NOVEL FOOD PROCESSING TECHNOLOGIES:

Emerging Applications, Research and Regulations

Tatiana Koutchma, PhD.

Guelph Food Research Center

2

AAFC FOOD SAFETY RESEARCH

2010

•CL-02 pilot plant in Guelph

•$1.2 mln Modernizing Federal Labs Initiative

•Official opening on November 9, 2010

•Certified as CL-2 on March 23, 2011

•Research activity started in summer 2011

•Microbiological

•Toxicological

•Chemical safety

•Opens opportunities to food safety engineering research

3

GFRC PILOT PLANT: CL-02 Certified Facility

20092010

2011

PHAC certification

Objective

• Review – Available groups of food high -techs

• Provide– Information to assist in evaluation of relative capabilities of commercially

available technologies and technologies-in-development to ensure safe and nutritious foods.

• Discuss– Risk based approach for establishing a safe process

• Research Highlights– UV light – Microwave heating– Pulsed Electric Fields

Food High Tech Processing

• Emerging in primary food production and processing – Transform raw materials into food products– Preserve fabricated foods and ingredients during

transportation, retailing and consuming foods.

• Provide Safety attributes higher than those of raw products

• Maintain Health and Quality attributes at least equal to raw products

• Enhance Functional properties

• Provide Broader Sustainable and Environmentally friendly benefits

5

6

Key Drivers• Freshness & Convenience & Less preserved

• Enhanced Safety and Extended Shelf-Life

– Pathogen reduction in fresh produce

– Listeria post-lethality treatments

• Heat labile functional ingredients

• Engineering functional ingredients for delivery of healthy foods

• Lower carbon footprint and reduce water volume used in heat transfer processes

• Need for sound regulatory policy – U.S., Canada, EU

Microbial Food Safety

AcidificationWater activityPreservatives

Chemical

RefrigerationFreezing

Physical

InhibitionSpoilage

HeatDielectric heating

Ohmic heatingPEF

Thermal

IrradiationUV light

High Pressure

Nonthermal

Pasteurization

HeatHigh Pressure + heat

Dielectric heating

Thermal

GammaIrradiation

Non-thermal

Sterilization

InactivationSpoilage

Pathogenicm/o

Food Preservation

Classification of foods categories and post-processing storage conditions

FoodsCatego

ries

Shelf-StablepH>4.6

Acid & Acidified

3.5<pH<4.6

High AcidpH<3.5

Sterilization

Pasteurization

Refrig

eratedS

torag

e+

Gro

wth

inh

ibitio

nb

arrierL

AP

Fs

ES

L

Am

bien

tS

torag

e

LA

F

Pasteurization

Pasteurization

Am

bien

tS

torag

e

Am

bien

t+

barriers

&C

hilled

Fo

od

sE

SL

Sterilization

Process to remove or destroy all viable forms of microbial life, including bacterial spores

– Long term preservation

– “Commercial Sterility”

– Packaging & storage environment will prevent growth of microorganisms of public health concern & spoilage type

• Food Safety Objective (FSO) Approach

Pasteurization

• Prior to 2002 FDA considered pasteurization as a thermal treatment

– FDA would not allow a nonthermal processing technology to promote its treatment as a “pasteurization” process

• September 2004, the USDA National Advisory Committee on Microbiological Criteria for Foods (NACMCF) redefined the term pasteurization

Any process, treatment, or combination thereof, that is applied to food to reduce the most microorganism(s) of public health significance to a level that is not likely to present a public health risk under normal conditions of distribution and storage

Food Chemical News, 2004

Examples of pasteurization process for products within different pH-groups

Examples ofProducts

pH Pathogen of Concern

RequiredReduction

(Logs)

EnzymesDestruction

Apple cider <3.5 E. coli O157:H7 5-log 10

Orange juice <3.5 Salmonella,E. coli O157:H7

5-log10 Pectin-methylesterase

Carrot juice >4.6 non-proteolytic C.botulinum 5-log10

Milk and milk products

~6.5 -7 Mycobacterium tuberculosis;

Coxiella burnetii

5-log10 Negative for alkaline phosphatase

Eggs products >7 Salmonella enteritidis; Salmonella

typhimurium

7-log10

In-shell eggs >7 Salmonella 5-log10

RTE meals >4.6 Listeria 5-7 log10

Almonds Salmonella 5-log10

Fish and sea products

>4.6 non-proteolytic C.botulinum 6-log 10

Crab meat >4.6 Type E non-proteolyticC. botulinum

12-log10

12

Food Technology Assessment

Technology Readiness Level (TRL)

Description

1 Basic principles observed and reported

2 Technology concept and/or application formulated

3 Analytical and experimental critical function and/or characteristic proof of concept

4 Component validation in relevant environment

5 System or prototype demonstration in relevant environment (pilot scale)

6 Systems available commercially

7 Economic feasibility demonstrated or regulatory issues addressed (but not both)

8 Economic feasibility and regulatory issues addressed

9 Ready for full-scale commercialization

13

Thermal TechnologiesTraditional (9)

• Canning – in package retorting

• Aseptic Sterilization

– Package in sterile conditions-Cool

• Pasteurize - Package – Cool :

