1. Non thermal methods

2. Do I need to refrigerate butter?
Fat-in-water, to water-in-fat emulsion
“Compartmentalization”

3. Food processing Thermal (>95% of foods in US) Non-thermal
Microwave and radio frequency
Ohmic heating
Non-thermal
Irradiation UV
High-intensity pulsed light
Ionizing radiation
Cold atmospheric plasma processing
Physical methods
High hydrostatic pressure (HPP, HHP, UHP, Pascalization)
Pulsed electric fields
Oscillating magnetic fields

4. High pressure processing (high hydrostatic, ultra high pressure)
Chamber
215 Liter volume processor
Packaged
Food + water
High pressure pump
(Flow International)

5. Pressure of 380-640 Mega Pascals (MPa) How much is 400 MPa?
1 atm = 0.1 MPa
Look to the left;
Deepest part of ocean is 110 MPa -
(Flow International)
Slide from S. Knabel

6. Batch process, industrial scale

7. Inactivation of E. coli O157:H7
Before
After
Black et al., J. Appl. Microbiol. 108:1352

8. HPP treated beef: fresh, frozen, cooked
P. Picouet, M. Pérez-Juan, and C.E. Realini , 2008
Top view
Side view
Slide from Dr. Catherine Cutter

9. But… Slide from Dr. Catherine Cutter Eastern Meat Packers Assn.
Christopher R. Raines
27 Sept. 2011

10. The good and the bad Advantages: Disadvantage:
Inactivates fungi>gram negative>gram positive
Works well with “compressible” foods (sauces, jellies, guacamole, etc);
“Fresher” flavor;
Viewed as less “processed”
Disadvantage:
Doesn’t work with “fragile” foods;
Damages cells of biological tissue (fruits, vegetables, meats);
Doesn’t work well with some fatty foods (adiabatic heating = 3 C per 100 MPa);
Doesn’t inactivate spores very well
(Niche market technology)

12. UV treatment CiderSure UV system Validated to achieve 5-log reduction
Thin film allows efficient flow through
Rate automatically adjusted based on absorbance coefficient of juice
Escherichia coli O157:H7 and Cryptosporidium parvum
Slide from L. LaBorde

13. Sensor regulates pump flow
Flow control
UV-A: nm
UV-B: nm
UV-C: nm
Sensor regulates pump flow
UV bulb
Slide from L. LaBorde

14. Mechanism of inactivation
UV-C

15. Factors impacting UV effectiveness
Turbidity
Presence of UV absorbing molecules
Microbial species
Implicit factors - photolyase
Organism
Exposure required (J/m2)
Adapted first
Escherichia coli
50-100
Salmonella sp.
P. aeruginosa
110
190
Mycobacterium smegmatis
200
270
Rotavirus
350
Not applicable
Ramaiah D et al. PNAS 1998;95:

16. Irradiation
Gamma rays: emitted from nucleus of cobolt 60 or cesium 137
X-rays: generated by reflecting high-energy stream of electrons off a heavy metal such as Tungston or Tantalum
Electron processing beam: “Electron gun” (high energy electron accelerator) focuses
Wikipedia

17. Radiolysis of water Gray = 1 joule/kg
Gray = 1 joule/kg

18. Microbial kill by irradiation

19. Radicidation: removal of pathogens Radurization: prolong shelf life
Delay fruit ripening
Radicidation: removal of pathogens
Radurization: prolong shelf life
“Radura”

20. Advantages/disadvantages
Proven technology;
More even and able to penetrate than heat;
Less costly to operate than heat processing;
Disadvantages
Initial expense;
Dairy, meats, sensitive to oxidation;
Low doses sometimes required aren’t effective against spores, viruses;
Consumer acceptance.

21. Food processing Thermal (>95% of foods in US) Non-thermal
Microwave and radio frequency
Ohmic heating
Non-thermal
Irradiation UV
High-intensity pulsed light
Ionizing radiation
Cold atmospheric plasma processing
Physical methods
High hydrostatic pressure
Pulsed electric fields
Oscillating magnetic fields