open system
matter and energy exchange
closed system
only energy exchange
isolated system
no exchange
system
finite quantity of matter or prescribed region of
space enclosed by a boundary
density changes with
temp and pressure
physical properties of food
density
particle size
moisture content
water activity
acidity
surface activity
viscosity
Density can be measured with
pycnotmeter/hydrometer
true density
density of a pure substance
apparent density
density of substance, including pores
bulk density
density of material when packed in bulk
particle size affects
production and handling
formulation and processing
functional properties and quality
moisture content
amount of water in a sample
water activity
availability of free water in a product
acidity
measure in ph
below 7 acidic
7 neutral
above 7 basic
limiting factor for the growth of botulisum
ph 4.6
acidified foods
Low-acid foods turned into acid foods
low-acid food
above 4.6 pH
high acid food
below 4.6 pH
surface activity
callodial systems in food
emulsion
foams
gels
sols
viscosity
Resistance of fluid to flow when u apply force or shear stress
newtonian fluid
follows Newton’s law
The slope of the shear stress
versus shear rate is constant
non-newtonian fluid
doesn’t follow Newton’s law
shear thinning or shear thickening
nova classification
unprocessed
processed culinary ingredients
processed foods
ultra-processed foods