– “Hot-Fill” Technique

• Pasteurize - Cool – Package :

– “Cold-Fill” Technique

• Package - Pasteurize - Cool :

– "Sous vide’ Technique

Novel/Emerging• Pressure + Heat (8)

• Radiative or Microwave dielectric (8)

• High frequency (HF) or Radio Frequency (RF) dielectric (5-6)

• Infrared (6-7)

• Ohmic heating/Conductive (5-6)

14

Knowledge in Thermal Processing• Established organism of public health concern

• Understood the destruction kinetics/mathematics necessary to evaluate a treatment

• Developed knowledge how products heat for given processing systems

• Generated principles on the relationships between the organism of public health concern and spoilage

• Ability to express a complicated process delivery in simple “Lethality” terms so as to understand the equivalent safety of different processing systems

1503/16/2011 (C), 2011 Tatiana Koutchma

Non-thermal Technologies

Emerged

– Irradiation (9)– High hydrostatic pressure (8-9)– Filtration (9)– Ozone (8-9)

Emerging

– Pulsed Electric Fields (6-7)– UV light (6)– Pressure and CO2 (6)

Under development

• Cold Plasma (3-4)• Electrolyzed water (5)• Sonication (5)• Low dose e-beams (5)

16

Future Processing Trends

Traditional Technologies

Improvements in Designs and ControlsRedesign

Improved Manufacturing Performance

Improved Product Quality

Traditional Foods

Novel Technologies

Novel Processes

Transformation & Preservation

Improved Quality Products

Novel Foods

VS

17

Example - UV light Technology

Preservation• UV pasteurization of liquid foods

and beverages

– Fresh juices

– Iced teas, soft drinks

– Liquid Sweeteners

Transformation / Added value§ Milk

Vitamin D synthesis

§ Mushrooms (cultivated and wild grown, lyophilized )

Vitamin D2 synthesis

§ Peanut butter, soy

Potential to reduce allergenicity

§ Carrots

Increased AO capacity

18

Challenges of Novel Food Processing

• Safety Equivalence

Traditional Foods VS Novel Foods

Traditional Process VS Novel Process

19

Novel Foods

20

Global Regulations

NOVEL FOODS

ü European Union

ü United Kingdom

ü New Zealand/Australia

ü Canada

ü China

NO DEFINITION OR OTHER TERMS

ü USA

ü Japan

ü India

21

Novel Foods in Canada

• Foods resulting from a process not previously used for food.

• Products that do not have a history of safe use as a food.

• Foods that have been modified by genetic manipulation,

also known as genetically modified foods, GM foods,

genetically engineered foods or biotechnology-derived foods.

22

Risk Assessment of Safety of Novel Foods

• Details of novel process

• Dietary Exposure

• History of organism

• Nutritional considerations

• Toxicology considerations

• Allergenicity considerations

• Chemical considerations

O

O

O

OH

23

USA

No Novel Regulations

• US FDA considers food ingredients as novel that have not been previously used

• New dietary compounds (NDI)

• As food additives under existing law, the principal law being the Federal Food, Drug and Cosmetic Act.

• The ‘Generally Recognised as Safe’ or GRAS concept is the bench mark by which all foods, including novel foods, are assessed.

• GRAS substances are: substances used before 1958 (excluding prior sanctioned food ingredients); and substances for which there is scientific evidence of safety as determined by competent experts and by published and available safety information.

24

US Approvals of Novel Processes

• 2001, Code 21 CFR Part 179.39 was published to improve the safety of fresh juice products: Source of UV radiation (LPM at 254 nm) defined as a food additive

• 2004, USDA has approved High Hydrostatic Pressure as an intervention method for Listeria contaminated pre-packed ready-to-eat (RTE) meat products

• 2008, 73 FR 49593 The FDA published a final rule that allows the use of irradiation for fresh iceberg lettuce and fresh spinach

• 2009, the US FDA approved a petition for the commercial use of Pressure Assisted Thermal Sterilization process (PATS) for application in the production of LAF

§ 2010, US FDA first time approved novel sterilization processing using 915 MHz microwave energy (MATS) for producing pre-packaged, LAF

25

What Understanding is Needed when Establishing a Novel Process?

A

Process Design Validation

Hazard

Analysis RegulatoryAcceptance

BIngredients Product

ProcessA B

B

26

UV Technology

• UV light for Food Safety in Food Plants

• Novel UV Preservation Processes

Research Approaches and Results

Novel Taylor Couette UV reactor

Novel pulsed UV sources and foods quality

Toxicological safety of apple juice

• Future Needs

Why UV?• Effective against microbial and chemical hazards

• Physical non-thermal method

• Chemicals free

• Cost effective

• Energy efficient

• Approved by Regulatory Agencies

– EPA– US FDA (2001)– Health Canada (2003)

