Predictive Microbiology for Spices and Herbs

1 June 2016 I Stratakou, HWM den Besten and MH Zwietering

Food Safety

Objective(FSO)

Appropriate Level Of Protection

(ALOP)

ALOP & FSO

Model for Spices and Herbs

Consumers

Harvest

DecontaminationStorage

Process steps 

Log N (c

fu/g)

ICMSFH0- ΣR+ΣI < FSO

Food Safety Objective-FSO

Η0

ΣR ΣI=ΣG+ΣC

FSO

Zwietering, 2005

ΣI~0

FSO

ALOP

ReductionInitiallevels

Own Meta-analysis

Existing databases

Experiments

Prevalence/levels

Own Meta-analysis

Existing databases

Experiments

Parameters (±PIs)

Dose/Response

Consumption

Mortality rates

ALOP & FSO

Deterministic

95% percentile

StochasticInactivation/

Tenacity

Foodborne Diseases in Spices

Salmonella spp. in powder paprika● Other agent/matrices

ALOP: 1 death per year per 108 people● 128 illnesses per year per 108 people

Salmonella spp. FSO=-5.4 log cfu/g

FSO-5.4 log cfu/g

Log

N (

cfu/

g)

FSO Factors-H0

Prevalence of Salmonella spp. in spices● EU data: RASFF & EFSA data=0.03● Published studies: not only EU=0.05

● WHO data: global (& EU) data=0.03

H0=-3 log cfu/g Batch of oregano tested, absence of salmonellas

Η0-3FSO=-5.4

Log

N (

cfu/

g)

FSO Factors-ΣRInactivation

ΣRInact=ΣRThermal /ΣRIrradiation

Η0=-3

Log

N (

cfu/

g)

FSO=-5.4

Other meta-analyses

Experimental findings

Irradiation

‐9

‐8

‐7

‐6

‐5

‐4

‐3

‐2

‐1

00 5 10 15 20 25

Survival (log

 cfu/g)

Dose (kGy)

Spores

Cells sporeformers

Cells non‐sporeformers

N= 71  D10=4.3(PI±2.1)  

N=77    D10=3.2(PI±2)

N=111   D10=1.8(PI±3.1)

Irradiation

‐9

‐8

‐7

‐6

‐5

‐4

‐3

‐2

‐1

00 5 10 15 20 25

Survival (log

 cfu/g)

Dose (kGy)

Cells non‐sporeformersN=111   D10=1.8(PI±3.1) 

Irradiation

‐9

‐8

‐7

‐6

‐5

‐4

‐3

‐2

‐1

00 5 10 15 20 25

Survival (log

 cfu/g)

Dose (kGy)

Cells non‐sporeformers

S.Infantis N=30  D10=1.3

N=111   D10=1.8(PI±3.1) 

1.8

0.7

1.3

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Cells non-sporeformers

D1

0 (

kGy)

Spices

van Gerwen et al, 1999

S. Infantis

FSO Factors-ΣRInactivation

ΣRInact=ΣRIrradiation

Inactivation Factors: Spores & Gram stain● Dirrad value spores: 4.3(PI±2.1) kGy

● Dirrad value vegetative: 1.8(PI±3.1) kGy

Irradiation of paprika: 10 kGy-5.5 log cfu/g

ΣR-8.5 log cfu/g

Η0=-3

Log

N (

cfu/

g) FSO=-5.4

FSO Factors-ΣRtenacity

ΣRtenacity Survival in storage conditions

FSO=-5.4

Own meta-analysis

Tenacity studies

-3

Log

N (

cfu/

g)

-8.5

Survival

0.0

1.0

2.0

3.0

4.0

5.0

0 10 20 30 40 50

Log D (lo

g days)

T (0C)

Gram pos(spores)

Gram neg(veg)N=126  D=2.9 (PI±0.7)

N=38  D=2.2 (PI±1.3)

Survival

0.0

1.0

2.0

3.0

4.0

5.0

0 10 20 30 40 50

Log D (lo

g days)

T (0C)

Gram neg(veg)N=38  D=2.2 (PI±1.3)

Survival

0.0

1.0

2.0

3.0

4.0

5.0

0 10 20 30 40 50

Log D (log days)

T (0C)

Gram neg(veg)

    InfantisS.Log D=2

N=38  D=2.2 (PI±1.3)

FSO Factors-ΣRtenacity

ΣRtenacity Survival in storage conditions

Tenacity Factors: Spores, Gram stain● Log Dsurv spores: 2.9(PI±0.7) log days=2.3 years

● Log Dsurv vegetative: 2.2(PI±1.3) log days=0.5 years

20 0C, 0.46 aw Storage of paprika: 1 year~-2 log cfu/g

ΣR≈-10.5 log cfu/gLog

N (

cfu/

g) FSO=-5.4-3

-8.5

Salmonella spp. in Paprika Powder

FSO

Log

N (

cfu/

g) -3

-5.1

-8.5

-5.1

-2.1

-10.5

0.4

-7.1

Conclusions

Framework for quantification of control in the spice/herbchain

Determined the effect of variability factors

Scenario analysis

Acknowledgments

Jen Banach Tom Kim Dongmin Emi Amalia Budri Gerrald de Vries Ilias Apostolakos FUCHS

Thank you for your attention

Questions?

21

ALOP-FSO

Mortality rate Salmonella=0.78%Ill=death/mortality rate=1/0.0078=128

Ill p.p/p.d.=r*Dose=r*average consumption*concentrationR=0.0075Ill p.y/population=ill*365*108

Average consumption=weight*portions=1.8/16=0.11gConcentration=10^FSOFSO=log(ill/r*avcon*365*108)=log(128/0.11*365*108)=-5.4 log cfu/g

22

Factors

Levels = prevalence of 0.03 equals to 3 positive (1 cfupresent) in 100 samples, if 25g per sample then 3cfu/2500g=0.0012=-3log cfu/g

Irradiation=-0.55*10=-5.5 log cfu/g

Storage= 2.39-0.0055*20=2.28 Log D D=190 days 1 log reduction for 365 days=1.92 log cfu/g reduction

23

Thermal

‐2.5

‐1.5

‐0.5

0.5

1.5

2.5

65 85 105 125

Log D (log

 min)

T (°C)

Bacillus cereus