Quick Breads Lectures HTM*2700

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University of Guelph *

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2700

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Health Science

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Oct 30, 2023

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Quick Breads Live Lecture March 25, 2021 Functions of Sugar in Baked Products 1. Tenderizer (T) Muffins, T. biscuits & Cakes - Competes with flour proteins (gliadin and glutenin) for H2O - Less hydration of gliadin and glutenin - Controls gluten development 2. Creaming of fat and Sugar Together (L) Cakes only - Air clings to sharp edges of sugar - Air is incorporated into fat - Air clings to white, granulated sugar or brown sugar not icing or powdered sugar 3. Decreases Loss of CO2 from Butter (L) Muffins and Cakes - Sugar dissolves faster than baking soda and baking powder 4. Allows Batter or Dough to Reach Maximum Volume (L) Muffins, Tea biscuits & cakes - Sugar forms hydrogen bonds with i. Starch granules in flour ,  Increases gelatinization temperature  Delays gelatinization ii. Proteins (Gluten, egg, whey)  Increases coagulation temperatures  Delays coagulation Therefore, more time for CO2 and steam to expand air cells (in muffins & cakes) or air pockets (in tea biscuits) = maximum volume 5. Caramelization of Sucrose (C) muffins, tea biscuits, cakes - Non-enzymatic browning reaction - Occurs in dry heat conditions (top and sides of product) - Sucrose (white sugar) hydrolyzes into fructose & glucose which go through a series of reactions creating brown pigments Alternative Sweeteners - Aspartame o Sold under brand names NutraSweet and equal o Dipeptide composed of 2 amino acids: aspartic acid and phenylalanine o 160 – 200 times sweeter than sucrose o Cannot be consumed by those with phenylketonuria (PKU) o Approved by Heath & Welfare Canada in 1981 - Sucralose o Sold under brand name Splenda o Synthesized from sucrose o 3 chlorine (Cl) atoms substituted for 3 of the hydroxyl (OH) groups on sucrose

o 600 times sweeter than sucrose o Looks and tastes like sugar o Behaves like sugar in baked products o Not broken down by heat o Not broken down in body = no calories o ADI = 15 mg/kg body weight/day o Approved by Health & Welfare Canada in September 1991 - Stevia o Leaves of plants which are native to south & central America and Mexico that are 30-45 times sweeter than sucrose o Extract of one component from the stevia leaves is sold under brand names Truvia and PureVia o May have a bitter or licorice-like aftertaste o No calories, no carbohydrates Function of Fat Unsaturated fat - e.g.) canola oil, olive oil, corn oil, safflower & peanut oil - 1 or more double bonds - From plant sources - Liquid at room temperature Saturated fat - All single bonds - From animal sources - Solid at room temperature o E.g. butter, lard (pork fat) Types of Fat 1. Butter - Water-in-fat emulsion (H2O is dispersed phase) - 80% fat, 20% H2O - Animal sources (made from cream) - Saturated fat 2. Margarine - Water-in-fat emulsion (H2O is dispersed phase) - 80% fat, 20% H2O - Made from hydrogenated vegetable oils 3. Shortening

- 100% fat - Partially hydrogenated vegetable oil - Mixture of solid and liquid fat -  easier to manipulate 4. Vegetable Oils - 100% fat - Liquid fats (does not form steam) - Made from corn, canola, sunflower, olives, peanuts etc. Functions of Fat and oils in Baked Products 1. Tenderizer (applies to all baked products) - Coat flour particles - Reduces hydration of gliadin & glutenin proteins o Controls gluten development which increases TENDERNESS - Liquid fat (vegetable oils) have greater ability to coat flour particles than solid fats 2. Flake Formation (tea biscuits, pastry) - Tea biscuits & pastry should have many layers called flakes - Formation of flakes is a multi-stage process - Some steps occur during mixing and remainder during baking - 7 steps necessary for the flakes to form 3. Air incorporation (cakes only) - Occurs during creaming of fat - Creaming = manipulating shortening, butter or margarine with a wooden spoon or electric beater to incorporate air cells - Easier to cream shortening because it is a mixture of solid and liquid fat - During baking fat melts, releasing air cells - Steam & CO2 expands air cells o = cake volume increases/cake rises - Creaming of fat is most important step in achieving high volume cake 4. Emulsification (cakes only) - Cake batter contains large amounts of fat and H2O (mainly milk and egg whites) o Cake batter is fat-in-H2O emulsion o Emulsifier is needed to keep fat (and incorporated air cells) evenly distributed throughout cake batter - 2 sources of emulsifiers: 1. Lecithin in egg yolks 2. Mono and diglycerides in shortening - Emulsifiers have hydrophilic and hydrophobic ends - Ensures fat (and air cells) stayed evenly distributed throughout cake batter - If emulsifiers are NOT present: o Fat floats to top of batter  = cake is light & airy on top, dense and heavy on bottom - Emulsifiers also: increase # if air cells, and decrease size of air cells

