Grease spot test is one of the tests for lipid identification. The working principle is that most lipid or grease are non-volatile due to their high boiling point. In room temperature, the water spot will disappear because water can absorb enough heat from the surrounding air and evaporated. But, the lipid spot can never absorb enough heat to evaporate and hence the lipid will stuck inside the paper sheet. Thus, lipid diffracts the light ray so that light can pass from one side of the paper to another side. This gives the phenomenon of "translucent". In practical 8.1, water gives a negative test whereas both corn oil and olive oil give a positive test which is indicated by the formation of translucent patches on the paper. For food sample, full cream milk and ground nut show a positive result with the presence of lipid while rice gives a negative result with the absence of lipid. Lipids are predominantly composed of …show more content…
Acrolein is the simplest unsaturated aldehyde that produced widely but is most often immediately reacted with other products due to its instability and toxicity. When a fat is heated strongly in the presence of a dehydrating agent such as potassium bisulfate (KHSO), the glycerol portion of the molecule is dehydrated to form the unsaturated aldehyde, acrolein which has the odour peculiar to burnt cooking grease. Further heating results in polymerization of acrolein, which is indicated by the slight blackening of the reaction mixture. In practical 8.4, corn oil, olive oil, full cream milk and ground nut show positive test with both the rancid burnt grease smell and the black colour sample formed that indicate the presence of glycerol or fat. Only rice shows negative test with un-rancid caramel-like smell and the formation of little black solid. Student are strictly have to be extra careful when heating the sample such as using the test tube holder to hold the test tube and not by bare
The boiling point of the product was conducted with the silicone oil. Lastly, for each chemical test, three test tubes were prepared with 2-methylcyclohexanol, the product, and 1-decene in each test tube, and a drop of the reagent were added to test tubes. The percent yield was calculated to be 74.8% with 12.6g of the product obtained. This result showed that most of 2-methylcyclohexanol was successfully dehydrated and produced the product. The loss of the product could be due to the incomplete reaction or distillation and through washing and extraction of the product. The boiling point range resulted as 112oC to 118oC. This boiling point range revealed that it is acceptable because the literature boiling point range included possible products, which are 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane, are 110 to 111oC, 104oC, and 102 to 103 oC. For the results of IR spectroscopy, 2-methylcyclocahnol showed peaks at 3300 cm-1 and 2930 cm-1, which indicated the presence of alcohol and alkane functional group. Then, the peak from the product showed the same peak at 2930 cm-1 but the absence of the other peak, which indicated the absence of the alcohol
The unknown substance is probably a carbohydrate because it tested positive for starch which is a polysaccharide. This reaction also had very similar results as the Lugol’s test for potatoes which is a polysaccharide. Although the colors from the test for potatoes were not the same colors as the test for the unknown; the Biuret test had a slight color change and the Lugol’s test had a dramatic color change for both the unknown and potatoes. I am sure that the unknown was a starch, but the Benedict’s test for sugar was positive for the potatoes while the Benedict’s test for the unknown didn’t have a color change. The unknown probably did not have a color change for the Benedict’s test simply because there were not enough sugar present in the unknown for it to test positive. The Sudan IV Test for Lipids did not test positive for the unknown nor the potatoes because there isn’t a trace of lipids in starch. Based on my results, the unknown has a little protein, a lot of starch and no traces of lipids or
Acid or base-catalyzed hydrolysis yields the component fatty acid, some examples of which are given in the following table, together with the alcohol component of the lipid. These long-chain carboxylic acids are generally referred to by their common names, which in most cases reflect their sources. Natural fatty acids may be saturated or unsaturated, and as the following data indicate, the saturated acids have higher melting points than unsaturated acids of corresponding size. The double bonds in the unsaturated compounds listed on the right are all cis (or
After that bolt the slide dry with bibulous paper. After that examine the slide under the oil immersion lens. After determining the Gram stain reaction, 18 specific biochemical tests were performed for further analysis. The way of biochemical test was different but need to incubate at 37 degree Celsius. Phenol red lactose, phenol red dextrose, phenol red sucrose, methyl red, voges-proskauer, citrate utilization test, urea hydrolysis, and nitrate reduction are the media which are in test tube as liquid. Which were use Inoculating loop to deep tube with assigned bacteria. Triple sugar iron, and citrate utilization are in slant and we use Inoculating needle to deep tube with assigned bacteria. Again, starch hydrolysis, casein hydrolysis, lipid hydrolysis, oxidase test and catalase test were test from agar plate which use inoculating loop. For those media, which were in agar plate, inoculate with loop by making a line streak down the center of the agar. After that all 18 medias need to incubate at 37 degree Celsius for 48 hours. After 48 hours, some media show bacteria’s characteristics and morphology without adding extra reagent. Some media need reagent to examine morphology and physiology. Experiment such as MRVP needs methyl red, Barritt’s A, and Barritt’s
and the best bit of the film is that it is a mix of genre so it suits
All creatures provide themselves with fatty foods because lipids are important when storing energy for long periods of time. An example on how to test for lipids (or fats and oils) is to simply rub or brush the sample on a piece of wax paper and let the paper dry. Once the paper is fully dry, a greasy or oily stain will show up when paper is dry and held up to the light. Beef, potatoes, and other deep fried or greasy foods showed up well on the wax paper.
