Transcript Thinking out of…and inside…the box!

Food Science B
Cookies!
Science Olympiad
Food Science B Event 2010
Sharon Ramsey
Department of Food, Bioprocessing and
Nutrition Sciences
NC State University
Notebooks

Notebook keeping
experiments 30% of score
 label, nutrition calculations, paragraph 22% of
score

SO Coaches Institute 2009
Notebooks




Any notebook that securely holds all items
Number all pages
Table of contents –
Document each trial. Data!



Discuss results, changes. Graphs need labels.
Include Package Labels in notebook– no package this
year-, Nutrition calculations and explanatory paragraph
for cookies
Will be returned as you leave event
SO Coaches Institute 2009
Spoilage/contamination


Good sanitation in “lab”
area
During processing




Metal contamination
Ingredient contamination
Heating, cooling problems
Storage



Molds
Flavor changes
Texture changes
SO Coaches Institute 2009
Before your event

experiments and label
Methods for forming
 Differences in lipids, sugars, time and
temperature effects

Traditional, convection, microwave ovens
 Maillard browning, caramelization


Labeling
SO Coaches Institute 2009
Types of heating

Types of heating
Convection – moving air
 Conduction – contact
 Radiation - broiler
 Microwave – energy into water, fat and sugar
molecules

SO Coaches Institute 2009
Moisture loss in cookies




Need to weigh dough before
and cookie after cooling.
Subtract weight of cookie
from weight of dough to find
amount of water lost
Divide water lost by initial
weight of dough and
multiply result by 100
(Weight initial-weight final) x 100
weight initial
SO Coaches Institute 2009
Density

Mass per unit volume




Expressed in kilograms per cubic meter (kg/m3) or
grams per cubic centimeter (g/cm3)
dependent on temperature and pressure (PV=nRT)
Liquids- Place a known volume of liquid on a balance
measure in graduated cylinder, pipet, etc.
Solids
 traditional shapes
 may use geometry to figure out area of sample,
then weigh to obtain mass
SO Coaches Institute 2009
Labeling





Name for product…get creative!
Ingredients, nutritional label (correct from
ingredients) and serving size
Weight of package (for one batch of
cookies)
Graphics – take photo or draw pictures
Marketing message
SO Coaches Institute 2009
Labeling


Size of print
Placement of label items
main item name is largest type on package
 ingredients statement- ingredients in
decreasing order
 company name and address
 Weight for package


http://www.netrition.com/rdi_page.html
SO Coaches Institute 2009
Nutritional labels






Carbohydrates and proteins yield 4 kcal/g when
consumed
lipids average yield 9 kcal/g when consumed
fats are the most concentrated source of food calories
carbohydrates are the cheapest source of calories
proteins the most expensive
Labels should be complete. Must figure out values by
using the values of ingredients and amount used. These
are mostly math problems.
SO Coaches Institute 2009
Nutritional labeling
If your final formulation contains 1 cup flour, 1 cup
butter, 1 cup sugar and 1 tsp vanilla, how would you
calculate the nutrition facts and ingredient list?
1. Use nutrition facts from each ingredient.
2. Make a table in your notebook for each type of
nutrient (total fats, saturated fat, cholesterol, etc.)
3. Calculate the number of servings of each ingredient
in your formulation (total grams used/g in serving
size).
4. Multiply each type of nutrient by this number and
place answer in table.
5. When all ingredients done, total results for batch.
6. Divide these results by the number of cookies the
batch of dough made.
7. Figure out serving size you want or use labeling
regulations (2-3 cookies, 10 cookies? Depends on size
– marketing?).
8. Multiply the results of step 6 times the number of
cookies in the serving.
SO Coaches Institute 2009
At the event

Basic lab skills for event

Pipeting


Measuring and weighing



To Tare or not to Tare?
Accuracy counts!
Calculations and results


What is a drop?
Significant figures
Procedures will be
given…will not need to
memorize them step by
step
SO Coaches Institute 2009
Day of Event


Notebook (containing
label) and cookies
checked in by 9:00 am
Afternoon events similar
to events in prior years
but all questions based
on cookies.
SO Coaches Institute 2009
Cookie judging




At least 5 representative cookies must be
brought for judging. Plated, bagged OK.
Must be covered and sanitary.
Judged on appearance, flavor, texture and
creativity
Judges will each taste cookies in event.
They have right to disqualify cookie (not
eat) if it doesn’t look sanitary.
8% of event score
SO Coaches Institute 2009
Questions?