2011201020092008200720062005200420032002

25

39

33

38

33

23

12

171614

UV light

Food Safety

Non-Food Contact

Food ContactSurfaces

Air

Preservation

Pasteurization

Shelf-Life Extension

Juices

MilkFresh Produce

Transformation

Toxins

Allergens

Peanuts

Peanut ButterSoy

Value Added

Nutrients enhancement

MushroomsMilk

Carrots

UV Sources• Continuous - Monochromatic

– Low Pressure Mercury (LPM) 102-103 Pa– Low Pressure Amalgam lamps (LPA) – high output– Excimer Lamps

• Selectable to the wavelength of interest

• Continuous - Broad Band– Medium Pressure Mercury lamps(MPM) 10-30MPa

• Pulsed - Broad Band– Xenon Flash Lamps– Surface Discharge

High intensity (1-30Hz)

• UV LEDs

Comparison of UV sources

UV source Electricalefficiency

%

UV efficiency

%

UV intensity

W/cm2

Lamp surface

T,Deg C

Lifetime,

month

Output Spectrum

LPM 50 38 0.001 -0.01

40 18-24 Monochromatic 253.7 nm

Excimer 10-25 10-30 0.05-0.5 ambient 13 Monochromatic selectable

MPM 15-30 12 12 400-1000

0.5 Polychromatic 200-400 nm

Flash Xenon

Surface Discharge

45-50

15-20

9

17

600

30,000

1000-10000

NA

1

NA

Polychromatic100-1000 nm

Polychromatic200-800 nm

Novel LED Diodes

• Energy-efficient, long life, easy control of emission and no production of mercury waste

• Inactivate by UV photons and creating reactive oxygen species (e.g.H2O2, O¯2 and OH¯) via the photooxidation of O2

• Emission at 265nm ± 15nm

• Output power 4.5 mW

• Anticipate 10mW June 2011

• Lifetime measurements

• >10,000hrs @ 100mA input current • Emission strongly forward focused (±30o)

• Cost is an issue

32

CFR 21 179.39 UV radiation for the processing and treatment of food

Radiated food Limitations Use

Food and food products

Without ozone production: high fat-content food irradiated in vacuum or in an inert atmosphere; intensity of radiation, 1 W (of 2,537 A. radiation) per 5 to 10 ft.

2

Surface microorganism control.

Potable water Without ozone production; coefficient of absorption, 0.19 per cm or less; flow rate, 100 gal/h per watt of 2,537 A. radiation; water depth, 1 cm or less; lamp-operating temperature, 36 to 46 deg. C.

Sterilization of water used in food production.

Juice products Turbulent flow through tubes with a minimum Reynolds number of 2,200.

Reduction of human pathogens and other microorganisms

Food Plant Microbial Hazards

• Airborne

– Molds Spores, human pathogens

• Waterborne

– Viruses, pathogenic bacteria and spores

• Foodborne

– Bacteria, spores

• Spoilage

– Yeats, molds, lactobacilli

UV on Food Plant

• Air and water treatments

• Non-food contact surfaces

• Food contact surfaces

• Food surfaces

OFFERS UV-PROTECTION!

AirPurification to reduce microbial load

• Production facilities air cleaning

• Duct systems

Spores are more resistant to UVGI

Viruses are highly vulnerable

Rate constant of E-coliis 3-4 times its plate value

Non-Food Contact Surfaces

– Facility surfaces• Walls

• Ceilings

• Floors

– UV activated coating

Food Contact Surfaces

– Packaging• films

• caps

• cups, tubes

– Conveyors

– Equipment surfaces

– Packaged Foods

Food Products Surfaces

• To reduce levels of pathogens(Listeria and Salmonella) on meats, poultry, fish

• Salmonella in Shell-eggs

• Extended Shelf-life bakery products

• Fresh Produce

• Food powders • black pepper and wheat flour

Fresh and Fresh-Cut Produce

• Retard microbial growth without causing undesirable quality changes

– Whole Produce: apples, kiwi, lemons, nectarines, oranges, peaches, pears, raspberries and grapes

– Leafy produce: lettuce, salad, spinach– Fresh-cut : watermelon and cantaloupe

• 1-log reduction at 4.1 kJm-2 without affecting juice leakage, color and overall visual quality

» Baulieu, J., 2007; Lamikanra, O. et al, 2005

UV sensitivity on the surfaces: Listeria monocytogenes

• Agar:– D10= 0.5 mJ/cm2

• Surfaces of packaging materials, conveyor belts

– D10 = 2.55 – 3.2 mJ/cm2

• Products– Frankfurters

D10=300 mJ/cm2

– Cut Pear

D10~ 2000 mJ/cm2

40

• Fresh Juices Apple, apple cider, carrot, orangeTropical fruit juices

§ Liquid sweeteners Sucrose, fructose, glucose

§ Ice teas, soft drinks § Liquid egg products§ Milk, cheese milk and calf milk§ Whey protein concentrates§ Brewery & winery

