Food Science 1Unit 3

Scientific Method

Science: the systematic knowledge of natural and physical phenomena.

Phenomenon: a fact, occurrence or process that can be observed.

Scientists watch what happens under controlled conditions, to determine why things happen as they do.

From study and observation scientists can discover the predictable behavior patterns of the natural world.

For success in the food science laboratory basic guidelines should be followed. Avoid biases, base conclusions on what truly happens, take accurate measurements , observe carefully, keep detailed records, etc.

Scientific Method: Evaluation - Being Objective

Applied science: the process of putting scientific knowledge to practical use.

Experiment: a controlled situation that allows a scientist or researcher to determine what causes a change to occur. (ex. the best way to prepare something)

Formulations: recipes in food science.

Replicable: repeatable

Scientific Method:Food Science in Industry

To take accurate measurements: ◦ Identify what system of measurement or standard

you are using.◦ Determine what your are tying to measure◦ Decide what method of measurement will give you

the most consistent results.

To help scientists all over the world share information an international system has been developed based on metric system – International System of Units (SI)

Units measure mass, length, volume, time and temperature.

Scientific Method:Measurements

Mass: measure of the quantity of matter.Gram (g) the mass of 1 cubic centimeterKilogram (kg) the mass of l liter of water at 4

degrees C (39 degrees F) One kg = 1000 g.Weight – the measure of the force of gravity

between two objects. May change with location.For accuracy scientists need measurement that

does not change from place to place. Massing compares the substance to a standard

mass.

Scientific Method:Measurements - Mass

Triple beam balance – works on same principle as a seesaw- same on both sides balances – gravity the same no matter where location.

Electronic balance – faster, easier to use◦ Calibrate - to adjust measuring instrument to a

standard.◦ To calibrate electronic balance, must measure a

standard mass first, the balance will then compare all substances measured to that mass.

Scientific Method:Measurement – Mass (cont.)

Length: the distance between two points

Meter: the standard unit of length in the metric system. ◦ One meter = 39.27 inches◦ You will usually record length measurements in

centimeters and millimeters◦ One micrometer = 0.000001 meter.

Scientific Method:Measurements – Length

Volume: the amount of space occupied by an object. Volume is a measurement derived from length.

Liter: metric unit for measuring fluid volume. Beaker: a deep, wide-mouthed container with a

pouring lip used to hold substances during experiments.

Erlenmeyer flask: a flat-bottomed, cone-shaped. Graduated cylinder: tall container used to accurately

measure the volume of liquids to the nearest milliliter. Buret: graduated glass tube with a control valve at the

bottom, used to pour an accurate amount of liquid. Meniscus: curve at the surface of a liquid.

Scientific Method:Measurements – Volume

How to measure volume:◦ Place container on a level surface

- Holding at an angle alters the reading

◦ Read volume at eye level- Viewing at an angle will make the liquid

look larger than it really is

Scientific Method:Measurements – Volume (cont.)

Time – in most food science experiments time will be measured in seconds.◦ Record start and stop times using a clock or

watch.◦ Failure to monitor time accurately can invalidate

the experiment.

Scientific Method:Measurements (cont.)

Temperature: measure of heat intensity.◦ Celsius temperature scale – based on boiling and

freezing points of water. Water freezes at 0 degrees C Boils at 100 degrees C

◦ Celsius degree – 0.01 of the difference between boiling and freezing.

◦ Fahrenheit – most commonly used in the U.S. Most lab thermometers marked with both Celsius and

Fahrenheit scales. Always specify units being measured.

Scientific Method:Measurements (cont.)

Scientific Method: system of steps used to solve problems.

Scientific Method

Step 1 - Forming a hypothesisPossible explanations for questions and problemsDefinition: testable predictions that

explain certain observations – an educated guess.

•What am I trying to prove?•What questions do I want to answer?

Scientific Method (cont.)

Step 1 – Forming a Hypothesis(cont.)To form a hypothesis, you use inductive and deductive reasoning skills.

•Inductive – drawing a general conclusion from specific facts or experiences.

•Deductive – works in the opposite direction. You reach a conclusion about a specific case based on known facts

and general principles. * “if/then” statements* the known fact (“if”) leads to a

logical conclusion (“then”)

Scientific Method (cont.)

Step 1 – Forming a Hypothesis (cont.)

Repeat the experiment to see whether results are consistent. If the results are consistent, you may draw valid

conclusions from them.

Scientific Method (cont.)

Step 2 – Experimentation

The heart of the scientific method. Definition: a way to test a hypothesis in order to

verify or disprove it. • Identify and create the conditions that put their

hypothesis to the test. • Includes :

* List of equipment *Materials *Procedure that gives step-by-step instructions and how

to use these items and record results

Scientific Method (cont.)

Step 2 - Experimentation (cont.)

Controlling variables Definition of variables: factors that can change in a n

experiment By controlling all the variables except one, you get more

reliable results Independent variable – a factor that you change Dependent variable – a factor that changes as a result of

the independent variable

Scientific Method (cont.)

Step 3 - Analyzing Data◦ Data – the information gathered during an

experiment.◦ The Data Table – scientists arrange data in a clear

and logical form.◦ Repeat the experiment to see whether results are

consistent. If the results are consistent, you may draw valid conclusions from them.

Scientific Method (cont.)

Step 4 – Reporting the Results

◦ The Report Form – to learn as much as possible form an experiment, you need an organized format for reporting laboratory results.

Scientific Method (cont.)

Step 5 – Developing and revising theories◦ “No amount of experimentation can ever prove me right;

a single experiment can prove me wrong.” – Albert Einstein

◦ Good science is a cycle of observing, proposing a hypotheses, and experimentation.

◦ A hypothesis that is consistently verified may be established as a theory.

◦ Definition of theory: an explanation based on a body of knowledge gained from many observations and supported by the results of many experiments.

◦ A hypothesis is a possibility; a theory is a probability.◦ A theory may be refined, broadened or disproved as new

discoveries are made.

Scientific Method (cont.)

Step 6 – Conducting Research

◦ Investigating what others have learned about a subject.

◦ Research and experimentation complement each other. Choose a topic that interest you and let your

observations spark your curiosity. Narrowing the focus Finding Information

Scientific Method (cont.)

Meta-analysis: when the results of several individual studies are pooled to yield overall conclusions.

When assessing new research, ask the following:◦ Can the study be interpreted in another way?◦ Are there any flaws or biases in the method or

way the study was conducted?◦ How does this study fit in with the current body

of research on the subject?◦ What are the limitations of this study?

Scientific Method:Evaluating Scientific Studies

Remember that the scientific process requires ongoing discussion and debate.

Scientific Method:Evaluating Scientific Studies (cont.)