2 DisclaimerThis presentation was prepared using draft rules. There may be some changes in the final copy of the rules. The rules which will be in your Coaches Manual and Student Manuals will be the official rules
3 Safety Students must wear: Closed shoes Slacks or skirts that come to the anklesLab coat or lab apronIndirect vent or unvented chemical splash proof goggles. No impact glasses or visorgogs are permittedLong-Sleeved Shirt (if wearing a lab apron)
4 What Students MUST Bring ImpoundedNoneNon-ImpoundedHomemade viscometerStandard curveA writing instrument
5 What Students May Bring Non-programmable Calculator1 sheet of paper on which anything is acceptable
6 What Supervisors Will Supply Everything the student will needThis may include:GlasswareReagentsBalancesHot platesThermometersProbesMagnetsStirrers
7 Main Focus Chemistry of Food How to prepare students Experiment ideas Resources
8 Chemistry of Fooda. Identify the sources of and understand the role of lipids, carbohydrates and proteins typically found in cookies, and use tests to identify these compounds, including the Benedict’s, Iodine and Brown Bag tests.b. When given samples of sweeteners, use the Benedict’s test to identify reducing sugars.c. When given samples of cupcake ingredients, use the Biuret test to identify and rank the ingredients by protein content.d. When given formulations, processes, and finished cupcakes, identify the error in the cupcake formulation and/or process used.e. Use standard labeling regulations to produce a label from information given.f. Determine the moisture loss and density of cupcakes.g. Identify leavening agents using chemical tests, and understand the role of the leavening agents in baked cupcakes.
9 Before your event Research! Understand the science first Experiments – eight mandatory (includingViscotester Production and Standard Curve)
10 Ingredients The right ingredients Liquids….LipidsLeavening agentsFloursSweetenersMust understand WHY you are using the ingredient…what function does it provide?Teams are limited to listed ingredients
11 List of Approved Ingredients LiquidsLipidsLeavening agentsFloursSweetenersWater, WholeMilk (Cow or Goat), Skim Milk, Buttermilk, Almond Milk, Soy Milk,Coconut Milk, Eggs, Egg SubstituteVegetable oils,Shortening, Butter Margarines,ChocolateBaking powderBaking sodaCream of tartarFlavoringSaltAll purpose white flourBread flourCake flourWhole wheat flourAlmond flourCoconut flourCorn FlourRice FlourSugarBrown sugar Honey Sucralose AspartameVanillaFor State & NationalsFructosePowdered SugarEach recipe must contain at least one egg or one egg substitute equivalent.
12 Carbohydrates Carbohydrates Basic unit – monosaccharide Cox(H2O)y carbon along with hydrogen and oxygen in the same ratio as waterBasic unit – monosaccharideMultiple units –disaccharide (2)trisaccharide (3)oligosaccharide (2-10)polysaccharide (>10)
13 Carbohydrates Sugars Reducing sugars Monosaccharides Examples: glucose, lactose, fructoseNon-reducing sugar contains no hemiacetal groups.Example: sucroseSugarsMonosaccharidesGlucose, FructoseDisaccharidesLactose (glucose and galactose) -milkMaltose (glucose and glucose) -Sucrose (glucose and fructose –table sugar
14 Carbohydrates Polysaccharides Examples: Branched vs. linear starch - glucose polymers, found in plantscellulose –found in plant fibers, insolublePectin-units are sugar acids rather than simple sugars, found in vegetables and fruitsBranched vs. linearStarches are a mixture of branched (amylopectin) and linear (amylose) polysaccharides
15 Tests for carbohydrates Benedicts test for sugarsIodine test for starchPositive Reaction
16 Benedict’s TestThe Benedict's test allows us to detect the presence of reducing sugars (sugars with a free aldehyde or ketone group). All monosaccharides are reducing sugars. Some disaccharides are also reducing sugars. Other disaccharides such as sucrose are non-reducing sugars and will not react with Benedict's solution. Starches are also non-reducing sugars. The copper sulfate (CuSO4) present in Benedict's solution reacts with electrons from the reducing sugar to form cuprous oxide (Cu2O), a red-brown precipitate.The final color of the solution depends on how much of this precipitate was formed, and therefore the color gives an indication of how much reducing sugar was present if a quantitative reagent was used.With increasing amounts of reducing sugar the result will be:green yellow orange red
17 Iodine TestThe Iodine test is used to test for the presence of starch.Iodine solution – Iodine is dissolved in an aqueous solution of potassium iodide - reacts with starch producing a deep blue-black color.Although the exact chemistry of the color change is not known, it is believed that the iodine changes the shape of the starch to change the color
18 LipidsPresent as fats extracted from plants or animals (butter, vegetable oil) or as constituents of food (chocolate)Contributions to foods: texture and flavorContain only Carbon, hydrogen and oxygenMost common form for lipid in foods is as a triglycerideWhat difference in texture would you see substituting vegetable shortening or vegetable oil for butter in the formulation?
