In the food industry, plant-derived protein, such as soy protein, is being used as an economical replacement for animal-derived proteins, such as whey and casein, but limitations occur due to the functionality and stability of these proteins in different applications (Pasupuleti and Demain 2010). Protein concentrates contain 50-80% protein, while protein isolates contain greater than 90% protein (Hui 2007). Soy protein isolates are utilized in bakery goods to add texture and emulsification properties with minimal change to the color and flavor of the food (Riaz 1999). In addition, the combination of soy protein concentrates and dried whey protein is used in bakery products as an economical replacement for milk (Riaz 1999). Whey and casein, while typically found in milk, can be isolated and utilized in many other applications, such as the branded ingredient Simplesse, a fat replacer (Hui 2007). Simplesse employs microparticulation, during which milk proteins are denatured and folded into smaller proteins that mimic the lubricating nature of lipids (Hui 2007).
The isoelectric pH range for soy protein, during which solubility is minimal and precipitation may occur due to hydrophobic interactions, is between 4.2 to 4.6 (Pabby 2009). The isoelectric pH range for casein is 4.5 to 4.7 (Pabby 2009). After casein precipitates, the remaining supernatant contains the whey proteins, which may be removed through a process called salting-out (Mine and Shahidi 2006). Ammonium sulfate added to the supernatant will dissociate and the ions will interact with the water to alter water’s structure and increase surface tension, leading to the decreased solubility of and precipitation of nonpolar molecules, such as whey proteins (Mine and Shahidi 2006...
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Poklar N, Vesnaver G. 2000. Thermal denaturation of proteins studied by UV spectroscopy. J Chem Edu 77(3):380-2.
Riaz MN. 1999. Healthy baking with soy ingredients. Cereal Food World. 44 (3):136.
Ryan M, McEvoy E, Duignan S, Crowley C, Fenelon M, O’Callaghan DM, FitzGerald RJ. 2008.
Thermal stability of soy protein isolate and hydrolysate ingredients. J Food Chem 108(2):503-10.
Thermo Fisher Scientific Inc. 2011. Protein assay data analysis. Rockford, Ill.: Thermo Fisher Scientific Inc. Available from: http://www.piercenet.com/browse.cfm?fldID=876769DB 5056-8A76-4ED7-480BC9A5AD92. Accessed Nov 20, 2011.
Thompson LD, Dinh T. 2009. Food proteins – protein isolation and thermal stability. FDSC 4303/5305 food chemistry laboratory manual. Lubbock, Tx.: Texas Tech University, Department of Animal and Food Sciences.
The Effect of Temperature on an Enzyme's Ability to Break Down Fat Aim: To investigate the effect of temperature on an enzyme’s (lipase) ability to break down fat. Hypothesis: The graph below shows the rate increasing as the enzymes get closer to their optimum temperature (around 35 degrees Celsius) from room temperature. The enzyme particles are moving quicker because the temperature increases so more collisions and reactions occur between the enzymes and the substrate molecules. After this the graph shows the rate decreasing as the enzymes are past their optimum temperature (higher than). They are getting exposed to temperatures that are too hot and so the proteins are being destroyed.
After finding out that Xanthan Gum and Whey Protein Concentrate were combined in an emulsion that will not destabilize, it was tested at certain temperatures. When this emulsion was tested at 4℃, this emulsion stayed stable. At 12℃, it separated 2 mL. As the temperature got hotter, it separated quicker. At 50℃, it came apart 3 mL. After 15 minutes at 80℃, it had separated all 10 mL. With water at 4℃ the emulsion stayed together the longest.
There are various methods that have been developed over these years to study protein-protein interactions (PPIs). PPI plays a big role in the cell-signalling cascade; for instance, dephosphorylation of glycogen synthase by protein phosphatase-1 results in glycogen synthesis. To know whether a specific protein binds to its partner, for example, whether TFIIH interacts with TFIIE or TFIIF to complete the pre-initiation complex in transcription, different methods such as co-immunoprecipitation (co-IP), glutathione-S-transferase (GST) pull down assays, yeast-two-hybrid (Y2H) assays, isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), nuclear magnetic resonance (NMR) spectroscopy and etc. can be use to validate PPIs. Yet, doing one experiment using one method is not enough to validate the PPI between two or more proteins. Factors such as overexpression of proteins and manipulation of the agents used in the experiment could result in a bias data. Thus, the results should be unbiased by incorporating different methods in the experiment to validate the PPI. In this essay, the different methods will be described and the factors that cause the different methods giving rise to different results will be discussed.
