Midterm 3, Nutrition 108A

Chemical Leavening: Double Acting Baking Powder

- 2 acid acting ingredients (may be one acid released in 2 parts) - Produces 2 stages of CO2 release 1. In dough by cold H2O. 2. During baking (heat)

POLYSACCHARIDES

- >10 units - Affects water movement by hydrogen bonding = Water trapper - Contributes to flavor and texture of products

Eggs in Baking

- Also acts as a liquid - Coagulation of proteins --> texture (egg foams) - Yolk= emulsifier

Aluminum Free Double Acting Baking Powder

- Aluminum is not always desired - Flavor - Negative health effects? - Instead, monocalcium phosphate is treated to release gas in cold water and when heated.

Chemical Leavening: Baking Soda

- Baking soda (sodium bicarbonate) acts as base - Need to add an acid and both must be in solution. - Common acidic ingredients: -soured dairy products -honey, molasses, fruit juice -cream of tartar - Limitations: -Reaction occurs very quickly: need to bake immediately -Excess acid results in Na2CO3 production --> soapy flavor, yellowish color - Inconsistent outcome

Wheat Flour Fat

- Content is low (1-2 %) -Whole wheat: 2% -Germ is removed during refining - Rancidity: whole wheat flours -Lipase action on glycerides can cause rancidity from free fatty acids -Lipoxidase creates oxidative rancidity by generating peroxides from fatty acids - Includes phospholipids that help prevent rigid aggregation and rupture of gluten

GLUTEN-FREE ALTERNATIVES

- Do not produce gluten - Proteins cannot provide structural support similar to gluten - Starch may have different capabilities for water-holding capacity - Nutritional content varies -May have additional additives

Fats in Baking

- Flavor - Texture, flakiness - Inhibits gluten development -shortening - Flaky structure, steam from butter

Chemical Leavening: Single (Fast) Baking Powder

- Includes an acid that dissolves readily in cold H2O (like cream of tartar) - Essentially the same as baking soda + acid but measured quantities for neutralization - Disadvantages: - Requires fast preparation and immediate baking

Factors Influencing Gluten Development

- Increased temperature increases rate of gluten development -Rate of protein hydration is accelerated - Sugar retards gluten development -Hygroscopic, competes for water - Lipids in flour are necessary for gluten development, but increased fat delays gluten development -Coats proteins preventing water access - Excess water decreases gluten development -Dilutes protein and prevents interactions

MODIFIED STARCHES

- Modified from it's native state by chemical or physicalmeans¡ - "Waxy" usually contain 0% amylose - Pre-gelatinized starches: starches have been gelatinizedand then dehydrated - "instant" gelation - Cold-water swelling = pregelatinized -cornstarch slurry

Chemical Leavening: Baking Powder

- Sodium bicarbonate powder mixed with dry acid salts and corn starch -Cornstarch absorbs water to prevent reaction and extend shelf life. -Also, acts as filler for volume standardization. - Single vs. double acting - More consistent product

Liquids in Baking

- Solvent to dissolve sugar, baking powder, salt - Starch gelatinization - Steam leavening - Gluten development - Crust browning (milk)

POLYSACCHARIDES: STARCH

- Storage form of energy in plants - Very large chain of glucose molecules - amylose - Amylopectin - Deposited in tiny, solid granules

Salt In Baking

- Strengthens gluten network -balances charges and prevents repulsion -makes dough more elastic - Flavor -Subthreshold taste

Sugar in Baking

- Sweetener - Browning crust -caramelization and Maillard reaction - Retards protein coagulation, ↑ volume - Retards gluten development -hygroscopic

POTENTIAL ISSUES FOR GELATION

- Syneresis - with time, amylose molecules draw together and free waterseeps out - Retrogradation - rearrangement of amylose molecules into morecrystalline structure - Results in grittier texture, decreases quality - Can be undone with gentle heating - breaking amylose hydrogen bonds and allowinggelling process to happen again - examples: old bread, puddings and gravies held in fridge for days