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Fat Rancidity = unpleasant odors and flavours which develop in: 1. pure fats (butter, margarine, shortening, vegetable oils etc. 2. foods which contain fat (e.g. meats, nuts, cake mixed. Snack foods, cookies) two types 1. oxidative rancidity – occurs to vegetable oils 2. hydrolytic rancidity – occurs in animal fats such as butter and lard Oxidative Rancidity - occurs in unsaturated fats which have double bonds (e.g. vegetable oils) - higher degree of unsaturation (I.e. more double bonds) =increased susceptibility to oxidative rancidity - complex chain reaction involving oxygen - reaction revolves around the double bonds - catalyzed by: heat, light, iron (Fe) OR copper (Cu) - results in the production of ALDEHYDES and KETONES = unpleasant odours and flavours Prevention of oxidative Rancidity 1. opaque packaging – minimizes exposure to light 2. store oils away from light 3. keep away from heat sources, including oven and refrigerator 4. use a vacuum packaging – eliminates O2 5. add antioxidants: BHA, BHT & propyl gallate – stop chain reaction, citric acid & EDTA – tie up metal ions (Fe and Cu) Hydrolytic Rancidity - occurs in saturated fats (all single bonds) from animal sources - fatty acids split away from the glycerol backbone - some fatty acids have unpleasant odours and flavours - e.g. butter and lard contain BUTYRIC ACID which smells and tastes like rotten eggs - catalyst: heat Prevention of Hydrolytic Rancidity o store fats at cool temperatures  butter is more susceptible to rancidity in summer when left at room temperature

Leaveners (leavening agents) = production or expansion of gases in a batter or dough which gives the final product an increased volume and light porous texture 1. air – incorporated into batters and doughs 2. steam – produced from ingredients containing H2O 3. carbon dioxide – produced from baking powder and baking soda Leavener – Air - incorporated into batters and doughs by: o sifting flou r and other dry ingredients  also ensures accurate measurement  not sifting = too much flour added to recipe o beating eggs o mixing batter s (e.g. muffin and cake batters) - during baking air cells are expanded by carbon dioxide and steam - = increase in volume Air – muffins and cakes - Small air cells incorporated by: o Sifting flour & dry ingredients o Beating eggs o Mixing batter - Air cells expanded by CO2 & steam - = increase in volume (height) Leavener – Steam - Produced from ingredients which contain H2O o E.g. milk, yogurt, fruit, molasses, butter milk, sour cream, fruit juices, egg whites o NOT vegetable oil (100% fat) o NOT dried fruits - Produced during baking when H2O is heated Leavener – Carbon Dioxide = baking soda (sodium bicarbonate) + 2 dry acids - React together to produce CO2 - CO2 is produced in two stages Baking Powder o Baking soda & acids are in perfect balance

o Baking soda & acids in powder react only with each other o Gives a guaranteed amount of CO2 1. Dry acid #1 (monocalcium phosphate monohydrate) + baking soda + moisture during mixing = CO2 produced 2. Dry acid #2 (sodium aluminum sulfate) + remaining baking soda + heat = more CO2 produced Baking soda (sodium bicarbonate) - Alkaline ingredient - Reacts with acid ingredient+ to produce CO2 (no adverse colour or flavour reactions  Acid ingredients – fruit, fruit juices, buttermilk, yogurt, sour cream, molasses etc. - CO2 expands air cells = increased cake volume

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Quick Breads Recorded Lecture March 23, 2021 Quick Breads – Muffins and Cakes Cross section of a wheat grain Endosperm - starch granules - 70-75% protein - 20% of B-vitamins - Aleurone cells Bran - 20% of the protein - > 50% of B vitamins - FIBRE - Scutellum Germ - 8% of the protein - 30% of B vitamins - Saturated fats **don’t need to know this, just for better understanding

Milling of Wheat = conversion of wheat grain into white flours (all-purpose, cake & pastry, bread flour etc.) Involves 2 main processes: 1. Separating the bran and germ from the endosperm 2. Reducing size of the endosperm into flour size particles White flours - Made from endosperm only - Bran and germ are removed from the wheat kernel Whole What flour - Composed of the bran, germ and endosperm ground together into flour - 13% protein - White flours (all purpose and cake & pastry) are enriched with iron and B- vitamins to the levels found in whole what flours Flour Improvers

