FS Homework Sheet_ Carbohydrates Polysaccharides (1)

docx

School

University of California, Los Angeles *

*We aren’t endorsed by this school

Course

Subject

Chemistry

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by CorporalTitanium1170

Food Science—Carbohydrate Homework: Polysaccharides Please review the Learning Module on Carbohydrates for further understanding of carbohydrate chemistry. You’ll need to read the Dextrinization and Roux articles to answer questions on dextrinization. Vocabulary 1. Oligosaccharide: A carbohydrate molecule made up of three to ten sugar molecules. Cannot be digested by the body. An intermediate size saccharide linked together with chemical bonds. 2. Polysaccharide: A carbohydrate molecule made up of tens to hundreds to several thousand monosaccharide units linked together in chains. Starch, cellulose and other fibers, and hydrocolloids are all polysaccharides. Higher saccharides with many sugar units; usually between 10 and 2 million sugar units all linked together through chemical bonding. 3. Maillard Browning: A non-enzymatic browning reaction that occurs when reducing sugars interact with amino groups on proteins, ideally with dry heat. A series of complex reactions occur resulting in color and flavor molecules. The sugars must be reducing sugars, or sugars with a carbonyl functional group. Involves the breakdown of sugars, the carbonyl group on a sugar, and the amino group on an amino acid, which are the building blocks of proteins, reacting and creating brown colors and flavors. This reaction takes place at high temperatures, greater than 300F when carbohydrates/sugars and amino acids/proteins are present. 4. Dextrinization: The non-enzymatic process that involves the browning of starch foods when subjected to dry heat. It is the breakdown of starch into dextrins. Starch molecules break into fragments and rearrange themselves to create new flavor and color compounds. Example: roux being cooked to increasingly dark stages. Temperature must reach over 300F, the brown colors and flavors are created only under these conditions. Water must not be present, or the process will not occur properly as the proper temperature cannot be reached. Involves the breakdown of starches at high temperatures greater than 300F. 5. Non-enzymatic browning: A browning reaction that does not involve the use of an enzyme. It is a set of chemical reactions that are responsible for the formation of complex flavor compounds and brown pigment compounds. Examples include Maillard browning and caramelization. 6. Enzymatic browning: An oxidation reaction that requires an enzyme and oxygen and causes various foods to turn brown. This reaction mostly occurs with fruits and vegetables. Examples include the browning of avocado and the browning of an apple when sliced open.

7. Hydrolysis: The use of water, “hydro,” to break, “lyse,” covalent bonds; breaking down organic molecules into their smaller counterparts. The more acid and the longer the heat, the more hydrolysis. The breakdown of higher polymers into monomeric units with the addition of water. 8. Oligomerization: A chemical process in which a monomer or a mixture of monomers is being converted into an oligomer. Part 2: Short Answer 1. Explain the difference between soluble and insoluble dietary fiber. Soluble fiber dissolves in water, it is hygroscopic and slows digestion. It includes plant pectin and gums. Insoluble fiber does not dissolve in water and helps with regularity. It includes cellulose and hemicellulose. Soluble fiber can be hydrated by water; insoluble fiber is packed too tightly for water to get in and hydrate the molecules which makeup the fibrous bundles. Neither kind of fiber can be digested by humans; we do not possess the digestive enzymes necessary to break down fibers into their monomer units. None can be absorbed through the gut and into the blood stream larger than a monomer, with respect to carbohydrates and proteins. 2. Describe Starch Gelatinization: Gelatinization is a physical and chemical process that combines starches and water in the presence of heat. This causes the starch to swell and absorb the water trapping network. The two factors that must be present for starch to gelatinize are 1. Water and 2. Heat. Separating each starch granule into a roux or slurry is crucial to prevent lumps, promote even thickening, enhance solubility, and prevent burning. Dry starch cannot be added to boiling water because there is a risk of lumps, incomplete gelatinization, and inconsistent thickening. When starch granules are in the presence of water and heat, they will begin to absorb water. This causes the starch granules to swell and thicken. As this process is continued and more heat is applied, some granules will burst and release starch molecules into the surrounding medium. Maximum thickening is achieved when the granules are at their maximum swelling, and some molecules have separated from the granule. The separated molecules go on to form a network which traps water and the swollen granules. Thinning can occur if the heating continues, and the granules lose their structure entirely, or “burst.” The thickening power of the sauce is lost from the swollen granules, but will keep thickening because of the starch fractions that have spilled out. a. When answering the question, be sure to include the two factors that must be present in order for starch to gelatinize and… Heat and water. b. Describe why it is important to separate each starch granule from each other before applying heat (why do you need to make a slurry or a roux before heating the starch)? And…

