Baking Science and Ingredients Quiz

Course Information

• Course: NUT 1104 Food Sciences I
• Term: 2024 Fall
• Instructor: Ezgi Pulatsu, Ph.D.
• Department: School of Nutrition Sciences
• University: University of Ottawa/Université d'Ottawa

Course Content

• Module 1: Introduction
• Module 2: Food Components and Chemistry (water, carbohydrates, proteins, lipids, vitamins, and minerals)
• Module 3: Food and Food Materials (meat, poultry, fish, eggs, dairy, legumes, pulses, cereals, flour, pasta, bread, baked goods, and chocolate)
• Module 4: Food Additives and Food Safety

Course Calendar

• Week 1 (9/17/2024): Introduction to the course
• Week 2 (9/24/2024):
  • Lecture 1: Water and Introduction to Carbohydrates
  • Lecture 2: Carbohydrates: nomenclature, structure, and chemistry
• Week 3 (10/1/2024):
  • Lecture 3: Proteins: nomenclature, structure, and chemistry
• Week 4 (10/8/2024):
  • Lecture 4: Lipids: nomenclature, structure, and chemistry
• Week 5 (10/13-10/19): Reading Week (no class)
• Week 6 (10/22/2024):
  • Lecture 5: Vitamins and Minerals
• Week 7 (10/29/2024):
  • Lecture 6: Meat, poultry, fish, eggs, and dairy
• Week 8 (11/5/2024):
  • Lecture 7: Legumes, pulses, cereals, flour, and pasta
• Week 9 (11/12/2024):
  • Lecture 8: Bread and baked goods + Dairy Farm Virtual Tour
• Week 10 (11/19/2024):
  • Lecture 9: Chocolate
• Week 11 (11/26/2024):
  • Lecture 10: Food Additives
  • Lecture 11: Food Safety
• Week 12 (12/3/2024): Final Exam Review
• Dec 17th/19th/20th: Final Exam, Deferred Exam Dates (Dec 19th 9:00 am-12 pm & Dec 20th 9:00 am-12 pm)

Recommended Readings

• Book 1, Chapter 2 (pp. 21-29)
• Book 2, Chapter 3 (pp. 91-150) etc...

Learning Outcomes

• Become familiar with the physics and chemistry of bread and baked goods
• Understand the reactions and importance of formulations
• Identify the manufacturing steps and processes

Outline (Bread and Baked Goods)

• Physics and chemistry
• Roles of ingredients in the mix
• Quality attributes

Other Information

• Canada is the 12th largest retail market for bakery products in the world
• Retail sales of baked goods are expected to grow 3.5% from 2022 to 2026, reaching US$7.8 billion by 2026.
• Canada was the world's second largest exporter of baked goods in 2021 (after Germany)
• The largest bread market player in 2021 in Canada was George Weston Ltd., with US$787.0 million in sales
• Supermarkets account for 47.8% of the market with $3.1 billion in sales.

Introduction: Additional Points

• Use of carbohydrates, fats, and proteins
• Functionalization of ingredients
• Use of sugar, fat, and flour
• Ratio, measurements, instructions in recipes
• "Culinary Alert": instructions in recipes often require specific procedures (e.g., sifting flour before measurement)
• Batters and dough characteristics
• Kneading and mixing
• Leavening agents

Batters

• Pour batters (pancakes, popovers): 1:1 ratio of liquid to flour
• Drop batters: greater flour content than pour batters;1:2 ratio of liquid to flour (e.g., muffins, cookies)

Dough

• Thicker than batters
• Less liquid than batters
• Kneaded, not beaten or stirred
• Continuous medium: the flour/gluten matrix

Table 15.1 (Batter/Dough Types)

-Indicates the ratio of liquid to flour for various types of batter and dough.

Gluten

• Heterogenous mixture of gliadins and glutenins
• High in glutamine
• Low in essential amino acids (lysine, methionine, tryptophan)
• Insoluble in water (but it does absorb water)
• Heat-sensitive
• Gluten-forming proteins in wheat

Gluten Matrix

• Strong, three-dimensional, viscoelastic structure
• Hydrophobic, insoluble gliadin protein contributes to sticky, fluid properties in dough.
• Insoluble glutenins contribute to the elastic properties in dough.
• Requires hydration

Gliadins

• Contain single polypeptide chains
• Globular conformation with intra-disulfide bonds
• Low molecular weight (16 kDa - 50 kDa)

Glutenins

• One group: low molecular weight (20 kDa - 50 kDa)
• Another group: high molecular weight (50 kDa - 200 kDa)
• Important for human nutrition but linked to illnesses (gluten sensitivity, celiac disease, food allergy)

Gluten Network Formation

• Physical and chemical transformations take place upon hydration and manipulation
• Hydrogen bonding, hydrophobic association, disulfide crosslinking
• Applied shear and tensile forces

Importance of Gluten Network

• Dough properties (viscoelasticity, strength, resistance) depend on the structure and interaction of proteins.

Types of Interactions in Gluten Network

• Peptide bonds
• Van der Waals interactions
• Ionic interactions
• Disulfide bonds

Factors Disrupting Gluten Network

• Presence of fat
• Presence of fiber or compounds competing with water absorption
• Presence of acid

Functions of Gluten Proteins in Dough

• Gliadin responsible for extensibility and viscosity
• Glutenin linked to strength parameters (elasticity, cohesiveness)
• Gluten network slows down water transfer, maintaining gas production during yeast fermentation

Bread and Baked Goods

• Encourage gluten network formation (bread, strudel dough)
• Inhibit gluten network formation (cakes, biscuits)

Modifying Dough Properties

• To make dough stronger: add salt, use high gluten flour
• To make dough weaker: add sugar, add fats/oils, increase acidity in dough

Flour Types

• High gluten flour produces stronger dough

Experiment on Gluten Content

• Image depicting the different qualities of gluten balls made from different types of flour

Functions of Ingredients

• Flour: provides structure (mostly due to the protein gluten, to a lesser degree with starch content)
• Liquids: provides hydration for protein and gluten formation, also for starch gelatinization; acts as a solvent to facilitate the solubility of other ingredients, and creates steam
• Leavening agents: chemical, biological, and physical agents, to raise the dough with air, CO2, and steam
• Egg: acts as a binder to hold ingredients together, distributes fat, contributes to aeration, structure, color, and flavor.
• Fats/oils: tenderize baked products, shorten (control gluten strand length), leaven dough by incorporating air (creaming solid fats with sugar, contribute flakiness, and help prevent staling), plastic fats (e.g., hydrogenated shortening or some other solid fats)
• Salt: necessary component for yeast bread by dehydrating yeast cells, controlling their growth, contributes to flavor, competes with other substances for water (affecting gluten development and starch gelatinization, exerts osmotic effect;
• Sugar: contributes to flavor, tenderizes products, competes for water (affecting starch and protein development), elevates coagulation temperature of proteins and starch gelatinization, acts as a substrate for yeast to work; exhibits hygroscopic (moisture-retaining) properties; affects the final texture of the baked products (moist, gummy or runny). Sugar browning caused by Maillard reaction or sugar caramelization.

Class Activity

• Read the article and answer questions posted by the professor on Brightspace

Next Topic

• Chocolate (module 3.6)