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
Norton, M. B, Katzman, D. M, Escort, P. D, Chudacoff, H. P, Paterson, T. G, & Jr. Tuttle, W.M.
Investigating The Effect of Temperature on the Structure of an Enzyme Introduction: For my GCSE Biology assessment I will be investigating the enzyme amylase with the substrate starch. This reaction, which I am going to investigate, is called the protein test for starch. Aim: My intention for this observation is to examine how the enzyme catalyses are affected by changes in temperature. Safety Precautions: In this investigation I am going to make sure that everything is as safe as possible and prevent any accidents from occurring.
Introduction: Within this experiment we wish to facilitate a greater understanding of the concepts of experimental design and quantifying techniques. Specifically, this lab will allow us to gain an enhanced understanding of the isolation of a protein using differential solubility, which allows us to separate and purify various proteins using high concentrations of a specific salt so that they may be studied in great detail. Last week we separated our desired protein using ammonium sulfate. Since we have already extracted the desired protein, we will begin quantifying the amount using the Bradford Protein Assay. Because it is a dye-binding assay, we will use the spectrophotometer to measure the absorbance of various dilutions of a protein: this will comprise our standard curve. We will then compare the absorbance of our extracted protein from l...
By Molecular Approaches." Journal Of Dairy Science 96.8 (2013): 4928-4937. Academic Search Complete. Web. 12 Nov. 2013.
Despite of general properties of enzymes, the properties also varies from where it comes from and how it been produced. For instance, the enzymatic saccharification method in lignocellulosic bioethanol is generated by hydrolyzing cellulose and hemicelluloses. This method gets high attention because of its higher theoretical yield compared to other methods (Taneda et al., 2012). Acremonium cellulolyticus with high activities of cellulase, amylase and pectinase enzymes allow it for the easy separation of solids/liquids in potato pulp, resulting in high saccharification efficiency and a high recovery rate of products (Gao et al., 2014). On the other hand, Enzyme-modified carboxymethyl starch (ECMS) is beneficial in enhancing water holding capacity, emulsion stability and improving sensory characteristics of sausages with a declined fat content (Luo and Xu, 2011). Lipases and phospholipases of dormant cotton seeds have stability in heat, various media and nature of the hydrolysis of the lipids properties (Rakhi...
Soy is becoming an increasingly popular food commodity in the United States. This plant serves as one of the food industry’s top cheapest products for food manufacturing processes. Soy derives from the soybean, a leguminous plant widely cultivated for its edible seeds. The soybean originated in China, where the plant was widely famed for being used in a variety of foods, especially when acting as an animal protein replacement. During the late 1700s, the soybeans were imported into the United States. At the time, soy’s main purpose was to serve as a cheaper way to feed farm animals. As time progressed, Americans began using soy for their own nutritional benefits. Although many studies prove positive health benefits from this plant, there are lingering concerns pertaining to the safety of soy consumption.
"Building Complete Proteins from Nuts, Grains and Legumes." / Nutrition / Proteins. N.p., n.d. Web. 19 May 2014. .
Stuart, G. L., Moore, T. M., Elkins, S. R., O’Farrell, T. J., Temple, J. R., Ramsey, S. E.,
Thus, this study will put an efforts by producing plant-derived protein to decrease the global demands for FBS and to decrease the number of bovine fetuses required for the production of FBS. It is crucial to conduct a study that is not only able to produce protein hydrolysates from tempeh, but also to increase the growth performance of cells when tempeh hydrolysates is tested on cell culture. It is significant since the tempeh hydrolysates can be a good substitute for animal-derived serum such as fetal bovine serum because it is more ethical, cost-effective and environmental friendliness. In this experiment, tempeh will undergo solvent extraction to produce Then, the protein isolate will be enzymatically hydrolyse to produce peptides. Lastly, tempeh hydrolysate will be tested on human skin fibroblast cell culture and the growth
Margrett, J. A., Daugherty, K., Martin, P., MacDonald, M., Davey, A., Woodard, J. L., & ...
Food manufacturers use chemical in food processing because of huge economical profit. It is always cheaper to make low quality food rather than healthy food. Food manufacturers’ objectives are to find cheap methods to gain higher profit. The application of techniques such as pasteurization, fermenting and pickling are often use in food companies to prevent food from spoiling ahead of time. Their intention is to stock the food for a long period of time without worrying about early deterioration that can lead to major financial loss. Food companies use antibiotics in chicken, and steroids in cow to stimulate their growth. In an experiment, it was shown that injection of growth hormone in cow improves and stimulates milk production (Baldwin, 1995). Companies’...