Website for coaches and teams:


www.ncstatefoodscience.info
E-mail specific questions

[email protected]
SO Coaches Institute 2009
Let’s calculate!
SO Coaches Institute 2009
Carbohydrates

Carbohydrates



Cx(H2O)y carbon along with
hydrogen and oxygen in the
same ratio as water
Basic unit – monosaccharide
Multiple units –




disaccharide (2)
trisaccharide (3)
oligosaccharide (2-10)
polysaccharide (>10)
SO Coaches Institute 2009
Carbohydrates

Sugars

Monosaccharides


Disaccharides



SO Coaches Institute 2009
Glucose, Fructose
Lactose (glucose and
galactose) -milk
Maltose (glucose and
glucose) Sucrose (glucose and
fructose –table sugar)
Carbohydrates
Polysaccharides
 Examples:




starch - glucose polymers, found in plants
cellulose –found in plant fibers, insoluble
Pectin-units are sugar acids rather than simple
sugars, found in vegetables and fruits
Branched vs. linear

Starches are a mixture of branched (amylopectin) and
linear (amylose) polysaccharides
SO Coaches Institute 2009
Carbohydrates

Reducing sugars


Examples: glucose, lactose, fructose
Non-reducing sugar contains no
hemiacetal groups.

Example: sucrose
SO Coaches Institute 2009
Tests for carbohydrates


Benedicts test for
sugars
Iodine test for starch
SO Coaches Institute 2009
Positive
reaction
Benedict’s Test




The 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 redbrown 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
SO Coaches Institute 2009
Iodine Test



The 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.
Retrieved from
"http://en.wikipedia.org/wiki/Iodine_test"
SO Coaches Institute 2009
Lipids



Present as fats extracted from plants or
animals (butter, vegetable oil) or as
constituents of food (chocolate)
Contributions to foods: texture and flavor
Contain only Carbon, hydrogen and
oxygen
SO Coaches Institute 2009
Lipids



Most common form for lipid in foods is as a
triglyceride
What difference in texture would you see
substituting vegetable shortening or vegetable
oil for butter in the formulation?
http://www.wellsphere.com/healthy-cooking-article/butter-vs-shortening-inbaking/156136
SO Coaches Institute 2009
Lipids

Brown Bag Test
SO Coaches Institute 2009
Lipids


Conversion between solid structure to a
liquid state is called the melting point
How would changing the melting point of
the lipid used change the cookie texture?
SO Coaches Institute 2009
Proteins

Proteins are made up of amino acids

essential and nonessential

Contains Nitrogen
Protein can be found in the flour, egg and
milk as well as other ingredients.
SO Coaches Institute 2009
Proteins


Biuret Test
The 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.
SO Coaches Institute 2009
Density

Measure of mass per unit volume



Expressed in kilograms per cubic meter
(kg/m3), grams per cubic centimeter (g/cm3)
dependent on temperature and pressure
(PV=nRT)
Solids

may use geometry to figure out volume of sample,
then weigh to find mass.
SO Coaches Institute 2009
Leavening agents





Used 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
SO Coaches Institute 2009
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
react
used to neutralize acids in foods
around 4 times as strong as baking powder
can cause soapy flavor in high amounts
SO Coaches Institute 2009
Leavening agents

Baking powder





NaHCO3 plus acidifier(s) and drying agent (usually an acid
salt and cornstarch)
can cause acidity and/or bitter off-flavor
two acidifiers used in double acting to produce CO2 in two
steps
Reacts when moistened and also reacts when heated
double-acting is the only commercial baking powder
available today.
SO Coaches Institute 2009
Where to start?

http://www.ncstatefoodscience.info
Former state and regional event
questions that are applicable to the
new event
 Sources for reagents and supplies
 Information and instructions specific
to the tasks and competition

SO Coaches Institute 2009
Time to play!

Leavening agents
SO Coaches Institute 2009