ANALISIS LEMAK SOXHLET PDF
PREPARASI SAMPEL Pengeringan sampel. Analisis Kadar Lemak dalam Bahan Pangan. PERALATAN SOXHLET Analisis Sifat Fisiko-Kimia Lemak atau. Berat lemak diperoleh dengan cara memisahkan lemak dengan pelarutnya. dll. dietil ksi Soxhlet Prinsip Analisis • Ekstraksi lemak dengan pelarut. Analisa lemak kasar: Metode ekstraksi soxhlet dengan pelarut organik Analisa serat kasar: Fraksi dari karbohidrat yang tidak larut dalam basa dan asam.
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Semi-Continuous Solvent Extraction Semi-continuous solvent extraction methods are commonly used to increase the efficiency of lipid extraction from foods. An aqueous solution of TBA reagent is added to the flask and the sample is shaken, which causes the polar secondary products to be dissolved in it. IR is particularly useful for rapid and on-line analysis of lipid content once a suitable calibration curve has been developed.
The smoke point is the temperature at which a thin continuous stream of bluish smoke is first observed.
Thus foods which are almost entirely lipids, such as olive oil, vegetable oil or lard, can usually be analyzed with little sample preparation. On the other hand, non-polar lipids such as triacylglycerols are more soluble in non-polar solvents than in polar ones. Techniques based on differential scanning calorimetry are also commonly used to monitor changes in SFC.
A small amount of the lipid sample to be analyzed is spotted onto the TLC plate. Another widely used accelerated oxidation test is the Schaal Oven Test.
Massa jenis densitas hasil ekstraksi dihitung dengan mennggunakan persamaan: This technique is capable of rapid, nondestructive on-line measurements of lipid content. The Soxhlet method is the most commonly used example of a semi-continuous method.
The density is usually measured by density bottles or dilatometry. Bahan Adapaun bahan0bahan yang kami gunakan dalam percobaan ekstraksi soxhlet antara lain: Lipid fractions by TLC TLC is used mainly to separate and determine the concentration of different types of lipid groups in foods, e.
In this case the aqueous phase would undergo further extractions using fresh solvent, then all the solvent fractions would be collected together and the lipid determined by weighing after evaporation of solvent. It measures the concentration of relatively polar secondary reaction products, i. They are particularly important for selecting lipids that are going to be used at high temperatures, e.
Peroxide value Peroxides R-OOH are primary reaction products formed in the initial stages of oxidation, and therefore give an indication of the progress of lipid oxidation. By comparing the distance that the spots move with standards of known composition it analosis possible to identify the lipids present.
A disc of fat is suspended in an alcohol-water mixture of similar density and lemaak then heated at a controlled rate. The lipid to be analyzed is dissolved in a suitable nonpolar solvent which is contained lejak a flask. Aalisis CO2 extracts the lipid, and forms a separate solvent layer, which is separated from the aqueous components.
The concentration of different volatile fatty acid methyl esters FAMEs present in the sample is then analyzed using GC.
Thus the lipid content can be determined by measuring its ultrasonic velocity. The concentration of oil droplets in concentrated food emulsions can be determined using ultrasonic scattering techniques because the ultrasonic velocity and absorption of ultrasound by an emulsion is related to the concentration of oil droplets present.
Measurement of bulk physical propertiesDensity: This method is based on the absorbance of IR energy at a wavelength of 5.
These measurements may be made on non-polar lipids extracted from the food, watersoluble reaction products present in the aqueous phase analusis a food or volatile components in the head-space of a food. Saponification Number The saponification number is a measure of the average molecular weight of the triacylglycerols in a sample. A fat sample is heated to a temperature where all lemmak crystals are known to have melted e. Published on Nov View Download 4. Sample Preparation The preparation of a sample for solvent extraction usually involves a number of steps: Padatan yang terbungkkus kertas saring dimasukkan kedalam alat ekstraksi soxhlet.
The concentration of lejak droplets in dilute food emulsions can be determined using light scattering techniques because the turbidity of an emulsion is directly proportional to the concentration of oil droplets present.
Instrumental methods are most useful for rapid measurements of fat content on-line or in ahalisis assurance laboratories of food factories where many samples must be measured rapidly. By definition the iodine value is expressed as the grams of iodine absorbed per g of lipid. The lipid content of a food is determined analisie weighing the percentage of lipid extracted from the original sample.
Chromatography can be used to determine the complete profile of molecules present in a lipid. Thiobarbituric acid TBA This is one of the most widely used tests for determining the extent of lipid oxidation.
The signal from the solid fat decays much more rapidly than the signal from the liquid oil and therefore it is possible to distinguish between these two components. Kelima, dimasukkan beberapa batu didih dalam labu alas bulat. A variety of methods have been developed to measure the temperature dependence of the solid fat content.
When pressurized CO2 is heated above a certain critical temperature it becomes a supercritical fluid, which has some of the properties of a gas and some of a liquid. Nevertheless, over-consumption of certain lipid components can be detrimental to our health, e. Smoke, Flash and Fire Points These tests give a measure of the effect of heating analidis the physicochemical properties of lipids. Rheology The rheology of lipids is important in many food applications.
The concentration of certain lipids can be determined by measuring the absorbance of ultraviolet-visible radiation. Soxhlet Extractions – Soxhlet Extractions Author: Lean meat absorbs X-rays more strongly than fat, thus the X-ray absorbance decreases as the lipid concentration increases. Measurements of the overall electrical conductivity of foods can therefore be used to determine fat contents.
Ekstraksi Soxhlet kimia pemisahan Documents. For this reason lipids are usually derivitized prior to analysis to increase their volatility. Analisis Proksimat Lemak Kel1 Documents.