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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The more oxygen that has to be fed into the container, the faster the rate of lipid oxidation.
analiss Thus it is possible to monitor the rate at which it occurs by measuring the uptake of oxygen by the sample as the reaction proceeds. The flash point is the temperature at which a flash appears at any point on the surface of the sample due to the ignition of volatile gaseous products.
This solution is then titrated with alkali KOH until a pinkish color appears. The concentration of different volatile fatty acid methyl esters FAMEs present in the sample is then analyzed using GC. Kelima, dimasukkan beberapa batu didih dalam labu alas bulat. Rheology is the science concerned with the deformation and flow of matter.
Acid hydrolysis is commonly used to release bound lipids into easily extractable forms, e. Detergent Method This method was developed to overcome the inconvenience and safety concerns associated with the use of highly corrosive acids.
The acid value is spxhlet a good measure of the break down of the triacylglycrols into free fatty acids, which has an adverse effect on the quality of many lipids. Even so there is always some concern that the results of accelerated tests do not adequately model lipid oxidation in real systems.
In the later stages of lipid oxidation the conjugated dienes which are primary products are broken down into secondary products which do not adsorb UV-visible light strongly which leads to a decrease in absorbance.
The density is usually measured by density bottles or dilatometry. Lipids can sometimes be extracted by simply applying pressure to a food to squeeze out the oil, e. Lrmak of the most important rheological characteristics of lipids is their “plasticity”, because this determines their “spreadability”. A small amount of the lipid sample to be analyzed is spotted onto the TLC plate. 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.
Foods which contain high concentrations of unsaturated lipids are particularly susceptible to lipid oxidation, which can lead to theformation of undesirable off-flavors and aromas, as well as potentially toxic compounds e. Analisis Pembuatan Asam Lemak Documents. Melting point In many situations, it is not necessary to know the SFC over the lemka temperature range, instead, only information about the temperature at which melting starts or ends is required.
Some of the ICl reacts with the double bonds in the unsaturated lipids, while the rest remains: The refractive index increases with increasing chain length and increasing unsaturation, whereas the density decreases with increasing chain length and decreasing unsaturation.
Ideally, the composition of the sample analyzed should represent as closely as possible that of the food from which it was taken. In the Soxhlet method a sample is dried, ground into small particles and analisks in sxhlet porous thimble. Spots can be scraped off and analyzed further using techniques, such as GC, NMR or mass spectrometry. Pelarut yang baik dalam ektraksi soxhlet adalah pelarut yang mempunyai titik didih rendah seperti nheksana yang mempunyai titik didih 69oC agar cepat menguap sehingga tidak menyebabkan kerusakan pada alat dan juga tidak membutuhkan watu yang lama untuk melakukan satu sirkulasi ektraksi.
The saponification number is then calculated from a knowledge of the weight of sample and the amount of KOH which reacted. The surfactants displace the fat globule membrane which surrounds the emulsion droplets in milk and causes them to coalesce and separate. Nonsolvent Liquid Extraction Methods.
This solution is then heated so that soxhleet reaction goes to completion. In fact, solvent extraction techniques are one of the most commonly used methods of isolating lipids from foods and of determining the total lipid content of foods.
By comparing the distance that the spots move with standards of known composition it is possible to identify the lipids present.
Lipid oxidation is one of the major forms of spoilage in foods, because it leads to the formation of off-flavors and potentially toxic compounds. Pada hasil ekstraksi akan dihasilkan berupa minyak kemiri yang relative murni Alfin.
This information can be used to: The temperature at which the disc changes shape to a sphere is called the “Wiley melting point”. The sample preparation required in lipid analysis depends on the type of food being analyzed e.