Innovations in Thermal and Non-thermal processing Flashcards
What drives the innovations in thermal and nonthermal food preservation?
People, policy, process, and climate
Types of Physical Technology
High hydrostatic pressure or (HHP)processing
High pressure homogenization
Types of Electromagnetic Technology
Pulsed Electric Field (PEF)
Ohmic heating
Microwaves
UV-Light (Continuous & Pulsed)
Types of Acoustic technology
Ultrasound
and High Hydrodynamic Pressure-Shockwaves
Other innovation type
Membrane filtration
What is physical technology?
Technologies using pressure
what is pressure?
Pressure is the force per unit
area applied perpendicularly on
a surface; thus, the official unit
becomes Pascal (1 Pa = 1
N/m2).
Define pressure
Pressure is a thermodynamic
parameter that has been possible to
adjust and investigate on biological
systems for the last centuries since
the discovery by Regnard (1884)
Different types of pressure that can be applied
Isostatic pressure- pressure is the same all over the
product and surroundings
Nonisostatic pressure- pressure gradient is induced
Dynamic pressure- extreme high pressure (HP) is
developed over a short time
High Hydrostatic Pressure (HHP) processing
Isostatic pressure increase
in a fluid due to
compression of the fluid
and generally relies on the
application of pressures in
the range from 100 to 700
MPa in the food-processing
context
HP equipment
consists of?
a
cylindrical pressure
vessel and a
pressurizing unit.
In
HP equipment, the
pressure build-up will
be generated by
Direct or indirect method
Direct pressurization
A piston located within the
vessel is the pressure
intensifier and is used to
deliver the HP in the pressure
chamber by mechanical volume
reduction.
Indirect pressurization
Pressure in the chamber is
increased by an HP pump
separated from the vessel and
used to deliver the pressure by
means of pumping the
pressuring medium into the
pressure vessel.
The pressure treatment is often termed
nonthermal
technology or cold preservation
High Pressure Homogenization
Technology that uses a class of
processing equipment referred to as
homogenizers that was geared
toward reducing the size of droplets
in liquid-liquid dispersions.
The homogenization
process utilizes
the
dynamic pressure
generated by a moving
fluid.
What is the difference between 1-stage and 2-stage homogenization?
In 1-stage homogenization, the mean size of particles is 5 micrometers but there is clustering while in 2-stage homogenization, the mean particle size is 5 micrometers but there is not clustering.
______ become a standard
industrial process in the
milk industry.
Homogenization
homogenization has
become a standard
industrial process in the
milk industry
can affect the physical
properties of food media.
It can be an alternative
method for food
pasteurization.
Ultrasound
US can be applied to a
product by different types
of equipment, including
sonication baths,
ultrasonic probes, and
vibrating systems
Limitations of ultrasound
Sensory alteration, challenges for industrial scale application, and microbial growth
is the motion of fluids
and the resulting dynamic
force, and generally relies on
the application of SWs or HP
waves up to 1 GPa.
High Hydrodynamic Pressure
(HDP)
Uses electric fields to
eradicate food-borne
pathogens & to control
spoilage microorganisms
in foods. It is the
application of highvoltage
pulses to food
matrices by means of
two electrodes.
Pulsed Electric Field (PEF)
PEF food preservation is based on
the ability of highintensity
pulsed electric fields to disrupt cell membranes,
resulting in a lethal effect on the microorganisms.
PEF has been applied for the processing of
liquid and
semiliquid food matrices,
Ohmic heating
process in which electrical
current passes through a food product having an
electrical resistance, also described as “resistance
heating,” “electroconductive heating,” or “Joule heating”
The underlying principle of OH is the
dissipation of
electrical energy in the form of heat using an electrical
conductor.
The lower the
conductivity of the material, the higher electrical
field strength it requires.
True
first
envisioned the primary application
of MWs in food entities and filed
his first patent
Percy L. Spencer
MW energy has been
used in
pasteurization
and sterilization as well
as in drying, thawing,
tempering, blanching,
and even combined to
freezing
In food matrices, MW heating is
mainly related to
the mediated
dipolar and ionic mechanisms
the driving force and
the dominant reason of the lethal effects of MW
radiation on the microbial population in foods are
the thermal phenomena.
Four subdivisions of UV radiation
UV-A
UV-B
UV-C
Vacuum UV
what subdivision of UV radiation is involved in food preservation technologies which is
considered as germicidal range as it can effectively inactivate
bacterial, fungi, viral, and protozoan microorganisms.
UV-C
used to
separate particles from a
liquid and to purify it.
Membrane Filtration Technique
During MF process, a solvent is
passed through a
semipermeable
membrane
The main drawbacks of
MF techniques are
mainly attributed to the
fast reduction of
permeate flux and
cleaning
