Science Platforms > Food
Processing
Platform Mission: Investigate the physical/microbial
effect that processing
steps have on preventing
potential public health
hazards in a food product.
(Completed Research Projects)
Convenience, novelty, product
line diversity, improved
quality, shelf life, and safety are all driving forces to incorporate
process technology in the manufacture
of food products. The challenge
is to meet marketing, operating, safety, and quality goals while
maintaining an economical process.
When it comes to safety,
there are a wide range
of technologies that food manufacturers now have at their disposal
such as UV irradiation, novel thermal
processing technologies
including microwave heating, and high-pressure processing. When
evaluating the safety of a process, it is important
to be able to assess the
effectiveness of the process as impacted by the process control
parameters.
This allows the food manufacturer
to target other important
economical aspects of the process while maintaining the necessary
level of safety.
CASE STUDY: Microwave Pasteurization
of In-Shell Eggs
The intact shell of an
egg is still considered
one of the best devices
for preventing the contamination of the egg itself. However, it
is now known that not all laid
eggs are void of pathogenic microorganisms, and it is estimated that 118,000
illnesses per year are caused by consumption of Salmonella enteritidis (SE)-contaminated
eggs. The egg safety action plan by FDA and USDA includes the goal of elimination
of SE illnesses by 2010. To meet that goal, it is necessary to develop a process
to pasteurize in-shell eggs for SE without affecting their functional properties.
In a collaborative research project with the Michigan Research Institute, NCFST
is using techniques they had previously developed to evaluate the effectiveness
of a microwave heating process for in-shell eggs. This includes temperature mapping
of the thermal profiles developed within the egg and actual microbial challenge
studies of the process. Current in-shell egg thermal pasteurization technology
uses batch hot water immersion, and the process can take from 50 to 75 minutes.
Microwaves can rapidly provide the thermal energy required to eliminate SE, drastically
reducing the come-up time in existing in-shell pasteurization processes while
maintaining egg functionality.
Processing Technologies and Applications
- Microwave pasteurization
and sterilization
- High-pressure
processing for extended
shelf-life refrigerated
foods and shelf-stable foods
- Aseptic
processing
of foods containing
particulates
- Ultraviolet
light irradiation of
juice and fluid food
products
- Cold plasma surface treatment
- Biocontainment
Pilot Plant
Facility--under construction
Processing innovations
and activities
Validation of the effectiveness
of a process to deliver
the treatment necessary to eliminate the threat of a public
health hazard from a food product’s
organism of concern can at times be difficult. Often there are no proven procedures
that can be immediately applied to the novel processing technology, which means
that validation procedures must be developed and tested. NCFST has a long history
of working with pathogenic and surrogate microorganisms, both within the laboratory
environment and the pilot plant arena. Microbial validation of food processing
systems with Clostridium botulinum spores and its toxin, Salmonella, Escheria
coli O157:H7, and Listeria monocytogenes, are routinely conducted.
Process equipment used to pasteurize, extend the shelf-life, or sterilize foods
available at the NCFST include a 35-liter high-pressure processing system, numerous
UV light systems for liquid foods, microwave heating systems, traditional thermal
processing equipment, and aseptic processing equipment.
Proven food processing systems and their application
- Microwave pasteurization of in-shell eggs
- UV processing
of juice products
- Monitoring
procedures for sprout
manufacturing
- Resistance
kinetics for HPP Clostridium
botulinum spores
- Thermal kinetics of Clostridium
botulinum spores
and its toxin and
numerous vegetative pathogens
- Thermal
profile of aseptically
processed particulate
foods
- Validation
protocols
for aseptic systems
- Lethality
based process
control
systems
- Validation
of software-based
computer
systems
- High pressure
processing
of
shelf-stable low-acid canned
food
products
