Chapter 2 Scientific Evaluation: Being Objective Images shutterstock.com 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. Measuring Volume • 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. Measuring Time • Measured in seconds • Appoint someone as timer • Failure makes experiment invalid © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. The Scientific Method • Evaluate 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 continued conclusion and reveal need for further research © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 continued multiple studies of the same issue © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. ©USDA continued Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. 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 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.