Freshly milled flour: - Is creamy white colour (xanthophyll) - Gives poor quality baked goods Storing for several weeks (expensive process $$) - Whitens flour - Improves baking quality Add flour improvers: - Azodicarbonamide (ADA) - Potassium bromate - Ascorbic acid (vitamin C) Classifications of What 1. Quality (= protein content) a. Hard wheat  High protein content  Main type grown in Canada  Used for bread-making b. Soft wheat  Lower protein content  Western Europe  Used for muffins, cakes, biscuits 2. Habit (= when planted) a. Winter wheat  Planted in late fall  Harvested mid-summer b. Spring wheat  Planted early spring  Harvested late summer or early fall 3. Colour a. White wheat – pale yellow b. Red wheat – dark red-brown  HARD, RED, SPRING WHEAT is the main type grown in western Canada (mainly Alberta and Saskatchewan) Canadian Wheat 1. Hard, red, spring wheat o 95% of Canadian crop o 14% protein o Manitoba, Saskatchewan & Alberta 2. Hard winter wheat o 12.2 protein

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o Small amount in southern Alberta 3. Soft winter wheat o 9.2 to 10.3% protein o Western Ontario and B.C. Gluten - Complex protein created from proteins found in wheat, rye and wheat flours - Gluten itself is NOT actually present in these flours - 2 proteins gliadin and glutenin are present and they form gluten** - Plasticity – moldability - Elasticity – stretching - Gluten forms when gliadin & gluten in flour are: 1. Hydrated (H2O added) and 2. Manipulated (mixing and kneading) - Gives visco-elastic properties to batters and cough: o Allows them to hold small air cells o Allows a dough to be kneaded and rolled o Allows batters and dough to expands - Gives structure to baked products (e.g., muffins, tea biscuits, cakes) o Complex protein that denatures and coagulates during baking o Excess gluten developed makes baked products tough - Therefore, must control/limit gluten development, but not prevent it *** - Complex protein which develops in a:

1. Batter = uncooked flour mixture that is thick, but can be poured e.g.) muffin or cake batter 2. Dough = uncooked flour mixture that can be shaped e.g.) tea biscuit, pastry or bread dough Structure of baked products (muffins, cakes, tea biscuits, bread, etc.) (p.217) is due to: 1. Starch in flour o Gelatinization during baking (don’t need full definition, need to say occurs during baking because moisten with liquid ingredients) o Retrogradation during cooking 2. Gliadin & glutenin proteins in flour - Hydration + manipulation develops gluten - Gluten denatures and coagulates during baking - Important to have enough gluten for structure but NO excess gluten o Excess gluten = TOUGH product Factors Affecting Gluten Development 1. Type of flour - All purpose o Combination of hard and soft wheat o 10.5% protein (gliadin and glutenin) o Used for all baked products - Cakes & pastry o Made from soft wheat o 9.7% protein o Used for cakes, muffins, pastry (not bread) - Whole wheat o Made from entire wheat kernel (bran, germ and endosperm) o 13.3% protein o Used in all baked products 2. Manipulation (mixing, kneading, rolling) - Increase manipulation = increase gluten development

- Over-mixing of muffin batter o Causes excess gluten development in some areas of muffin batter, which leads to TOUGH texture o During baking, leavening gases have a hard time moving through excess gluten development o Leavening gases collect in areas of least gluten development, causing tunnels to form inside the muffin o Leavening gases push batter up casing a peak to from on top of the muffin 3. Amount of liquid - Excess liquid = increase gluten development in yeast biscuits adding extra liquid: = sticky dough which cannot be kneaded or rolled out = more gluten development = TOUGH texture 4. Tend erizer s = ingredients which control or limit gluten development so excess gluten is NOT produced - Gliadin + glutenin + water + manipulation = GLUTEN a. SUGARS o Competes with gliadin and glutenin proteins for H2O o Reduces hydration of gliadin and glutenin o Controls gluten development  = TENDER product b. FAT (liquid or solid) o Coats flour particles

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o H2O has more difficulty hydrating gliadin and glutenin o Controls gluten development c. BRAN OATMEAL and CORNMEAL o All are very dry and small particles o Bran can be an ingredient by itself or be part of whole wheat flour o Dry particles compete with gliadin and glutenin (protein in flour) for H2O o Reduces hydration of gliadin and glutenin o Controls amount of gluten developed = TENDER o Small particles physically interfere with development of long gluten stands o Shorter strands develop which are more  TENDER Quick Breads 3 rd lecture March 29, 2021 Fat (shortening, butter, margarine) 1. Creaming incorporates air cells (L) 2. Mono & diglycerides in partially hydrogenated fats are emulsifiers - More, smaller air cells, evenly distributed (L) 3. H2O in butter (20%) converted to steam (L) 4. Tenderizer (T) - Coats flour particles - Reduced hydration of gliadin and glutenin - Controls gluten development Leaveners (Leavening agents) *in last lecture Why Use Baking Soda? - Recipe already contains an acid ingredient for flavour o E.g. molasses in bran muffins, yogurt in cornmeal surprise muffins

