William Hargis
C127
March 13, 2014
Separation and Analysis of Milk
Objective:
This experiment employs techniques of natural product separation and basic biochemical qualitative analytical tests in order to identify, separate, and analyze the major components of whole milk.
Introduction:
Milk is a natural biological product with a complex chemical makeup1,2, it is a colloid consisting of proteins, carbohydrates, fat, vitamins, and minerals. The proteins found in milk are largely water-soluble due to amine and carboxylic acid side chains, amine’s are protonated, and thus positively charged, at a pH near that of 7.44 or human physiological pH2. Amine’s remain unprotonated at high pH2. Carboxylic acids, however, are protonated at low pH and unprotonated at higher pH, such as physiological pH2. Carboxylic acids retain a negative charge in their unprotonated state, at physiological pH carboxylic acids are negatively charged side chains. While the protein retains positively or negatively charged side chains it is water-soluble2. Taking advantage of the isoelectric point by raising the pH to the point that the protein’s charges are balanced results in a loss of solubility, causing the precipitation of the proteins2. The most abundant proteins in milk are water-soluble protein molecules referred to as caseins, the caseins may be precipitated out of the milk by reaching their respective isoelectric point via a change in pH via the addition of an acid, this experiment used acetic acid to lower the pH to approximately 4.6. Butterfat is also precipitated by this change in pH. The resulting solution is precipitated casein and butterfat within a watery solution referred to as whey, the whey contains water soluble proteins that do not precipit...
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...cium tests confirmed the presence of phosphate and calcium, respectively, within the liquid whey filtrate, this was as expected, as the metal ions are water-soluble. The positive Biuret’s Protein Test confirmed that the solid curds contains proteins, this is as expected as the curds should consist primarily of insoluble casein proteins. The butterfats when added to water were found to be non-miscible, indicating that the substance is a non-polar hydrophobic material, this confirms that the butterfats consist of the non-polar fat molecules. The outcomes of these qualitative tests and observations strongly indicates a successful separation of the natural product, whole milk.
Conclusion:
The separation was successful and produced separated stages consistent with prediction based upon solubility properties. This was indicated by the qualitative tests and observations.
However, once it reaches 70% of concentration, the enzyme becomes saturated, meaning that there are no active sites for the substrates to fill, which leaves casein (milk) molecules suspended in the curd; the saturation point for this curve was located at 6.5x 10-3 seconds. This was clearly evident in some of the visual results of the practical, where we could see that there was still milk that could be decanted when the curd was poured out. Therefore, even if we added more casein substrate, the curve enzyme activity would still flatten, indicating again that all or most of the active sites of the renin enzyme were full.
The affects of pH, temperature, and salt concentration on the enzyme lactase were all expected to have an effect on enzymatic activity, compared to an untreated 25oC control. The reactions incubated at 37oC were hypothesized to increase the enzymatic activity, because it is normal human body temperature. This hypothesis was supported by the results. The reaction incubated to 60oC was expected to decrease the enzymatic activity, because it is much higher than normal body temperature, however this hypothesis was not supported. When incubated to 0oC, the reaction rate was hypothesized to decrease, and according to the results the hypothesis was supported. Both in low and high pH, the reaction rate was hypothesized to decrease, which was also supported by the results. Lastly, the reaction rate was hypothesized to decrease in a higher salt concentration, which was also supported by the results.
To uncover organic compounds like carbohydrates, lipids, proteins and nucleic acid, by using tests like Benedict, Lugol, Biuret and Beta Carotene. Each test was used to determine the presents of different organic molecules in substances. The substances that were tested for in each unknown sample were sugars, starches, fats, and oils. Moreover, carbohydrates are divided into two categories, simple and complex sugars. Additionally, for nonreducing sugars, according to Stanley R. Benedict, the bond is broken only by high heat to make make the molecules have a free aldehydes (Benedict). As for Lipids, there are two categories saturated and unsaturated fats. One of the difference is that saturated fats are mostly solids and have no double bond (Campbell Biology 73). The Beta Carotene test works by dissolving in a lipid, thus giving it color to make it visible. Moreover, proteins are made out of amino acids that are linked by a polypeptide bond (Campbell Biology 75). The purpose of this experiment was to determine whether an unknown class sample or food sample had any carbohydrates, lipids, or proteins in it. The expected result of the lab was that some substances would be present while other would be absent.