CONTROLLING YEAST FERMENTATION

- Time (dough rests) - Temperature¡ -Ideal: 25-27.7°C (77-82°F) -Maximum temperature ~35°C -What happens when the temperature exceeds this maximum? - Sugar and Salt Amount - pH -S. cerevisiae: pH 4-6 -S. exigus & S. inusitatus: pH ≤ 4.5. -Lactobacillus sanfranciscensis → lactic acid (lowers pH) -Amylase more active at lower pH

STARCH IN RICE

- When starch is heated it becomes viscous - Upon cooling, amylose molecules (and linear parts of amylopectin) line up and formhydrogen bonds¡ - This crystalline structure is called resistant starch - RS is not digested and absorbed in the small intestine -It can be broken down by bacteria in the large intestine -Could reduce energy availability by 50-60% -Cooked and cooled potatoes -Green bananas

Physical Leavening: Steam

- Whenever water is present, steam is formed. - Steam provides 2-3X as much leavening as air. - Equal amounts of liquid and flour favor steam formation - High heat -->rapid generation of steam

FIBER

- Whole, plant-based foods - Provide texture - Humans do not have enzymes to digestfiber, pass through GI tract unchanged - No calories - any health benefits

STARCH GRANULES

- rings of amylopectin interspersed with amylose - both present - different plants: different sizes - rice= smallest - potato= largess - swell when heated with water

POLYSACCHARIDE EXAMPLES

- starch - glycogen - cellulose & hemicellulose - Gums and pectins

Wheat Flour Proteins

-7-14% protein -Proteins include: -Albumins and globulins -Albumins important for structure ~ 10% -Globulins not important for structure -Enzymes -Small proportion -Lipase and Lipoxidase -Beta-amylase -Glutenin and Gliadin (85% of protein) -Structural proteins for baking

Chemical Leavening

-Acid and base react to produce CO2 -Baking soda and baking powder -Example: quick breads

Glutenin and Gliadin Proteins

-Classes of proteins -Glutenin: fibrous, elastic (link by S—S) -Gliadin: elliptical, sticky, fluid -Glutenin and Gliadin form a gluten network when mixed with water -Need 2x water by weight to completely hydrate -Kneading causes formation of disulfide and hydrogen bonds resulting in protein matrix = gluten -Provides structure for baked goods -Tenderness and texture

Wheat Flour Starch

-up to 80% starch: 75% amylopectin, 25% amylose -Starch granules are embedded in endosperm -Granules take up water --> gelatinization - Provides structure and volume -Flexible, stretches with gluten strands § - Beta-amylase is present in flour -Breaks down starch to maltose -Most active at 50C/122F

YEAST BREAD PREPARATION

1. Hydrate yeast 2. Mixing 3. Kneading 4. Fermentation (first rise) 5. Punch down and shape 6. Second rise 7. Baking 8. Staling - Retrogradation

FERMENTATION

1. Produce alcohol 2. Preserve food 3. Make foods more digestible - eliminate "anti-nutrients" 4. Decrease toxicity of foods 5. Increase flavor, aromas, and textures 6. Add nutrients: essential amino acids, vitamins, protein 7. Reduce cooking time

FACTORS AFFECTING STARCH FUNCTIONALIT

1. Ratio of amylose to amylopectin 2. Size of granule 3. Length of amylose chains 4. Impurities

NATIVE STARCHES (NATURAL FORM

1. Stringiness, cloudiness 2. Overly viscous textures 3. Gelling when not desired 4. Swollen, broken granules leadsto loss of viscosity, gummytexture 5. Retrogradation and syneresis

STARCH CHARACTERISTICS & QUALITY

1. Thickening power 2. Translucency 3. Texture 4. Flavor release 5. Stability 6. Storage 7. Hydration vs. none

BIOLOGICAL LEAVENING: YEAST

Achieved by fermentation of sugars by yeast Single-celled microorganism Multiplies rapidly with correct temperature, sugar, salt, and moisture Baker's Yeast: Saccharomyces cerevisiae