- Baking soda will react with the acid ingredient to produce more CO2 - Acid ingredients vary in amount of acid they contain, and amount of CO2 produced will vary o Therefore, most recipes with baking soda also contain baking powder Adding Baking Soda without an acid ingredient in the recipe e.g. using baking soda when recipe calls for baking powder = undesirable flavours and colours - Undesirable flavour changes : 1. Sodium carbonate is bitter in flavour 2. Sodium from sodium carbonate reacts with fat (butter, vegetable oil, shortening etc) = soapy flavour - pH of batter or dough increases due to sodium carbonate being produced = alkaline conditions - alkaline conditions = undesirable colour changes: 1. flavonoid pigments in flour intensifies = yellow colour 2. Maillard reaction occurs faster = excess browning on outside surface if you bake for full time OR = product is under-cooked if you remove it from the oven when the outside is browned and looks cooked, but begore the end of the cooking time Colour reactions in Baked Goods 1. Maillard Browning (C) - Btw amino acids and reducing sugars - High heat, low moisture conditions (dry heat) - Won’t see in microwave because trapped in microwave = moist environment (most require dry heat) - Occurs faster in alkaline conditions 2. Caramelization of sucrose (C) - Sucrose (white table sugar) hydrolyzes into glucose & fructose

- Further reacts to from brown pigments - High heat, low moisture conditions (dry heat) - Occurs more readily in cakes due to high sugar content 3. Dextrinization (C) - In dry heat conditions - Starch granules in flour with hydrolyze into dextrins - Dextrins react together to form brown coloured pigments - Non-enzymatic browning Chocolate Cakes - Colour is affected by pH - Slightly alkaline (pH 7.5-8.0) = deep brown (mahogany brown) - Acid pH(pH<7) = yellow brown - Therefore, add small amount of baking soda to increase the pH Functions of Ingredients in Baked Goods - Flour - Liquid ingredients - Eggs Flour o Contains BOTH starch granules & proteins (gliadin & glutenin) o Both contribute to structure (S) of baked product, BUT in different ways o Undergo different rxns (coagulation of gluten, gelatinization & retrogradation of starch) o *see quick bread summary Liquid Ingredients o E.g. milk, egg whites, fruit, molasses, applesauce, yogurt, buttermilk, sour cream 1. Steam production during baking (L) 2. Dissolves baking powder & baking soda  CO2 production (L) 3. Hydrates starch granules in flour + heat  starch gelatinization (S) 4. Hydrates gliadin & glutenin proteins in flour + mixing  gluten development (S) 5. Lactose in milk = reducing sugar  Participates in Maillard browning (C)

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Eggs 1. H2O in egg whites is converted into steam (L) 2. Lecithin in egg yolks ats as emulsifiers (L) o More, smaller air cells evenly distributed 3. H2O in egg whites hydrates: (S) o Starch granules in flour  gelatinization o Gliadin & glutenin in flour  gluten development 4. Proteins in eggs denature during mixing and coagulation during baking (S) 5. Amino Acids in proteins participate in Maillard browning on surface and sides (exterior) of baked product (C) Two Methods of Mixing Cakes - Conventional - Quick mix/one bowl Conventional Mixing of a Cake o Use of electric beater to:  Cream fat (butter, margarine or shortening)  Cream fat and sugar together  Beat in eggs, one at a time o Use a wooden spoon to:  Mix ingredients (flour, baking powder&/or baking soda) alternately with liquid ingredients until well blended o E.g. butter cake Quick Mix Method (of mixing cake) o All mixing done with an electric beater 1. Mix together dry ingredients (flour, sugar, baking powder &/or baking soda) + fat + ¾ milk (2-3 minutes) 2. Add eggs + remainder of milk and beat until batter is well-blended (3 minutes) o Receive more manipulation (electric beater) o Contains extra liquid to make beating with electric beater easier o Therefore, excess gluten can develop o However, quick mix cakes also contain:  More fat & sugar  Limits hydration of gliadin & glutenin  Controls gluten development  Therefore, quick mix cakes are just as tender as conventionally mixed cakes