Food additives are substances that are added to food to enhance it; they can be both chemical and natural ("Food Additives: MedlinePlus Medical Encyclopedia"). Recently many food additives have been questioned by both the public and scientists world wide. One example of the food additives that have been studied is sodium stearoyl lactylate. It has recently been looked at due to indications that it might be unsafe for consumption. In this essay a couple main points and questions will be explained; what is sodium stearoyl lactylate, what are its effects both positive and negative, what are some indirect effects SSL has on society, is it ethical to use, and if sodium stearoyl lactylate safe for human consumption.
0,74 0,87 1,00 0,49 100... ... middle of paper ... ... some groups had got different leakage of the pigment in the test tubes with water.
In order to identify the presence of lipids in these samples, we use the Sudan IV solution. If the unknown A, B, C milk samples turn from clear to dark pink color
For my film project, I will be exploring the film, Grease (Carr & Kleiser, 1978). This film is about an American teenage couple who fall in love over the summer, but unexpectedly reunite at high school. The girl, Sandy, must adapt to the social hierarchy of the public-school system since she is a new exchange student. Throughout the film, the couple tries to find their identity and test the social rules you find in high school romances, friends, and experiences. I chose this film because it is a classic movie, entertaining, and accurate representation of certain anthropological concepts. I think Grease (Carr & Kleiser, 1978) is a good movie to view from an anthropological perspective on many topics such as acculturation, ethnocentrism, and
Once reaching a constant mass after driving of the excess diethyl ether, the crude product had a mass of 0.327grams and a high percent yield of 97.8%. During the first TLC examination of the crude product it was found to have 3 spots on the plate, biphenyl, benzaldehyde, and benzhydrol with Rf values of 0.68, 0.36, and 0.10 respectively. It was expected to see benzhydrol, the product, and biphenyl, the impurity, on the plate, but the presence of benzaldehyde was telling that not all of the starting material had been consumed during
Good fats come from vegetables, nuts, seeds and fish. The two broad categories of beneficial fats include monounsaturated and polyunsaturated fats. The good healthy fats are liquid at room temperature, and do not solidify. They are different from saturated fats as that have fewer hydrogen atoms bonded to their carbon chains.
HPLC (High Performance Liquid Chromatography) is an analytical technique which separates a complex mixture of components into its specific individual components. It is a powerful tool in analysis, as it combines high speed with extreme sensitivity compared to traditional methods of chromatography because of the use of a pump which creates a high pressure and forces the mobile phase to move with the analyte in high speed. It is been used as a principle technology in various automated analyzers used for diagnostic purpose.
Nutrients are the chemicals that humans need to live and grow. Humans obtain their nutrients from the food and water that they drink. They are used to build and repair tissues and regulate body processes and are converted to and used as energy. Lipids are a category of nutrients. Lipids consist of fats, oils, and waxes and are very important for are body’s health. Lipids are important for the human body because they are for storing energy, they’re good at storing energy because they can concentrate a group of calories in a smaller area.
Structure and Biological Significance of Lipids Lipids are made up of a wide variety of molecules, but they all contain carbon, hydrogen and oxygen, with a much higher percentage of carbon and hydrogen molecules than oxygen. There are three kinds of lipids in living organisms: triglycerides, phospholipids and steroids (hormones). Triglycerides are made up of a glycerol molecule, with three fatty acid chains attached by ester linkages. Glycerol is an alcohol containing 3 carbon atoms. The fact it is an alcohol means it has an -OH group at one end.