§ Emulsions, brines, marinades

Liquid Foods and Beverages

UV preservation: pHClassification of Fluid Foods

Groups of Fluid Foods

Clear Liquids

EmulsionsLiquid-

ParticlesSuspensions

High Acid pH<3.5

Acid3.5<pH<4.6

Low AcidpH > 4.6

Low AcidpH > 4.6

High AcidpH<3.5

AcidpH<4.6

LowAcid

pH>4.6

Apple Juice

GrapeJuice

Iced teaWatermelon

juice

Liquid Sweeteners

MilkOrange

JuiceCarrotJuice

Tomato juice

LiquidEgg

Products

PineappleJuice

Guava

Groups of Fluid Foods

Clear Liquids

EmulsionsLiquid-

ParticlesSuspensions

High Acid pH<3.5

Acid3.5<pH<4.6

Low AcidpH > 4.6

Low AcidpH > 4.6

High AcidpH<3.5

AcidpH<4.6

LowAcid

pH>4.6

Apple Juice

GrapeJuice

Iced teaWatermelon

juice

Liquid Sweeteners

MilkOrange

JuiceCarrotJuice

Tomato juice

LiquidEgg

Products

PineappleJuice

Guava

Properties of fluid foods

0

10

20

30

40

50

60

70

80

90

100

Ab

so

rptio

n c

oef

fici

ent

per

cm

Water Wastewater

Clearapplejuice

Applecider

Orangejuice

Liquidsugars

0

20

40

60

80

100

120

140

Vis

cosi

ty,

cP

water applejuice

pineapplejuice

liquidsyrup

pH, deg Brix, suspended solids/turbidity

44

Integrated sphere: diffuse transmittanceClear juices

y = 2.6462xapple

y = 2.3998xcranberry

y = 2.2102xgrape

0.0

0.3

0.5

0.8

1.0

1.3

1.5

1.8

2.0

2.3

2.5

0 0.2 0.4 0.6 0.8 1 1.2

Pathe length, mm(a)

A a

t 25

3.7

nm

apple juice

white grape juice

Cranberry juice

Juices with particles

y = 1.119xapple cider

y = 3.9464xorange

0.0

0.3

0.5

0.8

1.0

1.3

1.5

1.8

2.0

2.3

2.5

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Path length (mm)(b)

A a

t 25

3.7

nm

Orange

Apple Cider

Tomato

Carrot

Absorption coefficient

Apple juiceCranberry

White Grape

Apple cider

Orange juice

0

5

10

15

20

25

30

35

40

45

Fruit juice(c)

a. 1

/cm

Absorption spectra

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

220 240 260 280 300 320 340

Wavelength, nm(d)

Ab

sorb

an

ce

Cranberry

Orange

Grape

Apple

Apple cider

Fluid Foods for UV preservation

Non-Lambertian

Non-Newtonian

NL-NN

Lambertian

Non-Newtonian

L-NN

Non-Lambertian

Newtonian

NL- N

Lambertian

Newtonian

L-N

45pH<3.5; 3.5 <pH<4.6; pH>4.6

UV sensitivity

Water

Cryptosporidium

Bacteria Yeasts

Spores

Viruses

(Adenovirus)

UV

re

sist

ance

Liquid Foods

Bacteria

Yeasts

Spores

Viruses

Molds (spores)

UV

re

sist

ance

Depends on wavelength

Emission Spectrum

Depends on product parameters

pH, Aw, composition

UV spectral chart of R52-G lamp

sample

MATERIALS

apple juicebuffer

METHOD

Sample volume: 4 mLSample depth: 2 mLUV fluence: 0.19 mJ/cm2

Identification of surrogate forE.coli O157:H7

UV lamp: R52-G

UV inactivation of E.coli in buffer and juice

48

-6

-5

-4

-3

-2

-1

0

0 5 10 15 20 25

log

10(N

/N0)

UV fluence (mJ/cm2)

Malate buffer pH 3.5

O157:H7

ATCC 8739

-6

-5

-4

-3

-2

-1

0

0 100 200 300 400 500 600

log

10(N

/N0)

UV fluence (mJ/cm2)

Allen's apple juice

O157:H7

ATCC 8739

UV sensitivity of E. coli strains in apple juice

50

UV process Design Approaches for Low UVT fluids

Match • emission spectrum of UV

source to absorptionspectrum of liquid or beverages

• design of UV reactor to create total fluid volume delivery to UV sources– Volume Mixing– Surface Refreshing

0,0

0,2

0,4

0,6

0,8

1,0

1,2

200 220 240 260 280 300 320 340

Ab

sorb

ance

Wavelength (nm)

Mott's Apple Juice Allen's Apple Juice

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

220 240 260 280 300 320 340

Abs

orba

nce

Irra

dian

ce

(mW

/cm

2 /nm

)

Wavelength (nm)

LPM Lamp

HIP-3 Lamp

Apple juice

Vitamin C (1 mg/mL)

Design of UV units for Low UVT LiquidsThin film reactor “CiderSure”Annular reactor “UltraDynamics”

Thin film mixers “Pure UV”/ “Iatros” Static Mixers – Dean Flow “Salcor”

Inlet

Outlet

UV lamp

Teflon tubewound inhelix pattern

L-NL-NN

NL-NN

NL-NN

Experimental set-up: UV TAYLOR – COUETTE FLOW

rotor

Lamp

pump

inlet

outlet

UV lamp: LPM

Lamp power: 3.80 W

Flow regime:1. 1500 ml/min, 0 rpm2. 1500 ml/min, 200 rpm3. 500 ml/min, 0 rpm4. 500 ml/min, 200 rpm