Physical Leavening: Air

Air bubbles are formed during mixing. -Egg foam Fat type: butter helps to trap air (creaming) -compare to oil Air expands with heating

GLUTEN-FREE FLOUR

Almond flour¡ Buckwheat flour¡ Sorghum flour¡ Arrowroot flour¡ White or brown rice flour¡ Oat flour¡ Corn flour Chickpea flour¡ Coconut flour¡ Tapioca flour¡ Cassava flour¡ 1:1 GF baking flour

STARCH

Amylose: 1,4-∝ linkage -linear Amylopectin: 1,4-∝ and 1,6-∝ linkage - branched -soluble

1. RATIO OF AMYLOSE TO AMYLOPECTI

Amylose: tangles up around water andamylopectin¡ More amylose = firmer gelation¡ Longer chains = better for thickening Amylopectin: quickly absorbs water¡ Influences faster gelatinization &thickening All natural starches contain both

QUICK BREADS

Are not leavened by microorganisms but rather by physical or chemical means Examples: muffins, biscuits, popovers, cream puffs, waffles, pancakes, cake doughnuts Differ in ingredients and their ratios, methods of mixing, baking method -Ingredients: flour, liquid, salt -Ratio of liquid: flour varies -Liquid usually milk (also juice, water, zucchini) -Type of fat: oil, butter (solid or melted), shortening, margarine

YEAST IN SOURDOUGH BREAD

Bread made with wild yeast (S. exigus & S. inusitatus) Symbiotic bacterial culture (Lactobacillus sanfranciscenis) -Produces lactic acid: reduces pH to optimal level for yeast fermentation (pH ≤ 4.5

BAKING APPLICATIONS: CLASSIFICATION

Breads (Yeast, Quick)¡ Cakes (Foam, Shortened) Pastry (Plain, Puff) Cookies

INGREDIENTS: EGGS

Contributes to liquid amount - moisture Yolk: emulsifying agent, fat, color, and flavor -Fat + emulsifier= increased tenderness Coagulation of egg white proteins contribute to structure, support volume increase

Batter vs. Dough

Defined by the ratio of flour to water -Dough= more flour, can be manipulated by hand -Batter= more water, pourable

PURCHASING YEAST: Compressed yeast

Disperse in lukewarm water (32-38oC/89-100oF) Alive and perishable, up to 5 weeks in fridge

IMPURITIES IN STARCH

Examples: bran, dirt, protein, sediment -Provide stability to granules takes more energy to gelatinize -Appear cloudy: not translucent -Too many impurities interfere with amylose gel formation -Can also include other things in the starch like protein and fat

INGREDIENTS: FAT

Flavor Creamy color from yellow fats Texture: retards gluten development, increases tenderness -Coats surface of gluten proteins, resulting in reduced hydration of flour proteins

INGREDIENTS: SALT

Flavor Strengthens gluten network Slows fermentation rate of yeast (The Goldilocks Principle) -Salt free --> fermentation occurs too quickly, less gluten strength -Gluten not strong enough to capture gas bubbles -Too much salt added --> fermentation and CO2 production reduced/slowed -Optimum level (1.5-2% of flour weight) à rate just right to support leavening Enhances activity of amylases --> converts starch to sugars for yeast Reduces breakdown of flour proteins by proteases --> protects gluten strength

YEAST BREAD INGREDIENTS

Flour: structure (gluten proteins, starch) Yeast: leavening (fermentation) Liquid: hydrate gluten Salt: flavor, fermentation rate Sugar: sweetness, fermentation, browning

INGREDIENTS: LIQUID

Hydrates glutenin and gliadin allowing formation of gluten matrix Milk provides water, fat, protein, and lactose Scalding milk: heat to at least 92oC/198oF for one minute (or hold at lower temperature) -Must cool before adding yeast -Denatures proteins (whey may interfere with yeast fermentation, gluten development) -Before pasteurization: destroy bacteria

INGREDIENTS: EMULSIFIERS

Functions: to disperse fat on gluten strands and starch granules -Disperse fat = more tender bread -Delay gluten formation Lecithin, mono- and diacylglycerides Egg yolk lecithin

