Food Engineering Flashcards
Food Processing/Engineering
Promotes desirable changes of nature and form
Prevents undesirable changes
Finished Product =
Vary comp + Ingredients
+ Appropriate processing
Definition of Food
An aqueous mixture of proteins, carbs, lipids, vit, min, colorants, enzymes
Constituents of food are produced by
cellular processes
Def of Engineering
The application of scientific and mathematical principles to practical ends such as the design, manufacture, and operation of efficient and economical structures, machines, processes, and systems
Food Engineering def
The application of scientific and mathematical principles to design, manufacture, and operation of efficient and economical structures, machines, processes, and systems for processing food
Food Engineering deals w (2)
- Theory of transport phenomena
1. Thermodynamics of food systems to monitor and control the processing of food material
Transport Phenomena Theory
Heat, mass, and momentum transfer during processing of food material
Tool Box of Production
Raw materials
- -> tools
- –> finished product
Law of Conservation of Mass
Mass cannot be created or destroyed
Input = Output + Accumulation
Law of Conservation of Mass applies to (3)
total material
ind constituents
chem groups & elem
Law of Conservation of Energy
Energy cannot be created or destroyed
1st Law of Thermodynamics
Energy accumulation = heat input - work
Differential Momentum Balance equation
rate of momentum in - momentum out + sum of forces = rate of accumulation of momentum
Latent Energy
liquid to solid
vapor to solid
solid to vapor
Mass conversion is between
physical change of state
chemical fermentation
Sensible energy
vapor gas
Chemical Rxn of Starch
starch –> glucose –> alc
Chem Rxn of Polyphenols
Polyphenols –> Tea color
Cem Rxn of Sugar
Sugar –> Caramel color
Fermentation product of glucose
alc
Fermentation product of lactose
lactic acid
Fermentation product of sugar
CO2
Mass Transfer is between
Molecular Diffusion & Convection
Mass Transfer of French Fry
Oil & heat go in
Water comes out
Mass Transfer of Tea
Tea goes in
Water vapor comes out
Molecular diffusion
the transfer or mvmt of ind molecules through a fluid by means of random, ind movements of the molecules
Ex. Towel drying
Convection
Mass transfer by convective flow of a fluid flowing by a solid surface or another immiscible fluid
Ex. blow drying hair
Energy Conversion is between
Chem, therm, elec, mechanical chem, therm, elec, mech
Is energy conversion in a car efficient
no, uses less than 15% of available energy in fuel
Energy conversion in a Car (beginning w chemical)
Chemical to thermal
Thermal to Mechanical
Boiler
Chem energy to thermal energy
Thermal energy provides sensible & latent energy for steam production
3 Modes of Energy Transfer
Conduction
Convection
Radiation
Microwave energy?
Conduction
Transfer of energy of motion between adjacent molecules
Heat conduction in cooking medium
oil > water > air
Convection
Transfer of heat/energy by mvmt of molecules & circulation of hot air/liquid resulting from the change in density when heated
Types of Convection (2)
Natural flow
Forced (aided flow)
Forced convection
a fluid is forced to flow past a solid surface by a pump, fan, or other mechanical means.
ex. blow drying
Heated air/water develops
currents that spread heat through the energy
What shortens baking times in convection oven
accelerated air mvmt
Radiation
Direct method of heat transmittances
Heat transmitted as electromagnetic waves or rays
ex. Broiling
Microwave Energy steps
Vibration –> Friction –> heat within the food
Microwave Energy is a result of
rapid vibration of water, fat, or sugar
Microwave heating is combo of
conduction & convection
Momentum
power of a body to overcome resistant by means of motion
M = mv
Simple v Simultaneous Mass & Energy transfer
Simple = 2 step transfer Simultaneous = 1 step
Major 19th-20th century developments in food processing (11)
canning pasteurization Iron roller milling Freezing/refrigeration fermenation food extrusion food irradiation Freeze drying/Drying Organic food Food packaging Food laws & reg
21st century developments in food processing (5)
High pressure processing Pulsed electric field processing Processing w Pulsed light Processing w Ultrasound Dielectric, ohmic, & infrared heating
new frontiers in 21st century food (4)
irradiated food
probiotics
GMO
Functional food