MATERIALS

apple ciderE. coli ATCC 8739

INACTIVATION OF E. COLI ATCC 8739 IN APPLE CIDER PROCESSED WITH T-C UV REACTOR

-7,0

-6,0

-5,0

-4,0

-3,0

-2,0

-1,0

0,0

0 200 400 600 800

log

10(N

/N0)

Residence time (s)

Apple cider - E. coli ATCC 8739

1500 - 200rpm1500 - 0 rpm

500 - 200 rpm0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

0 100 200 300 400

Co

nce

ntr

atio

n o

f N

aCl

(%)

Time (s)

Residence Time of 5% NaCl in Apple Cider in TC Reactor

500(0)avg

500(200)avg

1500(0)avg

1500(200)avg

EXPERIMENTAL SET-UP

Sample

200 mL

Samplevolume:

200 mLSample

6 cm

Sampledepth:

6 cm

CONTROL:non-UV treated

sample

Photography (without front cover) and scheme of collimated beam setup used with the LPM lamp.

A – Collimated beam box; B – UV lamp; C – aperture; D – sample dish

UV fluence:10 mJ/cm2 – mercury lamps (LPM, MPM)

5 mJ/cm2 – pulsed lamps (HIP)

Mercury Lamps: LOW PRESSURE (LPM) ANDMEDIUM PRESSURE (MPM)

LPMmaximum at:

253.27 nm

Light output of LPM and MPM

lamps were measured

at sample position

of 30.48 cm from the centre of the

lamp

-0,05

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

0,45

0,50

200 250 300 350

Irra

dian

ce

(mW

/cm

2 /nm

)

Wavelength (nm)

LPM Lamp

MPM Lamp

HIGH INTENSITY PULSED (HIP) LAMPS

HIP-1Energy/pulse: 31 JPulse rate: 8 Hz

HIP-2Energy/pulse: 344 JPulse rate: 0.75 Hz

HIP-3Energy/pulse: 644 JPulse rate: 0.50 Hz

0,000

0,005

0,010

0,015

0,020

0,025

0,030

0,035

0,040

200 250 300 350

Irra

dian

ce

(mW

/cm

2 /nm

)

Wavelength (nm)

HIP-1

HIP-2

HIP-3

Irradiance of each of HIP UV lamp was measured atsample position: 45.72 cm from the centre of the lamp

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

1,80

2,00

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

220 240 260 280 300 320 340

Abs

orba

nce

Irra

dian

ce

(mW

/cm

2 /nm

)

Wavelength (nm)

LPMLampHIP-3Lamp

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

220 240 260 280 300 320 340

Abs

orba

nce

Irra

dian

ce

(mW

/cm

2 /nm

)

Wavelength (nm)

LPM Lamp

HIP-3 Lamp

Apple juice

30% FRUCTOSE APPLE JUICE

APPLE CIDER MILK

QUALITY PARAMETERS THAT WERE NOT SIGNIFICANTLY AFFECTED (p > 0.05) BY ANY OF THE UV TREATMENTS

30% Fructose

pH (< 5.0)[exception - MPM lamp: > 10%]Soluble solids (< 0.5)

Milk

pH (< 0.5)Soluble solids (< 2.0)Alkaline phosphatase (< 8.0)Viscosity (< 2.0)

Apple juice

pH (< 0.5)Soluble solids (< 0.6)

Apple cider

pH (< 1.5)Color (< 3.0)Soluble solids (< 0.5)Total phenolic content (< 2.5)Antioxidant capacity (< 3.0)Polyphenol oxidase (< 10.0)

UV EFFECT ON COLOR OF FRUCTOSECIELAB color scale

L*

a*

b*

L*

a*

b*

UV EFFECT ON COLOR OF APPLE

JUICE

UV EFFECT ON COLOR

OF MILK

Green (-) – red (+) axis

Blue (-) – yellow (+) axis

Black (0) – white (100) axis

UV EFFECT ON VITAMIN C

IN APPLE JUICE

UV EFFECT ON VITAMIN C

IN MILK

Inactivation of Enzymes• PPO, peroxidase, pectinolytic enzymes in model systems, apple juice and apple fruits

• Alkaline phosphatase in milk

• Trypsin and carboxypeptidase A in buffers

2.5

3.0

3.5

4.0

4.5

5.0

0 10 20 30 40 50

UV dose (mJ/cm2)

PP

O u

nit

s Apple juice

UV-C light ~ 30% destruction

Manzocco, L et al, 2009, IFS and ET

UV-C monochromatic, 3.94 J/cm^2:

~ 40% loss after exposure clear apple juice to

Falguera et al 2010, LWT

Polychromatic UV lamp at 400 W (250 –740 nm) with max at 420 nm

PPO in apple juice 100% inactivated after 100 min of treatment

Patulin control

• Mycotoxin produced by certain species of Aspergillus, Penicillium and Byssochlamys

• Cause acute but more frequently, chronic toxication

• Codex Alimentarius, CFIA & U.S. FDA recommended the limitation of apple products intended for human consumption is 50µg/L (50ppb)

• Structure: [4-hydroxy-4H- furo (3, 2-c)-pyran-2-(6H)-one]

• Peak absorption wavelength: 276nm

.

