Scientific Evaluation: Being Objective Chapter 2 Scientific Evaluation: Being Objective

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. continued

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 ©zebrik/Shutterstock

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

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

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

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 ©Goodheart-Willcox Publisher

Measuring Time Measured in seconds Appoint someone as timer Failure makes experiment invalid

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

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 continued

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 continued

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 continued

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 continued

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 continued

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 continued

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 continued

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 continued

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