19 Saturated Lipids (Fats) Saturated fats have no double bonds in any of the fatty acid chains in the triglyceride hence it is saturated with hydrogen.Considered not heart healthyFoodLauric acidMyristc acidPalmitc acidStearic acidCoconut oil47%18%9%3%Butter11%29%13%Dark chocolate0%34%43%Eggs0.3%27%10%Soybean oil4%
20 Unsaturated Fats (Lipids) Have one (monounsaturated) or more (polyunsaturated) carbon chainsThis means there are one or more double bonds in the chain
21 LipidsConversion between solid structure to a liquid state is called the melting pointHow would changing the melting point of the lipid used change the cookie texture?Brown Bag Test
22 Proteins Proteins are made up of amino acids essential and nonessentialContains NitrogenProtein can be found in the flour, egg and milk as well as other ingredients.
23 ProteinsBiuret TestThe Biuret Reagent is made of sodium hydroxide and copper sulfate. The blue reagent turns violet in the presence of proteins, and the darker the purple color, the more protein is present.Biuret’s Reagent is unstable, but can be mixed on the spot using NaOH & Benedicts
24 Leavening agentsUsed to produce a gas that 'lightens' dough or batter.used to raise baked goods.water a leavening agent (pie crusts, some crackers)air incorporated into batter (angel and sponge cakes)expand when heated and cause the raising of the dough or batter when gas is trapped in matrix of gluten and starch from flour
25 Leavening agents Baking soda -NaHCO3 Needs moisture plus an acid source such as vinegar, citrus juice, sour cream, yogurt, buttermilk, chocolate, cocoa (not Dutch-processed), honey, molasses (also brown sugar), fruits or maple syrup to reactused to neutralize acids in foodsaround 4 times as strong as baking powdercan cause soapy flavor in high amounts
26 Leavening agents Baking powder NaHCO3 plus acidifier(s) and drying agent (usually an acid salt and cornstarch)can cause acidity and/or bitter off-flavortwo acidifiers used in double acting to produce CO2 in two stepsReacts when moistened and also reacts when heateddouble-acting is the only commercial baking powder available today.
27 Standard Recipe• 2 1/4 cups flour • 1 1/3 cups sugar • 3 teaspoons baking powder • 1/2 teaspoon salt • 1/2 cup shortening • 1 cup milk • 1 teaspoon vanilla • 2 large eggs
28 Effect of Ingredients Batch # Flour Leavening agent Sweetener Liquid EgglipidSaltVanilla12 ¼ cups3 tsps. baking powder1 1/3 Cup1 cup milk or sub.2 large or substitutenone½ tsp.1 tsp.23 Tbsp oil3None43 tsps. baking soda52 cup milk or sub.62 1/3 Cup
29 Mixing Technique Incorporate ingredients Hydrate dry ingredients Experiment set 2 explores the best method to mix the batter
30 Standard MixingPreheat oven to 350 degrees. Line cupcake pans with paper liners.Combine flour, sugar, baking powder, and salt in a large mixing bowl. Add shortening, milk, and vanilla. Beat for 1 minute on medium speed. Scrape side of bowl with a spatula.Add eggs to the mixture. Beat for 1 minute on medium speed. Scrape bowl again. Beat on high speed for 1 minute 30 seconds until well mixed.Spoon cupcake batter into paper liners until 1/2 to 2/3 full.Bake for 20 to 25 minutes or until toothpick inserted in center comes out clean.Cool 5 minutes in pans then remove and place on wire racks to cool completely.
31 Mixing Technique Batch # Step 1 Step 2 Step 3 Step 4 1 Mix dry ingredientstogetherAdd liquidUsing spoon, stiringredients for 30 secondsAdd egg. Use spoon to stir for 1 minute2Mix dry ingredients togetherPour into blender or use hand mixer and blend or mix 2 minutesAdd egg. Use mixer or blender to blend for 1 minute3Use whisk, stiringredients 1 minuteAdd egg. Use whisk, stiringredients 2 minutes
32 Notebook/3-ring binder Notebook keeping (teams are encouraged to bake goods, observe and record the differences caused by adjusting the ingredients from the Approved List of Ingredients). Optional but suggested for keeping records of all experimental data and documentationMay be bound, spiral, or ringMust securely hold all itemsDon’t erase in lab notebook!Document all referencesUse pen
33 Notebook i. Experiment Name – 2 Points ii. Hypothesis – 4 points iii. Variables:a. Controlled Variable(s) – 2 pointsb. Independent Variable(s) – 2 pointsc. Dependent Variable(s) – 2 pointsiv. Materials (amount of each ingredient in grams or milliliters) – 4 pointsv. Procedure – 10 pointsvi. Qualitative observations during the experiment (be sure to include sensory score sheet) – 6 pointsvii. Quantitative observations during the experiment (Data table, graphs-be sure to include nutritional calculations, viscosity testing, density, and crumb testing results) – 10 pointsviii. Discussion of Results – 6 pointsix. References – 2 points
34 CupcakeUse any combination of ingredients from the approved list as well as physical parameter changes (temperature, cupcake lining materials, etc.) to formulate an ideal team cupcake. Teams may choose variables used in the first two experiments or use new variables. If a recipe from a cookbook or web site is used as a starting source, the source must be listed in the notebook.Aiming for a density of 0.3 g/mlAiming for less than 0.3% of the mass of the cupcake to be left on liner or in crumbs when liner taken offMust have nutrition food label
35 Viscotester Made from 8 oz Styrofoam cup Heat 16 penny nail with tea candle for ~1 minute (or until it gets too hot to hold)Punch hole from INSIDE into center bottom of cupPlace tape over holeTime how long it takes for same amount of each standard liquid to break flow as it leavesWhen determining how much fluid to use, keep a couple of items in mindThe larger the amount of fluid the less influence reaction time will have on error.The amount of fluid the event supervisor is likely to allow the team to have.