Patulin-Degradation by UV light

0,00

0,20

0,40

0,60

0,80

1,00

1,20

200 220 240 260 280 300 320 340

Abs

orpt

ion

coef

ficie

nt (

cm-1

)

Wavelength (nm)

Absoption of 10ppm patulin in water with UV exposure

0 s 150 s 300 s 600 s 1200 s

Sample

UV source

Sample

Magnetic stirrer

UV source

Static cuvette system

Dynamic - collimated beam system

v Degradation of patulin followed the first order reaction

v The degradation rate constants were affected by incident fluence rate, sample length, way of mixing and media in which patulin is dissolved

v Maximum UV delivered dose (which degrades almost all patulin, eg. 99.99%) is only associated with the quantum yield, initial patulinconcentration and sample length.

v The time to reach specific level of maximum dose (eg. 50% or 90%), however, decided by the degradation rate constant.

UV - What are PROS?

• Commercially available UV sources present options to solve specific needs of SURFACE and VOLUMETRIC applications

• Offers numerous solutions to food processors to improve Microbiological, Toxicological and Chemical safety

• Low cost non-chemical protection against microbes in the air, water, non-food and food surfaces, pre-packed foods

• As a method of preservation, UV light can be used for fluid foods– to extend shelf-life of fresh produce – as alternative to thermal pasteurization of liquid foods and beverages– to destroy toxins

• Potential to create value-added products

Risk of UV Processes

• Over processing due to UV dose non-uniformity

• Photo-reparation of bacteria due to under processing

• Furan formation

• Migration of packaging compounds

67

Radiative or Microwave Dielectric915 or 2450 MHz

Commercial systems ~ 915 MHzHome systems ~ 2450 MHz

High frequency (HF) or Radio Frequency (RF) dielectric

Electro Heating Techniques

History

• 1921-magnetron was developed by Hill

• 1945-Dr. Spencer built the first microwave oven from a farmers milk can and obtained a patent

• 1955 -the first microwave oven was introdoced by Raytheon Co.

• 1970 Radiation control for Health and Safety Act

• 1974 variable power control were available

• 1984-microwave ovens accounted for the largest annual shipment of any home appliances in history

Basics of MW heating

• MW energy is generated by special oscillator tubes magnetrons or klystrons

• MW energy is transmitted to an applicator or antenna through a waveguide or coaxial transmission line

• MW are guided primarily a radiation phenomenon

• MW are able to radiate into a space which could be the inside of the oven or cavity

Heat is generated volumetrically due to interaction between EM field and

the material

Advantages

§ Volumetric origin§ Reduced processing time§ Improved quality§ Controllable heat deposition§ Selective heating

Limitations§ Uneven heating§ Non isothermal§ A lack of reliable method for food safety

Major Challenges

• Non-uniformity of MW-induced temperature within the product

• Location of the slowest heating point is unknown and varies

• A time-temperature profile of the coldest spot is difficult to measure

• Evaluation of MW process lethality in a geometrical center may be fairly inadequate

Critical limitation for microwave sterilization of LACF

Trace of the Load Coldest Point

3D Migration of Tm(t) within the Load in the Course of MW Heating

Rectangular load: a × b × c = 100 × 76 × 30 mm

Status of Microwave Processing

§ MW heating is well understood from

a physics, food science and engineering

§ Cost of MW equipment has fallen

§ Advances in computer design and

modeling

§ Selective MW heating

of food components can be achieved

Advantageous MW Processes

ü Pasteurizing or cooking high-viscosity, low-acid liquids (pH>4.6 ), liquids with particles

ü Pasteurizing products with fouling problems

ü Pasteurizing heat labile productsüquality optimizationü In-shell eggs

ü MW high temperature - short time sterilization (HTST)

Commercial Applications

• North America– Tempering of frozen foods– Cooking of meat emulsions– Sterilization of sweet potatoes

• Europe– Pasteurization and sterilization of ready-to-eat meals– Cooking of sauces– Drying of particulate foods– Tempering of frozen foods

• Japan– Pasteurization and sterilization of ready-to-eat meals– Drying of particulate foods

Modeling of MW heating

• Microbial destruction – Non-isothermal heating conditions – Lack of temperature control

• Quality degradation – Less thermally degrading

if heats faster and more uniform

• Heating characteristics – spatial and time-temperature curves during transient and steady state– heating rates– absorbed power – coupling efficiency

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

53 57 60 62 65 67

Temperature, oC

Sur

viva

l Rat

io

15

20

25

30

35

40

45

50

Res

iden

ce t

ime,

s

steam

MW

Time-steam

Time-MW

Coupling and Food Properties

MATS Process

§ In February 2010, US FDA first time approved novel sterilization processing using 915 MHz microwave energy for producing pre-packaged, low-acid foods

§ Technology immerses packaged food (mashed potatoes) in pressurized hot water while simultaneously heating it with microwaves at a frequency of 915 MHz

§ This combination eliminates food pathogens and spoilage microorganisms in just 5 to 8 min

§ Chemical markers were used to identify a food’s cold spot

§ Produces safe foods with much higher quality than conventionally processed RTE products

Microwave Process for Pumpable Foods

• Microwave high temperature short time sterilization (HTST)

• Industrial Microwave Systems (915 MHz)

• Delivers uniform heating in a continuous flow

• Sweet potato puree

• Approved process by US FDA

Journal of Food Engineering, 2007, V.85 (4)

Pasteurization of In Shell Eggs

• Eggs can commercially be pasteurized by conduction heating in air or water

• Davidson-Process assures the necessary 5-log-reduction of Salmonella Enteritidis.

