1. Scientific Evaluation: Being Objective
Chapter 2
Scientific Evaluation: Being Objective

2. Objectives Describe the role of science in new food products.
Identify the function of measuring equipment.
Demonstrate proper measurement techniques.
List steps of the scientific method.
Use safety procedures in the lab.
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3. Science in the Food Industry
Scientific study in any field requires
unbiased observation
accurate measurement
organized documenting of results
To be scientific, an experiment must be replicable, or repeatable
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4. Measurements Successful measuring requires you to
identify what standard is being used (International System of Units)
determine what you want to measure
decide what method of measurement & specify the unit

5. Measuring Mass and Length
Mass measures the quantity of matter
The metric unit is a gram (g)
A kilogram (kg) is the mass of 1 liter of water at 4°C
Weight measures force of gravity between 2 objects
Length is the distance between 2 points
Metric unit for measuring length is meter (m)
Measured with ruler

6. Measuring Volume Equipment used to measure liquids
Volume is amount of space occupied by an object
Metric unit for measuring fluid volume is liter (L)
Equipment used to measure liquids
beaker—a wide mouthed container w/ pouring lip
Erlenmeyer flask—cone-shaped container w/flat bottom
graduated cylinder—tall, thin container w/ pouring lip
buret—a graduated glass tube

7. How to Measure Volume Container on a flat surface
Readings at eye level
In narrow containers read from bottom of curve at liquid’s surface, the meniscus
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8. Measuring Time Measured in seconds Appoint someone as timer
Failure makes experiment invalid

9. Measuring Temperature
A measure of heat intensity
Celsius degree is 0.01 of the difference between the boiling and freezing points of water
Water boils at 100°C
Water freezes at 0°C

10. The Scientific Method A system of steps used to solve problems
Ask questions
Ask what, why, and how of a problem
Define the problem
Clarify question, set goals
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11. The Scientific Method Conduct research
List possible causes of problem
Gather as much info as possible
State hypothesis, or possible solution
A hypothesis repeatedly tested over a variety of conditions becomes a theory
Laws are theories widely accepted
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12. The Scientific Method Design the experiment
Make it answer questions such as how to test the hypothesis, what equipment will be used, how to collect and record the data, and what safety precautions need to be taken
A well-designed experiment will have a variable and a control
Each change in an experiment is a variation
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13. The Scientific Method Conduct the experiment
Follow procedures exactly and measure accurately
Records of observations will be numerical or descriptive
Record data appropriately and neatly
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14. The Scientific Method Evaluate results Report the results Reflect
Look for patterns, common factors, changes, and questions
Look for answers to the questions and whether they provide support for or against the hypothesis
Report the results
A conclusion analyzes and applies data
Experiments may lead to more than one conclusion and reveal need for further research
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15. Evaluating Scientific Studies
A process of discovery and debate
Medical experts may be involved to evaluate
2010 update of the Dietary Guidelines for Americans, recommends consuming more nutrient-dense foods
Conflicting reports may exist
Researchers often examine hundreds of studies before making recommendations
A meta-analysis gives overall conclusions to multiple studies of the same issue
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16. Lab Safety General guidelines Follow lab rules and procedures
Avoid horseplay
Keep hair back
Be cautious around heated glass
Protect eyes and skin
Mix chemicals as instructed
Plan time for cleanup
©USDA
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17. Recap
Food scientists develop new food products and better methods of preserving and preparing food through experimentation
Using proper measuring equipment and techniques are crucial during food science experiments
Avoid accidents by following all lab safety procedures at all times
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18. Recap The steps of the scientific method are to ask questions
define the problem
conduct research
state the hypothesis
design the experiment
conduct the experiment
evaluate the results
report the results