While the tube for specimen Cb turned a tannish white in the lower half of the tube while the top stayed the lavender inoculated tube color. Do to this evidence I determined that both specimens Ca and Cb cannot use the process Casein hydrolysis or Casein coagulation due to lack of soft or firm curds in both tubes. Since there was no casein curds formed, I concluded that specimens Ca and Cb also cannot perform the process of proteolysis. My conclusion is supported by the fact that there was no clearing of the medium. I have also determine that neither of my organisms can make the enzymes rennin, proteolytic or even proteases. I know my specimens cannot produce proteases due to the fact that there was no blue coloring in the tubes which means that the byproduct Ammonia was not produced to increase the pH. Since neither of my specimens can make these enzymes, I concluded that my specimens cannot break down lactose or casein. Although I did learn that specimen Cb can reduce litmus due to the evidence that the lower part of the tube turned a tannish white color with a purple ring at the top. This color change from a purple to a white means that the litmus was reduced turning it clear and leaving the white of the milk to show. Finally I know that specimen Ca cannot reduce litmus due to the fact that the tube had no change in
The objective of this experiment was to perform extraction. This is a separation and purification technique, based on different solubility of compounds in immiscible solvent mixtures. Extraction is conducted by shaking the solution with the solvent, until two layers are formed. One layer can then be separated from the other. If the separation does not happen in one try, multiple attempts may be needed.
... determine lactose levels. Maybe a lactose quotient could be developed and printed on lactose based products to indicate their relative impact on lactose intolerant people. I think this would be a valuable service to lactose intolerant people in choosing products that contain considerable lactose but have different digestibility factors because of lactase or other additives. I believe study should focus on two major areas. First, alternate methods of processing milk products should be explored, such as making yogurts, cheeses and low-lactose products, and adding lactase to unadulterated milk products to help lactose digestion. Second, alternatives to foods containing lactose should be studied and promoted. This is especially important in food relief programs where our current efforts of sending high- milk diets to hungry people seem wasteful as well as dangerous.
In osmosis, the proteins only on the surface are called peripheral proteins, which form carbohydrate chains whose purpose is used like antennae for communication. Embedded in the peripheral proteins are integral proteins that can either be solid or have a pore called channel proteins. -11.07% Discussion The chart shows the percent sucrose solution that resulted in the greatest change in average egg mass was the 0% solution, while the 1.73% solution resulted in the least change. The data also suggest that the percent sucrose solution that is isotonic to an egg’s interior may be between -10% and -15%, since the average masses of the eggs did not change beyond 0.15% over a 30 minute time period. In fact, the control group displayed the least amount of change in mass (0.10%) over a 40 minute period of time.
Once the mixture had been completely dissolved, the solution was transferred to a separatory funnel. The solution was then extracted twice using 5.0 mL of 1 M
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
Milk Milk is an almost complete food. It consists of proteins (mainly casein), salts, fat and milk sugar, or lactose. It also contains vitamins A, C, D, certain B vitamins, and small amounts of others. Factors That May Affect The Reaction Ø The concentration of Rennin Ø
What Makes Human Milk Special? (Mar-Apr 2006). New Beginnings Vol. 23 No.2 , pp 82-3.
Although the milk itself does not have a very long life, other foods and some dairy products can be made using it. Cheese would be the main example of this, which can be produced simply by the curdling of milk. Rennin, found in the substance rennet, is a milk-coagulating enzyme capable of assisting in the production of cheese. Therefore the temperatures at which the milk and rennet coagulate best at in this experiment, are
The purpose of this experiment was to study the reactions of amino acids and aspartame. Several solutions were prepared and used in TLC analysis. A permanganate test and a ceric nitrate test were also performed. The summary of the results is shown below.
Milk is one of the most nutritionally complete natural foods. It adds high quality proteins, fats, minerals and vitamins to our diet. However, when this milk is handled improperly the bacteria present in milk can multiply and make the raw milk potentially dangerous. Our environment is full of microorganisms that can enter milk during the milking process when the equipment used for milking, transportation and storing milk are not properly cleaned.
Fermentation is an anaerobic metabolic pathway used to oxidize NADH into NAD+. Fermentation is used to produce alcoholic beverages such as wine, and acidic dairy products, such as yogurt. In the absence of air, microorganisms called yeast convert sugars to alcohol. According to the book, “During fermentation, electrons are transferred (along with protons) from reduced coenzymes (NADH, NADPH) to pyruvic acid or its derivatives. An essential function of the second stage of fermentation is to ensure a steady supply of NAD+ and NADP+ so that glycolysis can continue. In fermentation, ATP is generated only during glycolysis.”(Tortora).