• Due to the low heat conductivity of the albumen and the yolk the process time is about 180 min

• For the whole time the yolk and the albumen is exposed to elevated temperatures of up to 57°C.

In-Shell Egg

(Gregory Fleischman, 2004)

k cp

[W/m*K] [kJ/kg*K]

Egg White 67.22 17.54 0.58 3.91Egg Yolk 30.02 9.62 0.40 3

20°C/ 915MHz ε' ε"

Thin Egg White

Thick Egg White

Yolk

Air Cell

Egg Shell

Outer and Inner Membrane

(g per 100g)

Protein 11.95 15.50 9.80Moisture 75.85 56.20 88.55Fat (total Lipid) 10.20 25.60 0.00Ash 0.95 1.55 0.60Carbohydrate 1.05 1.15 1.05

Nutrients Whole Egg Yolk White

Characterisation of In-Shell Eggs

Mass [g]

Fre

qu

en

cy

696663605754

50

40

30

20

10

0

Mean 61,07StDev 3,465N 300

Diameter [inch]

Fre

qu

en

cy

2,402,252,101,951,801,65

70

60

50

40

30

20

10

0

Mean StDev N1,713 0,03706 1202,253 0,06419 120

VariableWidthLength

• Mass: important for predicting microwave heating conditions

Dielectric properties of egg components

albumen, e'

0

10

20

30

40

50

60

70

80

0.00E+00 5.00E+08 1.00E+09 1.50E+09 2.00E+09 2.50E+09 3.00E+09 3.50E+09

55 °C

5 °C

albumen, e"

0

5

10

15

20

25

30

35

40

45

50

0.00E+00 5.00E+08 1.00E+09 1.50E+09 2.00E+09 2.50E+09 3.00E+09 3.50E+09

55 °C

5 °C

5 °C

55 °C

yolk, e'

0

5

10

15

20

25

30

35

40

45

0.00E+00 5.00E+08 1.00E+09 1.50E+09 2.00E+09 2.50E+09 3.00E+09 3.50E+09

55 °C

5 °C

yolk, e"

0

2

4

6

8

10

12

14

16

18

20

0.00E+00 5.00E+08 1.00E+09 1.50E+09 2.00E+09 2.50E+09 3.00E+09 3.50E+09

55 °C

5 °C

D- and F-values of Salmonella Enteridius

[°C] Yolk White Yolk White55 9.8 8.0 49.0 40.0

57.2 3.2 --- 16.0 ---58.3 --- 1.0 --- 5.060 0.7 --- 3.5 ---

Process Temperature F-Value [min]D-Value [min]

Microwave Pasteurization of In-shell Eggs

• Advantages of MW process :• Reduce the CUT• Establish different pasteurization

temperatures for yolk and albumen• Attain less temperature abuse of egg

constituents• Achieve better quality retention

0

10

20

30

40

50

60

0 50 100

150

200

250

300

Time [s]

T-T

i [°C

]

300W 250W 100W 50W conduction heating (59°C)

(C) 2011, Tatiana Koutchma

5-logs reduction of Salmonella , FDAPerformance Criteria

Microwave Pasteurization Process Specification

Time, TemperatureD T-values of Sm

Process Boundary Conditions

Energy Efficiency

UniformHeating

Selected Heati ng

Quality

No denaturation of egg proteins T < 65 CEmulsion stability

Rapid heatingFoam ability

Computer Modeling

Electromagnetic Field Calculations

Heat Transfer

CoaxialWaveguide

Frequency433, 915, 2450 MHz

Cou pling ShapeDimensions

One EggMultiple Eggs

StaticRotationMoving

Manufacturing of MW cavity

Coaxial cavity915 MHz, 300 W

Conveyor915 MHz, 300W

Waveguide915 MHz 6 KW

Validation of MW unit s

Equipment

Waveguide

Micr obial

Waveguide

Quality

WaveguideFunctionalProperties of albumenHaugh Units

Critical process

parametersUniformity

InoculationInactivation

of Sm

(C) 2011, Tatiana Koutchma

MW pasteurizers

Conveyor type 915 MHz, 300 W output power

Cylindrical MW Applicator,915 MHz, 300 Watts

Implication of salt reduction on MW re-heating

• Many manufacturers review their labelling claims and recipes and reformulate their products

• Scale of changes can significantly alter the MW heating balance of their ingredients

• Salt, sugar and fat are three of the most MW reactive ingredients likely to be used in a microwaveable food product

• Salt significantly reduces microwave penetration, and salt reduction would potentially increase energy penetration depth

• MW Heating instructions may need to be validated and adjusted!