36 Standard Curve Use same amount of standard fluids to calibrate Time how long it takes to break stream
38 ViscosityStudents need to investigate viscosity of their batters and compare to final results.The resistance of a fluid to deformation.Temperature dependent*Dynamic or simple viscosityKinematic viscosity: ratio of viscosity/densityShear viscosity – reaction to a shearing stress (pumping, spraying, etc.)Must know general nomenclature
40 Less than .19 or greater than .42 Density Score SheetStudents should measure the density of each of their experimental cupcakes and recordSuggested DensitySuggested Score5or4or3or2Less than .19 or greater than .421
41 NutritionStudents will create a food label for their cupcakes properly indicating serving size, calories, amount fat, unsaturated fat, saturated fat, carbohydrates, sugars, fiber, and protein, as well as accompanying daily value percentages.Students are NOT to be scored on how healthy the cupcake is, only on their ability to identify its role in a healthy diet.
42 NutritionCalorie - amount of heat required to raise the temperature of 1 gram of water 1 degree Celsius.Kilocalorie (1000 calories) is the unit commonly used to represent energy values of foods -or Calorie with a C instead of a cNot all carbohydrates (or fats, or proteins) yield the exact same amount of energy when burned in a calorimeter, so common averages from studies (in kcal/g) are usedCarbohydrates average 4.1 kcal/gram in a bomb calorimeter, are about 98% digestible and yield 4 kcal/g when consumedProteins average 5.7 kcal/g in a bomb calorimeter, are not as easily digested and yield an average of 4 kcal/g when consumedLipids average 9.5 kcal/g in a bomb calorimeter, are 95% digested and yield an average of 9 kcal/g when consumedFats (lipids) are the most concentrated source of food caloriesCarbohydrates are the cheapest source of calories, proteins the most expensive
43 Fiber Foods not digested by human digestive system Two types Soluble Fiber-helps regulate blood sugarFound in Oats & Oat Bran, some Fruits & vegysInsoluble Fiber-helps clean out colonFound in whole wheat, some fruit skins and vegys
44 Nutritional labeling Fill in the following blanks. There are ___ Calories/gram of fat.There are ___ Calories/gram of carbohydrateThere are ___Calories/gram of proteinThere are ___Calories/gram of waterUse the nutritional label given for information to answer the following questions:Calculate the Calories in one serving of this product.Calories from FatCalories from ProteinTotal Calories in one servingWhat percent of the carbohydrate Calories come from fiber?If the daily value of iron is 18 mg per day, calculate the amount (in mg) of iron in one bar of this product.
45 Nutrition Scoring The labels will be scored as follows: i. Creative Cupcake name (5 points)ii. Ingredient List in correct order (15 points)iii. Nutritional Facts in correct order (15 points)iv. Package Weight (10 points)v. Company (team) Name and Address in the correct location (5 points)vi. Label Information matches notebook (10 points)
46 Sensory Score Sheet Attribute Score (Circle for each attribute listed) FlavorAroma1Terrible23Average45Very PleasingStarchRaw or burnedUnder or over cookedSlightly under or over cookedPleasingly cookedVery Pleasingly cookedDairy/MilkySpoiledModerate off-flavorSlightly off flavorOKPleasantSweetnessWay too much or too littleModerately too much or too littleSlightly too sweet or too tartAbout rightPerfect sweetnessVanillaWay too much or not enoughSlightly too much or too littleExcellentTextureSurfaceReally roughSomewhat roughModerately roughSlightly smoothSmoothMoistureDryModerately drySomewhat drySomewhat moistMoisture just rightCohesivenessReally gummySomewhat gummySlightly gummyFalls apart easilyJust rightStickinessReally stickyModerately stickySomewhat stickySlightly stickyCircle any of the following if presentSourBitterAstringentGrittyOxidized (paint) flavor
47 Resources For Event Supervisors For Lesson Plans for classroom use For Lesson Plans for classroom use
49 Time to Experiment We can make viscotesters We can simulate a standard curve data collectionWe can find the viscosity of a batterWe can find the density of muffinsWe can work with some tests from a simulated test.It is your option