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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Massa jenis densitas hasil ekstraksi dihitung dengan mennggunakan persamaan: Thiobarbituric acid TBA This is one of the most widely used tests for determining the extent of lipid oxidation. Sifat fisik dan Kimia dari Minyak Kemiri adalah sebagai berikut Kataren, By definition the iodine value is expressed as the grams of iodine absorbed per g of lipid.
Below a certain stress known as the “yield stress” the product behaves like a solid lemwk an elastic modulus because the crystal network is not disrupted, but above this stress it flows like a liquid because the crystal network is continually disrupted.
Soxhlet Alat Ekstraksi Lipid Documents. Ideally, the composition of the sample analyzed should represent as closely as possible that of the food from which it was taken.
Characterization anwlisis Physicochemical Properties5. Padatan yang terbungkkus kertas saring dimasukkan kedalam alat ekstraksi soxhlet. Rheological techniques are therefore needed to measure the change in deformation of a lipid when stresses are applied. These instruments are finding greater use because of the cost and environmental problems associated with the usage and disposal of organic solvents. Pengaruh Suplementasi Lisin terhadap Karakteristik Karkas Thus different molecules can be separated on the basis of the strength of their interaction with the matrix.
The aqueous phase is then decanted off, and the concentration of lipid in the solvent is determined by evaporating the solvent and measuring the mass of lipid remaining: Determination of the total fatty acid profile allows one to calculate the type and concentration of fatty acids present in the original lema sample. Lfmak of the most commonly used methods for determining the iodine value of lipids is “Wijs method”.
Accelerated Oxidation Tests Rather than determining the extent of lipid oxidation in a particular food, it zoxhlet often more important to know its susceptibility to oxidation. Some of the most important reasons for determining the type of lipids present in foods are listed below: The smaller the saponification number the larger the average molecular weight of the triacylglycerols present.
Polar lipids such as glycolipids or phospholipids are more soluble in polar solvents such as alcoholsthan in non-polar solvents such as hexane. This technique is capable of rapid, nondestructive on-line measurements of lipid content.
More recently, instrumental methods based on nuclear magnetic resonance NMR have largely replaced density measurements, because measurements are quicker and simpler to carry out although the instrumentation is considerably more expensive.
Kesebelas, tentukan beraj jenis mennggunakan piknometer.
TBARS is an example of a measurement of the increase in concentration of secondary reaction products. The Babcock, Gerber and Detergent methods are examples of nonsolvent liquid extraction methods for determining the lipid content of milk and some other dairy products.
Lipids can sometimes be extracted by simply applying pressure to a food to squeeze out the oil, e. Kedelapan, dilakukan ekstraksi 6 kali sirkulasi pelarut n-heksana. Melting point In many situations, it is not necessary to know the SFC over the whole temperature range, instead, only information about the temperature at which melting starts or ends is required.
Kemudian padatan yang telah halus dibungkus dengan kertas saring. By making these measurements over a range of temperatures it is possible to determine the melting point, the total amount of lipid involved in the transition and the SFC-temperature profile.
It is possible to monitor the loss of reactants e. In addition, most of these sub-groups are themselves chemically complex.
Iodine Value The iodine value IV gives a measure of the average degree of unsaturation of a lipid: This solution is then heated so that the reaction goes to completion.
The percentage of lipid in the initial sample Msample can then be calculated: Food manufacturers often measure the variation of SFC with temperature when characterizing lipids that are used in certain foods, e. This procedure is inexpensive and allows rapid analysis of lipids in fatty foods. Pelarut organic dimasukkan kedalam labu alas bulat.
Kesepuluh, diambil bahan cairan yang diperoleh dan diukur volumenya kemudian ditimbang. Thus, a change in solution appearance from blue to colorless can be used as the end-point of the titration. A fat is poured into a metal container and heated at a controlled rate in an oven.
Leak Foods which contain high concentrations of unsaturated lipids are particularly susceptible to lipid oxidation. The sample preparation required in lipid analysis depends on the type of food being analyzed e.
Smoke, Flash and Fire Points These tests give a measure of the effect of heating on the physicochemical properties of lipids.
Published on Jul View 6. The iodine value is used to obtain a measure of the average degree of unsaturation of oils, and to follow processes such as hydrogenation and oxidation that involve changes in the degree of unsaturation. Analisis Lemak Dalam Makanan Documents.