PULSED ELECTRIC FIELDS

PEF

PEF Technology• High intensity (PEF) processing involves

the application of pulses of high voltage (typically 20 - 80 kV/cm) to foods placed between 2 electrodes

• PEF treatment is conducted at ambient, sub-ambient, or slightly above ambient temperature for less than 1 s

• Energy loss due to heating of foods is minimized

• For food quality attributes, PEF technology is considered superior to traditional heat treatment of foods

• Avoids or greatly reduces the detrimental changes of the sensory and physical properties of foods

Electrical circuit for the production of exponential decay waveforms

• DC power supply

• Capacitor bank

• Charging resistor

• Discharge switch

• Treatment chamber

Square pulse generator using a pulse-forming network

• 3 capacitors

• Inductors

• Solid state switching devices

• More lethal

and effective

Treatment chambers and equipment

• 2 commercial systems available – PurePulse Technologies, Inc.

– Thomson-CSF

• Batch

• Continuous

PEF Technology in Food Preservation

• Improve the shelf-life of – bread

– milk

– orange juice

– liquid eggs

– apple juice

– fermentation properties of brewer's yeast

Microbial Inactivation

• Microbial inactivation increases with an increase in the electric field intensity– above the critical transmembrane potential

• Gram-positive are more resistant to PEF than those that are Gram-negative

• Yeasts are more sensitive to electric fields than bacteria due to their larger size

• At low electric fields they seem to be more resistant than gram-negative cells

• A comparison between the inactivation of 2 yeast spp. of different sizes showed that the field intensity needed to achieve the same inactivation level was inversely proportional to cell size

• Spores are high resistant to PEF

Microbial Inactivation Mechanism

• Electrical breakdown

(a) cell membrane with potential V'm, (b) membrane compression, (b) (c) pore formation with reversible breakdown, (d) large area of the membrane subjected to irreversible breakdown with large pores (Zimmermann, 1986)

Microbial Inactivation Mechanism

• Electroporation

Vega-Mercado, 1996b

PEF effects on enzymes

• 51.7% and 83.8% of pepsin was inactivated at 37.0 kV/cm and 41.8 kV/cm for a treatment time of 126 µs, respectively

• Activity of polyphenol oxidase (PPO) decreased 38.2% when treated at 33.6 kV/cm for 126 µs

• Activity of peroxidase and chymotrypsin decreased 18.1% and 4.0% treated at 34.9 kV/cm 34.2 kV/cm, respectively

• No significant change in lysozyme activity was observed after PEF from 0 to 38 kV/cm for 126 µs

• Enzyme inactivation was determined for lactoperoxidase in milk in comparison to thermal inactivation.

• Both PEF and the induced heat contributed to the observed inactivation effect, depending on the properties of enzymes and test conditions.

» Yang et al. Journal of Food Science, 2006, May

Plant Tissues Permeabilization

• Extractability of fruit and vegetable juices or intracellular compounds can be enhanced after a PEF-treatment – Apples, sugar beets, potatoes

• An increase of up to 7 % of yield was found in comparison to untreated samples, juice quality was equivalent

• A critical field strength of 0.3 to 0.5 kV/cm forplant and animal and 10 to 15 kV/cm for microbial cells was observed

• Meat, fruit and vegetable treatment were identified as the most promising applications to achieve a broad industrial exploitation of the PEF technique

• Energy requirements of 1 to 3 kW/t for cell disintegration and 30 to 50 kW/t for preservation

PEF Critical Factors

• Process – electric field intensity – pulse width– treatment time and temperature (50-60oC)– pulse waveshapes and polarity

• Microbial entity – type, concentration, and growth stage of microorganism

• Treatment media – pH, antimicrobials, and ionic compounds, conductivity, and medium ionic

strength– Foods with large electrical conductivities generate smaller peak electric fields

across the treatment chamber and therefore are not feasible for PEF treatment

Aspects to be considered in PEF

• Generation of high electric field intensities

• Design of chambers that impart uniform treatment to foods

• Minimum increase in temperature

• Design of electrodes that minimize the effect of electrolysis

104

Gaps in Novel Food Preservation

• Process equivalency

• Target organisms of concerns has to be determined along with the surrogates

• Detailed knowledge of microbial dose-response behavior

• Complete representation of the distribution of the lethal agent and velocity fields for development of an accurate process models

• Chemical safety

• Process uniformity

• Process monitoring, verification and validation

105

Summary

• Advances in science and engineering, progress in regulatory approvals make Novel Processing Technologies (NPT) a viable option for commercialization in foods preservation and transformation

• Preservation using NPT comprise two general categories: (1) technologies suited for pasteurizing high-acid liquid products such as HHP, PEF, US, UV and

chemical processes, including gases; (2) technologies for processing shelf-stable foods, e.g., HHP combined with temperature, MW

and RF heating, ohmic heating, and irradiation

• Regulations on Novel Foods produced by novel process differ around the world

Questions and Additional Information

• Dr. Tatiana Koutchma koutchmat@agr.gc.ca

• Thank you for you attention!