GELATINIZATION VS. GELATION

Gelatinization -unique to starches -Heat breaks hydrogen bonds in starch granules --> water enters granule --> water continues to enter causing granule to swell --> ↑ water in granule, ↓ free water surrounding granule -Some amylose leaves the granule for water surrounding it¡ -Water forms hydrogen bonds with amylopectin and amylose Gelation -All liquid within solid structure

GELATINIZATION VS. GELATION

Gelatinization - swelling of starch granules when starch is heated in water - influenced by amylopectin Gelation - formation of a gel: liquid dispersed in a solid (or a sol à gel when cooled) -influenced by amylose

PURCHASING YEAST: Active dry yeast

Granular, dehydrated, dormant Rehydrate at higher temperature (40-46oC/104-115oF Storage at room temp (6 months) or in freezer (2 years)

FIBER

INDIGESTIBLE POLYSACCHARIDE

AMYLOSE CHAIN LENGTH

Impacts degree of gelation as mixture cools -Amylose outside of granule in free water -↓ temperature = ↓ in energy -Amylose molecules form hydrogen bonds with each other in lower energy state -Bonded amylose create solid matrix-becomes continuous phase -Remaining free water and swollen starch granules are dispersed phase -More amylose correlated with longer chain length and stronger gels Low amylose starches (20% or less) DO NOT form gels

SIZE OF GRANULE

Largest = better water absorbing capacity --> better gelatinization -Potato: largest granule size à superior thickening ability -Roots tend to be better than cereal starches (potato,tapioca, arrowroot -Increased viscosity Cereal starches: smaller granules --> inferior thickening ability -Cereals are less effective compared to roots (corn, wheat,sorghum, rice) -Wheat is the least effective: flour is least effective due to-impurities -More soluble but less viscous solutio

QUICK BREADS: MUFFINS

Leavening: CO2 from baking powder and steam Structure: - rapid development & coagulation of gluten and egg proteins -Mixed by muffin method -Sticky batter - 2:1 ratio of flour to liquid Flavor, color: fat, egg yolk, Maillard reaction

QUICK BREADS: BISCUITS

Leavening: CO2 from baking soda + buttermilk, some steam if butter used Structure: -flakiness from layers of melted fat in between dough -slow development & coagulation of gluten (stir and knead) -Biscuit method -Usually 3:1 flour to liquid ratio Flavor, color: - buttermilk → white interior - baking soda → creamy/yellow color, - fat - Maillard reactions

FOAM C AKES: ANGEL FOOD CAKE

Leavening: air (egg white foam) and steam Structure: - Coagulated proteins in egg white foam - Foam stabilized by sugar and cream of tartar - Soft peaks --> larger final cake - Cake flour: less gluten, more tender - Cool inverted Color: white (bleached anthoxanthins in flour), no yolks, Maillard reaction Egg white foam

FOAM CAKE: CHIFFON

Leavening: baking powder & expanding air from egg white foam, steam from liquid Structure: - Tender, egg white foam - Coagulated egg proteins - Stabilized by sugar - Fat disrupts gluten network (tender) Flavor & color: yellow from egg yolk, sugar, fat, Maillard reaction Fat and egg white foam Hybrid between foam and shortened

FOAM CAKE: SPONGE

Leavening: expanding air from egg white foam and egg yolk foam, steam Structure: - Tender - Egg white foam (soft peaks) - Egg yolk foam (viscous) - Coagulated egg proteins - Stabilized by sugar Flavor & color: yellow from egg yolk, sugar, Maillard reaction Egg white and egg yolk foams

QUICK BREADS: POPOVERS

Leavening: steam from the liquid in the batter (hollow interior) -1:1 ratio of flour: liquid Structure: -large central cavity -coagulation of egg protein -gelatinization of starch -NO gluten formation (proteins too diluted) Flavor, Color: egg yolk, Maillard reaction

