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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Soxhlet Alat Ekstraksi Lipid Documents. Lipid contents can often be determined in a few seconds without the need for any sample preparation using commercially available instruments. Analisis Lemak Metode Soxhlet Documents. Solid Fat Content The solid fat content SFC of a lipid influences many lemakk its sensory and physical properties, such as spreadability, firmness, mouthfeel, processing and stability.
TBARS is an example of a measurement of the increase in concentration of secondary reaction products. The solid fat content is defined as the percentage of the total lipid that is solid at a particular temperature, i. In many foods the lipid component plays a major role in determining the overall physical characteristics, such as flavor, texture, mouthfeel and appearance.
The smoke point is the temperature at which the sample begins to smoke when tested under specified conditions. Most rheological tests involve applying a force to a material and measuring its flow or change in shape.
Kesepuluh, diambil bahan cairan yang diperoleh dan diukur volumenya kemudian ditimbang. Pada hasil ekstraksi akan dihasilkan berupa minyak kemiri yang relative murni Alfin. Saponification Number The saponification number is a measure of the average molecular weight of the triacylglycerols in a sample.
Grinding is often carried out at low temperatures to reduce the tendency for lipid oxidation to occur. Nevertheless, foods lipids contain a wide variety of different analisus, each with their own unique melting point, and so they melt over a wide range of temperatures.
Sample Preparation It is important that the sample chosen for analysis is representative of the lipids present in the original food, and that its properties are not altered prior to the analysis. Kesembilan, dibiarkan cairan dingin kemudian diambil hasil ektraksi dan dimasukkan dalam rotary evaporator vaccum.
Spots can be scraped off and analyzed further using techniques, such as GC, NMR or mass spectrometry. The fire point is the temperature at which evolution of volatiles due to the thermal decomposition of the lipids proceeds so quickly that continuous combustion occurs a fire.
Government regulations often demand that the amounts of saturated, unsaturated and polyunsaturated lipids, as well as the amount of cholesterol, be specified on food labels. For this reason, starch is usually used as an indicator because it forms a molecular complex with the iodine that has a deep blue color.
The density of liquid oil is less than that of most other food components, and so there is a decrease in density of a food as its fat content increases.
This group analidis substances includes triacylglycercols, diacylglycercols, monoacylglycercols, free fatty acids, phospholipids, sterols, caretonoids and vitamins A and D. Liquid oils are usually characterized in terms of their flow properties viscositywhereas viscoelastic or plastic “solids” are characterized in terms of both their elastic elastic modulus and flow properties.
The concentration of oil droplets llemak 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. Instruments based on this principle heat the food sample to be analyzed in a pressurized chamber and then mix supercritical CO2 fluid with it.
Below a certain stress known as the “yield stress” the product behaves like a solid with 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.
Disini sampel disimpan dalam alat Soxhlet dan tidak This is not a problem in the Soxhlet method because the sample is always surrounded by solvent. This technique is capable of rapid, nondestructive on-line measurements of lipid content.
Chromatography can be used to determine the complete profile of molecules present in a lipid. A variety of methods have been developed to measure the temperature dependence of the solid fat content. These can be divided into three different categories according to their physicochemical principles: This method is therefore analisi useful for monitoring the early stages of lipid oxidation.
A wide variety of experimental techniques are available to characterize the rheological properties of food materials.
NMR spectroscopy is routinely used to determine the total lipid concentration of foods. Fatty acid methyl esters by GC Intact triacylglycerols and free fatty acids are not very volatile and are therefore difficult to analyze using GC which requires that the lipids be capable of being volatized in the instrument.
Konsentrasi Reaksi refluks Re-kristalisasi As the solvent passes through the sample it extracts the lipids and carries them into the flask.