample in a nonpolar solvent such as cyclohexane, then adding glacial acetic acid. Aocs official method cd 1d92 american oil chemists society. Integration of the experiment into an upperlevel biochemistry laboratory is described. Standard methods for the analysis of oils, fats and. Iodine value or number is the number of grams of iodine consumed by 100g of fat. Introduction the acid value av is a common parameter in the specification of fats and oils. A higher iodine value indicates a higher degree of unsaturation. Iodine value means the g value of halogen which adhere to g of methods such as hanus method and wijs method for iodine value. Astm d5554 standard test method for determination of the iodine value of fats and oils aoac 920. Determination of iodine value iv in fats and oils with thermometric.
Determination of iodine value of palm oil by differential scanning calorimetry article pdf available in journal of the american oil chemists society 748. The iodine value or iodine adsorption value or iodine number or iodine index in chemistry is the mass of iodine in grams that is. 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. Introduction the iodine value of animal and vegetable fats and oils measures the amount of cc double bonds present in the product. 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. Iodine value iv is a measure of the total number of double bonds present in fats and oils.
Estimation of iodine value of fats and oils youtube. Rapid determination of cis and trans content, iodine value. The fatty acids can be saturated or unsaturated depending on the number of carboncarbon double bonds. 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. Iodine numbers are often used to determine the amount of unsaturation in fatty acids. Iodine value, also called iodine number, in analytical chemistry, measure of the degree of unsaturation of an oil, fat, or wax. Fatty acids are long chain hydrocarbons with carboxyl groups cooh groups. 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. This standard is issued under the fixed designation d 5554.
Quantitative determination of the iodine values of unsaturated plant oils using infrared and raman spectroscopy methods lucyna dyminska a, maciej calik, abduladhim moamer m. Determination of iodine value of oil lipids laboratory. Estimation of iodine value of fats and oils procedure. Abstract vegetable oils are triglycerides extract from plants and made of up of fatty acid chains. Determination of saponification and iodine value of. It is defined as the weight of koh in mg needed to neutralize the organic acids present in 1g of fat and it is a measure of the free fatty acids ffa in a sample of oil or fat indicates hydrolysis of triglycerides.
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