Wheat Flour Production

Milling: grinding and refining of cereal grains -removes germ and bran layers --> refined flour -prevent rancidity (spoiling of fats) Bleaching: remove yellowish color in freshly milled flour (xanthophylls) -benzoyl peroxide used industrially Aging: changes that occur to flour during storage -protein -SH groups become linked by disulfide bonds S-S (promotes elasticity) -Accelerated using chlorine, acetone peroxide, or azodicarbonamide Enrichment -Supplemented with thiamine, riboflavin, niacin, folic acid, and iron

WHEAT FLOUR

Natural form contains bran, germ, and endosperm, Natural form appears brown and speckled White flour removes bran and germ Natural white flour still appears light brown White flours may be bleaching products like chlorine dioxide and benzoyl peroxide to appear more white

YEAST BREADS: BAKING

Oven spring: > 80% increase in volume caused by expansion of CO2 Temperature -Too high: crusts before there's enough time for max expansion -Too low: too much expansion, gluten strands break At 60oC/140oF -Yeast killed -Amylase inactivated -Starch gelatinizes Crust browning: Maillard reaction -Promoted by evaporation of water --> increases surface temp -Milk enhances

Types of Leavening

Physical -Air -Steam Chemical -Acid/Base reaction Biological -Yeast

YEAST BREADS: GLUTEN DEVELOPMENT

Provides structure Mixing -Distribute ingredients - Hydrate glutenin and gliadin -Generate glutenin concatenations (S-S linked) -Glutenin concatenations brought into contact with gliadin Kneading: gluten developed through applying mechanical energy -Stretch, fold, and compressed repeatedly -Starch embedded in matrix -Rough --> smooth,stretchy,manipulatable,elastic

Leavening Agents in Baking

Purpose: create gas bubbles to increase volume, change texture, and create crumb. Crumb= network of starch and protein filled with tiny air bubbles Crust= outer dense surface

PURCHASING YEAST: Quick-rise active dry yeast

Rapid CO2 production More readily takes up water Does not need to be rehydrated

COOKIES

Ratios and types of ingredients vary widely Leavening: baking powder or baking soda + acid, creaming solid fat Structure: - high proportion of sugar and fat - Small amount of liquid -limited starch gelatinization -Less steam, denser, less cakey - Egg protein coagulation - Eggs emulsify fat Texture: dense, crumbly Flavor & color: golden from butter, yellow from egg yolk, darker from brown sugar, Maillard reaction

Alternative Flours

Rye flour: most similar to wheat -Has glutenin and gliadin but not as effective in baked goods -Less gluten= dense bread Triticale flour: cross of wheat and rye - strains more similar to wheat are better for baking Gluten free flours: -Generally a mixture of grains and gums -Rice flour, Corn flour, Potato Flour, Quinoa flour, Soy flour, Tapioca Flour -Xanthan gum, agar, cellulose

OTHER TYPES OF FLOURS

Self-rising flour: -Lower protein content (8.5%) -Contains baking powder and salt¡ Italian-style, Doppio, or 00 flour -Lower protein content (8.5%) -Very fine texture often used when light and airy texture is the goal

YEAST BREADS: STALING

Staling begins immediately: -Retrogradation: crystallization of amylose -Heating reverses -Loss of moisture and water relocation -Water used to gelatinized starch during heating returns to gluten -Texture changes: firm, crumbly, flavor decreases Refrigeration increases firmness but prevents mold growth. Freezing inhibits firming of crumb.

Wheat Flour Composition

Starch; 70-80% water: 12-14% protein: 7-14% fat: 1-2%

Baking Soda and Acid

Step 1: Baking soda and acid ionize -Forms salt and carbonic acid Step 2: Carbonic acid dissociates -Forms water and CO2

