Pulsed light as a novel decontamination technology for the ... inigo pp seafoodplus bilb… · Amaia Lasagabaster. 2 4th SEAFOODplus Conference 4-6 June 2007, Bilbao SUMMARY ... Microsoft

4th SEAFOODplus Conference 4-6 June 2007, Bilbao1

Pulsed light as a novel Pulsed light as a novel decontamination technology decontamination technology

for the fish sectorfor the fish sector

Iñigo Martínez de Marañón Amaia Lasagabaster


SUMMARY

■ Pulsed light process

■ Efficacy on microbial inactivation

■ Mechanisms of microbial inactivation

■ Impact of pulsed light on fish products

■ Applications in food industry (fish sector)

■ Conclusions

Pulsed light as a novel Pulsed light as a novel decontamination technology decontamination technology

for the fish sectorfor the fish sector


XENON LAMP

ENERGY(Electrical power supply)

CAPACITOR SWITCH

REFLECTORTREATMENT

CAMERA

TREATMENT

DEVICE

PULSED LIGHT PROCESS


Solar

PulsedXenon

CW Xenon

Capobianco R.A. (1998-2001). PerkinElmer Opto-electronics

LIGHT EMISSION SPECTRUM

■ Broadband light emissionspectrum (λ = 200 nm-1000nm)

■ UV region: 40 % of total light

□ UVC: 20 %

□ UVB: 8 %

□ UVA: 12 %



■ Single pulse duration: 325 µs

■ Time to reach the maximum (peak): 125 µs

■ Consecutive pulses

0

100

200

300

400

500

600

0 50 100 150 200 250 300 350 400 450 500

Time (µs)

Volta

ge (m

V)

125µs

325µs

Lasagabaster and Martínez de Marañón (2005)

TIME CONSTANTS CHARACTERISATION



High inactivation level for all of microorganisms tested (literature)

EFFICACY ON MICROBIAL INACTIVATION

BACTERIA

VIRUSES

PROTOZOAFUNGI

YEASTS

PULSEDLIGHT


High inactivation level of spoilage and pathogen bacteria isolated from fishery products:

■ Photobacterium phosphoreum■ Serratia liquefaciens■ Shewanella putrefaciens■ Brochrothix thermosphacta■ Pseudomonas Group I■ Pseudomonas Group III-IV■ Listeria monocytogenes■ Listeria innocua


SENSITIVITY-RESISTANCE OF MICROORGANISMS


For optimal microbial exposure to the light (simple solid surfaces andclear liquids):

■ Very high potential inactivation of L. innocua ( > 7 Log CFU)■ Low doses (0.35 - 1.4 J.cm-2)■ Short treatment time (< 1 s)


■ Microbial inactivation dependson LIGHT DOSE


0

1

2

3

4

5

6

7

8

9

0,0 0,3 0,6 0,9 1,2 1,5 1,8 2,1Light Dose (J.cm-2)

Inac

tivat

ion

(Log

CFU

.cm

-2)

■ The higher the microbial exposure tothe light the better the efficacy of theprocess


■ Photo-chemical effect

■ Photo-thermal effect

MECHANISMS OF MICROBIAL INACTIVATION

Combined effect


■ Photo-chemical effect

□ UV (UV-C)□ DNA and RNA damages (formation of dimers and single strand

breaks, … )□ Inability for replication No cell division Death□ Other cell components damage (proteins, cell membranes, ...)


http://www.buyaquavantage.com/images/DNA.jpg Takeshita et al. (2003)

C T


■ Photo-thermal effect

□ UV + Vis + IR □ Intense treatments□ Instantaneous cell overheating□ Cell membrane and cell wall lysis Death

Wekhof (2001)



0

1

2

3

4

5

6

7

8

9

0,0 0,3 0,6 0,9 1,2 1,5 1,8 2,1Light Dose (J.cm-2)

Inac

tivat

ion

(Log

CFU

.cm

-2)

3.811.4

2.750.7

∆Ttreatment (ºC)J.cm-2

THERMAL OR NON-THERMAL PROCESS?

