Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
64 Cards in this Set
- Front
- Back
|
Dedicated to the engineering processes related to food production
|
Food Engineering
|
|
|
Not normally the work of a food engineer
|
Genetic Engineering
|
|
|
Mass In =
|
Mass Out + Accumulation
|
|
|
Means that the mass that enters a facility (raw materials) equals the mass that leaves a facility (product plus waste)
|
Conservation of Mass
|
|
|
Study how foods undergo various process and use the principles to optimize processing systems
|
Engineers
|
|
|
Energy In =
|
Energy Out + Accumulation
|
|
|
States that energy cannot be created or destroyed; it can only be changed from one form to another
|
Law of conservation of energy
|
|
|
Units of measure for energy
|
British Thermal Unit (BTU) or
kilo Joules (kJ) |
|
|
4 Basic Principles of Food Engineering
|
Mass balance
Energy balance Heat transfer Mass transfer |
|
|
Unit used to measure heat, 1 is the amount of heat to raise 1 gram of water 1°C
|
Calorie
|
|
|
heat transfer from molecule to molecule (frying pan to eggs)
|
Conduction
|
|
|
Temperature gradient from high to low
|
Conduction
|
|
|
Forced convection uses a fan or pump to move the fluid
|
convection
|
|
|
transfer of heat between liquid or gas and solid surfaces (fire to frying pan)
|
convection
|
|
|
transfer by electromagnetic radiation (sunlight or microwaves)
|
radiation
|
|
|
the transmission of energy from a highertemperature object to a lower temperature object
|
Heat transfer
|
|
|
common examples of processes that use heat transfer
|
Pasteurization and freezing
|
|
|
Associated with motion and is one of the two basic forms of energy
|
Kinetic Energy
|
|
|
the other form of energy and is associated with position or proximity to other systems
|
Potential Energy
|
|
|
Two Terms for Energy Balance
|
Kinetic and Potential Energy
|
|
|
unit measure, 1 is 239 calories
|
kilo Joule
|
|
|
unit measure, 1 is 252 calories
|
BTU
|
|
|
the rate of heat transfer through a unit of thickness
|
Thermal Conductivity
|
|
|
True False: Foods with less water have more conductivity
|
False: more water
|
|
|
In a microwave the dipole of water responds to the fluctuating electrical field by generating _____
|
friction
|
|
|
Materials that transmit heat readily
|
Conductors
|
|
|
Materials that resist heat transfer
|
Insulators
|
|
|
The opposite of thermal conductivity (related to the insulation value or R-value of materials)
|
Thermal Resistivity
|
|
|
The amount of heat energy necessary to speed up a material’s molecules enough to raise the temperature of a unit mass of a material by 1°C (measured in calories)
|
Heat Capacity
|
|
|
The ratio of the heat capacity of a food to that of water
|
Specific Heat
|
|
|
True False: lower specific heat values heat more quickly
|
True
|
|
|
Air has a spcific heat of
|
.25
|
|
|
Water has a specific heat of
|
1
|
|
|
Equipment used to either add or remove heat from food
|
Heat Exchanger
|
|
|
In frying, conduction occurs within a ____ food while convection occurs between the food and ______ ____
|
solid
cooking oil |
|
|
the dividing line between dissimilar materials
|
Boundary layer
|
|
|
True False: in frying there is a migration of oil into the food and moisture escapes into the oil
|
True
|
|
|
Mass transfer involves the transport of ________________ within physical systems
|
atoms and molecules
|
|
|
4 Examples of Mass Transfer
|
Separation of components by distillation
Diffusion of salt Water Evaporation Membrane filtration |
|
|
The field concerned with evaluating thermodynamic properties of mixed gases present in air
|
Psychrometrics
|
|
|
Three physical properties of air that are important to Psychrometrics
|
Dry bulb temperature
Wet bulb temperature Relative humidity |
|
|
An application of this field is in the evaporation of water from food where the wet bulb temperature is useful for calculating drying rate
|
psychrometrics
|
|
|
The heat input that results in a change of state (freezing/melting and boiling/condensing)
|
Latent heat
|
|
|
Change that can be detected by touch
|
Sensible Heat
|
|
|
Four Food Engineering Applications
|
Rheology
Water management Energy use Handling processing wastes |
|
|
the study of flow and deformation characteristics of foods
|
Rheology
|
|
|
Altering food structure
Designing processing equipment Stabilizing suspensions Product development |
4 Things related to Rheology
|
|
|
The friction within a fluid that prevents it from flowing freely(Ketchup)
|
Viscosity
|
|
|
Homogeneous mixtures that show no change in viscosity as shear rate is increased (linear)
|
Newtonian Foods
|
|
|
Water, juice, soda, oils
are what kind of foods |
Newtonian Foods
|
|
|
Heterogeneous mixtures that change (thinning or thickening) as shear rate is increased
|
Non-Newtonian Foods
|
|
|
Egg whites, Mayonnaise, applesauce, chocolate syrup are
|
Non-Newtonian Foods
|
|
|
occurs when flow rate or velocity is low
|
Laminar Flow
|
|
|
occurs when flow velocity increases to mixing and eddy currents in the fluid
|
Turbulent Flow
|
|
|
Viscosity is measured using instruments called
|
viscometers
|
|
|
Water is used for
|
Cleaning
Cooling/heating Food component |
|
|
Water treatment options
|
Filtration
Chlorination Boiling UV or ozone treatment |
|
|
Energy purposes in food processing
|
Food preservation
Packaging Storage |
|
|
About____ of the energy is used for converting raw materials into products
|
half
|
|
|
Food Processors that generate a significant amount of waste
|
Canneries
Wineries Meat packing companies Cheese manufacturers |
|
|
Three uses for waste
|
animal feed
lactose and whey compost |
|
|
solid wastes unsuitable for feeding
|
Compost
|
|
|
solid or dried wastes from plant or animal processing
|
Animal feed
|
|
|
liquid waste from cheese making
|
Lactose and whey products
|