Chemical Leavening: Double Acting Baking Powder

Step 1: Mixing at Room Temperature - Readily soluble in cold H2O = rapid - Liberates 70% of CO2 in 2 minutes Step 2: Sodium Aluminum Sulfate (SAS) - Reacts readily with hot water forming sulfuric acid Step 3: Sulfuric acid reacts with unneutralized sodium bicarbonate from previous reaction to form CO2

glycogen

Storage form of glucose in animals

PASTRY: PIE CRUST

Structure: fat restricts gluten development -2: 1 flour to fat ratio by volume Texture: tender, flaky due to high fat content -Oil: mealy dough, less flaky, more tender -the smaller fat is cut, more tender -more water, more gluten development, less tender Leavening: steam if butter used Flavor & color: fat -sources: butter, shortening, lard, oil

PASTRY: PUFF

Structure: gluten hydration & development Texture: flaky Leavening: fat melts, steam from butter and water force layers apart Flavor & color: golden from butter Uses butterCareful manipulation to generate layers

Types of Wheat Flour

cake: 7.5% pastry: 7.9% all purpose: 10.5% bread: 11.8% durum: 13% gluten: high protein

INGREDIENTS: SUGAR

Sweetness Energy source for yeast -Increases volume (optimal 3-6% of flour weight) Retards gluten development, increases tenderness -Hygroscopic: competes for water, reduced hydration of gluten proteins Too much delays fermentation by removing water from yeast Enhances browning (Maillard reaction)

SHORTENED CAKES

Tender from fat disrupting gluten development Leavening: baking powder, steam from liquid, sometimes egg foam Structure: - Many variations - May use sugar/fat foam - Coagulated egg proteins (may or may not use foams) - Gluten - Gelatinized starch - Sugar delays gluten formation and egg coagulation Flavor & color: yellow from egg yolk, Maillard reaction Shortened= fat (oil, butter) tenderizes

MODIFIED STARCHES

Thin-boiling starches - debranched amylopectin = thin sol¡ Oxidized starches - debranched amylopectin + alkaline = soft gel Starch phosphates - thickener with excellent stability and clarity

Common Ingredients in Baked Goods 3 basic components

Three basic components: 1. Water 2. Wheatflour:gluten proteins 3. Wheatflour:starch Other common ingredients: - Leavening agent - Liquids - Eggs - Fats - Sugar - Salt

QUESTION 1: MAKING YEAST BREAD

What would happen to your yeast bread in the following conditions? You use rapid rise yeast (instant) instead of active dry You ferment the dough above 35oC You add excess sugar You add oil to your dough You add eggs to your dough

Types of Wheat Flour

Whole wheat vs. White Flour -Whole wheat = bran, germ, endosperm -White= endosperm -Protein is higher in whole wheat (13% vs. 10%) -Fat is higher in whole wheat -Other nutrients high in whole wheat: -Fiber, B vitamins, Fats

YEAST ACTION: FERMENTATION

Yeast is a living organism Metabolizes sugars to produce ethyl alcohol and carbon dioxide Glucose preferred substrate -Sucrose, fructose, and invert sugars about same rate -Maltose and lactose less well Enzymes in flour and yeast catalyze break down of larger sugars to fermentable ones. -Sucrase in yeast (inversion of sucrose), a, B amylases in flour (starch)

Potassium acid tartrate =

cream of tartar

COMPLEX CARBOHYDRATES complex carbs:

oligosaccharides and polysaccharides

cellulose & hemicellulose:

plant cell wall structure

Gums and pectins:

polymers of monosaccharides that are NOT glucose

starch

storage form of glucose in plants

OTHER FACTORS THAT INFLUENCE GELATINIZATION & GELATIO

temp; Need to heat high enough for gelatinization & gelation but nottoo long or can impact: 1. Gelatinization - granules can implode = small fragments = decreased viscosity 2.Gelation - extended heating can break amylose starch chains into small fragments resulting in pasty texture (lumpy gravy) and weak ge agitation: reduce during gelation process (cooling) - agitation interferes withamylose matrix formation and gel strength sugar; -hygroscopic - competes with starch for water, increases temperature ofliquid and increases cooking times for gelatinization§ - results in more tender gel and greater translucency acid; can shorten amylose chains resulting in more tender gel egg; must be cooked to denature ∝ −amylase: amylose-digesting enzymein yolk