■ No significant increase in temperature after pulsed lighttreatments

■ Microbial inactivation would not be due to a rise in temperature: NON-THERMAL PROCESS




■ No cooked appearance (non-thermal process)

■ No colour changes in treated fish products (CSS, desalted cod)

■ Significant reduction in Listeria spp. viability (1-1.5 Log CFU) after Pulsed Light treatment

Control Treated

IMPACT OF PULSED LIGHT ON FISH PRODUCTS

Control

Treated



Low light doses (2.1 – 4.2 J.cm-2)Short treatment time (< 1s)

Significant inactivation of Listeria spp. inoculated on the surface of fish products

Pulsed light processing could improve the safety of seafood products by reducing Listeria hazard

Significant inactivation of total aerobes mesophiles on the surface of fish products

Pulsed light processing could increase the shelf life (by taken into account microbiological criteria) of fish products

IMPACT OF PULSED LIGHT ON FISH PRODUCTS


SOLID FISH PRODUCTS■ Surface decontamination (poor penetration capability of the light)

APPLICATIONS IN FOOD INDUSTRY (FISH SECTOR)


Rough / Irregular surface■ No fissures or crevices■ Optimal decontamination

Smooth / Regular surface

FACTORS AFFECTING SURFACE DECONTAMINATION

■ With crevices which allows somehiding of microorganisms

■ Reduced decontamination

Other factors to take into account

? ?

?




LIQUID PRODUCTS■ Transparent and clear liquid products



Good penetration of light

FACTORS AFFECTING LIQUID PRODUCTS DECONTAMINATION

Optimal decontamination

Penetration of light in liquid samples depends on:

■ Colour and opacity■ Light reflection, transmission and absorption by the liquid product■ Suspended particles (microorganisms, solids …)

Poor penetration of lightReduced decontamination





PACKAGING AND PREVIOUSLY PACKED FISH PRODUCTS■ Packaging materials■ Packed fish products (optimal transmission of the light through the

packaging material)



Poor penetration of lightReduced decontamination

Good penetration of lightOptimal decontamination

FACTORS AFFECTING PACKED PRODUCTS DECONTAMINATION

Penetration of light through the package depends on:

■ Light reflection, transmission and absorption by thepackaging materials





PACKAGING AND PREVIOUSLY PACKED PRODUCTS■ Packaging materials■ Packed fish products (optimal transmission of the light through the

packaging material)

SURFACES, DEVICES AND ENVIRONMENTS■ Processing devices and instruments (e.g. seafood processing chain)■ Environments (air, water)



Rough / Irregular surface■ No fissures or crevices■ Optimal decontamination

Smooth / Regular surface

FACTORS AFFECTING PROCESSING SURFACES DECONTAMINATION

■ With crevices which allows somehiding of microorganisms

■ Reduced decontamination

Other factors to take into account:

■ Surface hydrophobicity■ Light reflection and absorption by the surface

? ?



■ Pulsed light technology is a very effective process in inactivating spoilage and pathogen microorganisms (vegetative bacteria, bacterial and fungal spores, viruses, …)

■ This high efficacy against microorganisms would be achieved after a very short treatment time and low light dose

■ Pulsed light could be used to decontaminate the surface of solidproducts (e.g. packed or unpacked seafood products), clear liquids, processing surfaces and devices (e.g. seafood processing chain) or packaging materials

■ Pulsed light processing could improve the safety (Listeria hazard) and increase the shelf life of fish products (by taken into account microbiological criteria)

CONCLUSIONS


or combined with other treatments (HURDLETECH project):

CONCLUSIONS

■ Effect of Pulsed Light Technology on physico-chemical and sensorial characteristics of fishery products

RESEARCH CONTINUES…

■ Pulsed light could be used alone

□ Chitosan□ Protective cultures (LAB)

PL

HURDLE

pHaw T PLHURDLE TECHNOLOGY


CONCLUSIONS

■ Demonstration project

□ 4 industries

□ Different seafood products

□ Different problems to solve in each industry (target microorganisms, surface cross-contamination, product quality, processing chain, packaging phase, …)

□ For each product/industry, specific trials will be carried out to estimate the optimal treatment conditions (light dose, treatmenttime, …) and select where the pulsed light technology must be inserted in the processing line

WORK CONTINUES…


This work was performed within the Integrated Project (IP) SEAFOODplus and partially granted by:

EU Commission (FOOD-CT-2004-506359)

Department of Agriculture, Fisheriesand Food from the Basque Government

Spanish Ministry of Education andScience (FIT-060000-2004-285)

ACKNOWLEDGMENTS

Iñigo Martínez de Marañón and Amaia [email protected] [email protected]


A better life with seafood…

www.seafoodplus.org

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Pulsed light as a novel decontamination technology for the ... inigo pp seafoodplus bilb… · Amaia Lasagabaster. 2 4th SEAFOODplus Conference 4-6 June 2007, Bilbao SUMMARY ... Microsoft