This is important because when heat is applied, the protein coating of the granules begins to become sticky with hydrogen bonds. This causes the granules to stick to each other instead of allowing water to flow into the granule, which is the desired result in order to achieve maximum thickening. c. Why you cannot add dry starch to boiling water. It will clump. 3. Why do you believe it is important to use clarified butter, rather than plain butter, when making a brown roux? Clarified butter is pure butter with the milk solids and water removed. This is preferable because the milk solids can burn before a brown roux is achieved. Whole butter can also cause the starches to gelatinize too early. If water is present the starch will gelatinize too early, the temperature will not be able to get above the boiling point of water, 212F, until all water has boiled off. 4. Describe the difference between Caramelization and Maillard Browning Caramelization is a non-enzymatic browning reaction that occurs when sugar is heated; chemical reactions occur that result in sugar molecules breaking down into smaller fragments. Maillard Browning is also a non-enzymatic browning reaction, but it occurs when functional groups on proteins and sugars interact, and new compounds are created that impart brown colors and complex flavors. Caramelization involves the breaking down of molecules into new molecules, while Maillard Browning involves molecules coming together to form new molecules. 5. Why do you believe that coffee and cocoa roasters keep their roasting process proprietary? The reason coffee and cocoa roasters would keep their roasting process proprietary is because the roasting process is crucial to creating a good product; the coffee/cocoa beans go through many chemical reactions that create new complex compounds, flavors, and aromas. The roasting process is what unlocks these molecules, and it directly impacts the flavor of the final product. The process of roasting is directly related to which flavors develop in the Maillard browning process during the roasting of coffee and cocoa. This becomes the company’s intellectual property. It is proprietary because, similar to a formula, they do not want their competition to know the specific process to achieve the flavors. Part 3: Critical Thinking Describe the difference between a white, blonde, and brown roux: A white roux is cooked for the shortest amount of time and has a neutral flavor. The goal is just to cook out the flavor of the flour, without toasting. It is cooked for about 2-3 minutes. This roux is typically used when making white sauces or milk-based sauces, such as béchamel. A blonde roux has a nuttier flavor compared to the white roux and is cooked for longer than a white roux, but shorter than a brown roux. Blonde roux is cooked for about 4-5 minutes, achieving a slight toasty flavor. A blonde roux would be used in a sauce that has a golden color, such as velouté.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

A brown roux is cooked for the longest amount of time and has the nuttiest flavor out of all the roux. It also has less thickening power than the lighter roux. It is typically cooked for 8-10 minutes, or until a dark brown color is achieved; the nutty aroma is much stronger compared to other roux. Brown roux is typically used for brown sauce preparations such as espagnole and gravy. A new application for a brown roux would be in a classic French Onion Soup. Using a brown roux would enhance the flavor of the final product, and it would work as an effective thickening agent, which would give the soup a smooth and velvety texture. 1. When answering this question, give an example of when each of the above roux is normally used in Culinary applications and…. 2. Suggests a new application for a brown roux and give a detailed explanation of how adding a brown roux would change the flavor and texture of your suggested application.

Related Documents

school 13.png

SCI 100 Module Five Activity Template.docx

Cell Biology Lab.dotx

Unit VI Case Study.docx

psy 5135 week 2 db2.docx

CHEM HONOR WK8.docx

LAB REPORT DATA SHEET_acetylsalicylic acid.docx

DAD220 Mod4-3 Major Activity Database Documentation.docx

Module 1 Quiz.docx

Lab 2 Report 2.pdf

IMG_4113.jpeg

marine_pollution_lab.docx

Recommended textbooks for you

Chemistry for Today: General, Organic, and Bioche...

Chemistry

ISBN:9781305960060

Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. Hansen

Publisher:Cengage Learning

Chemistry

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Cengage Learning

Chemistry: An Atoms First Approach

Chemistry

ISBN:9781305079243

Author:Steven S. Zumdahl, Susan A. Zumdahl

Publisher:Cengage Learning

Chemistry

ISBN:9781133611097

Author:Steven S. Zumdahl

Publisher:Cengage Learning

Introductory Chemistry: A Foundation

Chemistry

ISBN:9781337399425

Author:Steven S. Zumdahl, Donald J. DeCoste

Publisher:Cengage Learning

Chemistry: Matter and Change

Chemistry

ISBN:9780078746376

Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl Wistrom

Publisher:Glencoe/McGraw-Hill School Pub Co

SEE MORE TEXTBOOKS

Recommended textbooks for you

Chemistry for Today: General, Organic, and Bioche...
Chemistry
ISBN:9781305960060
Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. Hansen
Publisher:Cengage Learning
Chemistry
Chemistry
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Cengage Learning
Chemistry: An Atoms First Approach
Chemistry
ISBN:9781305079243
Author:Steven S. Zumdahl, Susan A. Zumdahl
Publisher:Cengage Learning
Chemistry
Chemistry
ISBN:9781133611097
Author:Steven S. Zumdahl
Publisher:Cengage Learning
Introductory Chemistry: A Foundation
Chemistry
ISBN:9781337399425
Author:Steven S. Zumdahl, Donald J. DeCoste
Publisher:Cengage Learning
Chemistry: Matter and Change
Chemistry
ISBN:9780078746376
Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl Wistrom
Publisher:Glencoe/McGraw-Hill School Pub Co