Most amino acids exist as isomers and are given a designation based on whether they rotate a plane of polarized light to the right or to the left, known as dextrorotatory “D” or levorotatory “L” isomers, respectively (Al-Holy and Rasco 2007). It should be noted that only L amino acids are used in protein synthesis (Weber and Miller 1981).
The biological functions of proteins include increasing the rate of biochemical reactions in the form of enzymes, moving important substances to where they are needed in the form of transport proteins, regulating the body in the form of hormones, allowing the body to move in the form of contractile proteins, and providing support in the form of structural proteins (Reece and others 2011).
In addition, proteins have a great deal of functionality in foods, including providing essential amino acids as well as energy, viscosity, texture, water holding capacity, foaming and emulsification properties, and allowing gel formation (Culbertson 2007). As mentioned above, essential amino acids provided by th...
... middle of paper ...
Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. 2011. Campbell biology. 9th ed. San Francisco: Cummings-Pearson. 1263 p.
Siegwein AM, Vodovotz Y, Fisher EL. 2011. Concentration of soy protein isolate affects starch-based confections’ texture, sensory, and storage properties. J Food Sci 76:E422-8.
Sorgentini DA, Wagner JR, Anon MC. 1995. Effects of thermal treatment of soy protein isolate on the characteristics and structure-function relationship of soluble and insoluble fractions. J Agric Food Chem 43:2471-9.
Thompson LD, Dinh T. 2009. Food proteins-protein isolation and thermal stability. FDSC 4303/5303 food chemistry laboratory manual. Lubbock, Tx.: Texas Tech University, Department of Animal and Food Sciences.
Weber AL, Miller SL. 1981. Reasons for the occurrence of the twenty coded protein amino acids. J Molecular Evolution 17:273-84.
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- Isolation techniques for protein take the least refined forms of the protein and develop a highly concentrated product. A concentrated protein product allows utilization of functional properties of proteins without fat, moisture, or carbohydrate contributing to or inhibiting the system. For example, through the use of isolation techniques, the starting concentration of soy flour or grit, 40-50% protein, can increase to more than 90% (Petruccelli 1995). When other substituents such as starches and fats are present in a system, water absorption generally occurs within the carbohydrate instead of the protein (Wolf 1970).... [tags: Research Analysis, Isolation Technique]
972 words (2.8 pages)
- Proteins are organic polymers made up of chains of amino acids and are crucial material in many biological functions (Reece and others 2011). There are twenty basic amino acids, eight of which are essential to the adult human diet and must be consumed rather than synthesized inside the body. These essential amino acids are isoleucine, leucine, tryptophan, lysine, valine, phenylalanine, methionine, and threonine, with an added requirement of histidine in the diet of children (Potter and Hotchkiss 1995).... [tags: Scientific Research, Amino Acids]
1598 words (4.6 pages)
- 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).... [tags: Scientific Research, Food Industry]
1394 words (4 pages)
- The structure, composition, and chemistry of proteins play an important role in how they function both in food systems and in the human body (Al-Holy and Rasco 2007). Proteins are comprised of chains of amino acids ranging from 50 to 5000 amino acids, often covalently bonded to other chains of amino acids to comprise its quaternary structure (Salway 2004). For example, all proteins contain an independent-R group, an amine group, and a hydroxyl group (Al-Holy and Rasco 2007). Amino acids are essentially zwitterions because they contain both an acidic and basic groups (positive and negative charges) which makes them amphoteric (Salway 2004).... [tags: Scientific Research, Amino Acids]
2012 words (5.7 pages)
- Proteins have an important role in the nutritional, structural, chemical and functional properties of food. The food proteins provide the essential amino acids, which are needed for growth and various metabolic pathways (Murad, 2007). Proteins are made up of carbon, hydrogen, nitrogen, oxygen and/ or sulfur (Barret, 1985). Proteins present in dairy products have a significant impact on the flavor profile of the products. Milk proteins are used to improve the smoothness, whippability and texture of frozen dairy desserts (Damodaran, 1997).... [tags: Food Science]
1717 words (4.9 pages)
- Proteins can be defined as major biological macromolecules that are important to cellular metabolism and mediation of nearly all molecular transformations (Voet and others 2001). Protein structure is non-uniform due to the widely variable chemical and physical properties of the twenty amino acids that comprise proteins (Voet and others 2001). Since proteins are defined as polymers of other units, proteins may then be further described by the structural levels in which they are organized. Proteins may be organized into primary, secondary, tertiary, and quaternary structures.... [tags: Scientific Research ]
1515 words (4.3 pages)
- Proteins are amazing chemical polymers. They serve a myriad of functions such as providing nutrition in the form of their constitutive amino acids as well as energy. They serve as reactants and enzymes in chemical reactions. Proteins contribute to the texture, viscosity and water holding capacity of foods that contain them. Proteins can be toxins or allergens or hormones, and they serve as transporters for vital molecules such as oxygen in the blood stream (Coultate 1984). These polymers have evolved to play a role in very specific physiological functions and this chemical reactivity can be used for very unique applications beyond a proteins evolutionary scope.... [tags: Scientific Research, Soy Proteins]
2322 words (6.6 pages)
- Proteins are an essential to food as they contribute greatly to the physical properties of food through their ability to build or stabilize fibrillar structures, foams, emulsions, and gels (Belitz and others 2004). Additionally, they are the precursors for aroma and color compounds that are formed during enzymatic or thermal reactions during production, process or storage. Damodaran (1996) states that food proteins can be defined for practical purposes, as those proteins that are easily digestible, are non-toxic, abundantly available, functionally usable in food products, and are nutritionally adequate.... [tags: Scientific Research ]
1999 words (5.7 pages)
- Introduction Foods are complex systems composed of different components, among which proteins play important roles in the structure, texture, and stability of many foods (Hemar and others 2001). Protein isolates and their concentrated products are commonly and widely used in the food industry for both their added functionality and their nutritive contributions. The functionality of ingredients is important in preparation, processing, storage, quality and sensory attributes of foods (Culbertson 2007).... [tags: Nutrition ]
1544 words (4.4 pages)
- The primary goal of this research-inspired laboratory experience is to integrate genuine research into the biochemistry laboratory course for undergraduate students. This course introduces students to resources available to them via the Internet as well as standard experimental approaches and techniques used in modern biochemical research, through hands-on experimentation, discussion and application. Techniques will include bioinformatics tool, DNA purification and analysis, protein purification and quantification, enzymatic characterization, chromatography, electrophoresis, and spectroscopic analysis.... [tags: Protein, Amino acid, DNA, Acid]
1076 words (3.1 pages)