process control the key to meeting microbiological ... · the key to meeting microbiological...

Process control The key to meeting

microbiological specifications?

Christine Robertson and Sam RogersJay Kocharunchitt and Bianca Porteus

Mandeep Kaur and Tom RossJessica TanIan Jenson

We start with a sterile carcase under the hide and we add contamination

Cattle hot carcase Chilled carcase

Food Safety

Objective (FSO)

Food Safety

Objective (FSO)

Food Safety

Objective (FSO)

Primal /Trim

Hide removalSpillageTools and equipmentHands

Chiller airGrowth during chilling

Tools and equipmentsurfaces

What are our performance objectives?

• Meeting MHA

• Meeting the RI

• Meeting ESAM windows

• Not detecting E. coli O157 in 375g of N-60 samples

• Getting vacuum packed product primals to distant markets within spec

We start with a sterile carcase under the hide

Sum of Contamination from various places (increases)

Sum of treatment to remove contamination(removal)

The performanceObjective

+ - ≤

In-plant investigations

Many plants do investigations –

about 30 of them are summarised

Example of some decreases -- steam vac of brisket

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Boxplot for TVC Before Vac

0 1 2 3 4 5

Boxplot for TVC After Rinse

Example of some decreases -- Twin Oxide, hide and carcase

Treatment

E. c

oli (

log 1

0 cfu

/cm

2 )

-1

0

1

2

3

Without TO With TO

Hide on

Without TO With TO

Hide off

Today’s session1 Process control – what we put on and what we take off during dressing and chilling – a case study

Christine Robertson, JBS DinmoreSam Rogers, SARDI

2 The Holy Grail – chilling as an interventionJay Kocharunchitt, UTas Food Safety Centre

Bianca Porteus, UTas Food Safety Centre3 A new software tool for predicting shelf life of vacuum packed primals

Mandeep Kaur, UTas Food Safety CentreTom Ross, UTas Food Safety Centre

4 ESAM: Getting the most out of your micro testing program

Jessica Tan, SARDI

Process control – what we put on and what we take off during dressing and

chilling – a case study

Christine Robertson, JBS DinmoreSam Rogers, SARDI

Process control

JBS Australia – EST 235 – Dinmore QLD

Est 235 Profile• Beef establishment – Slaughter, Carcase Chilling,

Boning, Packing, Carton Freezing / Chilling.• Employ approximately 2000 workers• Two shift operations (10 hours per shift) 5 days• Slaughter chain speed – 213 head per hour• Slaughtering target approximately 3500 head per

day. (1750 per shift)

Animal Welfare / Cattle Handling

• Cattle handling is conducted with specific controls in place through to the ante mortem pens then onto the knocking box.

• 100% of cattle are washed• Flappers are the preferred method in aiding movement

of animals in the race.

Slaughtering and Dressing Process

• All animals are presented for Halal slaughter.• Stunning equipment is a pneumatic mushroom

stunner (Halal eligible) or captive bolt (non-Halal status)

• Animals must have the throat cut within 30 seconds from stunning from a certified Muslim slaughterman.

• Traceability procedures are in place – NLIS tag scanned, carcase allocated a body number and lot number to link with the vendor.

Dressing• We plug the oesophagus prior to

Halal slaughter and clip the at neck opening.

• Carcase Dressing is conducted through individual steps to reduce the risk of contamination from the hide.

Dressing

We have 3 downward hide pullersWe have X Government authorised officers doing post-mortem inspection

MHA and micro monitoring

• We do all the usual MHA inspections and AusMeatgrading

• We test carcases before the decontamination cabinet by excision sampling twice/shift at four high-risk sites – Bung, Loin, Brisket & Neck.

• Samples are tested for E. coli, Coliforms & TVC.

• This is to support the Dinmore HACCP plan and to alert potential risks with microbiological contamination that could lead to increased risk of E. coli O157:H7 / STEC positive results.

Intervention – decontamination cabinet Our decontamination cabinet (APV) was validated by

Food Science Australia with a 2 log reduction.

Sides are treated with flumes of hot water (deliverytemperature ranging from 83°C to 91°C) forapproximately 15 seconds.

We recycle water through a two-tank system and ismaintained within the specified operating parameters(max turbidity 200NTU).

Hot potable water is added continuously to make-upwater. When the turbidity is reached it will switch tothe other tank – ongoing).

Decontamination cabinet

Carcase entry

Carcase exit

Carcase Chilling

Town water used for spray chilling – no chlorine added and is not chilled.

Key – aggressive chilling at the front of the regime, 100% fan speed, 0°C temp for approximately 4 hours

We spray chilling to prevent shrink.

Case study

We know a lot about what we put on the carcase at important sites – as well as the ESAM sites

We wanted to know more about what we take off in the APV

And about how the micro is after we’ve spray chilled

So we ran a PIP

Case studyKey elements of the PIP were:

1. Sample shift 1 for one week (5 days) each month for 3 months

2. Excise surface tissue at four sites: butt, loin, brisket, neck

3. Sample before APV, after APV, after overnight chilling

4. Test for TVC and E. coli

5. SARDI processed and analysed the data

Case studyKey finding 1: TVC concentrations

Before pasteurisation:• Most samples above limit of detection (10 cfu/g)• Bung - highest, Neck – lowest concentrations

After pasteurisation:• Most samples less than L.o.D.• Up to 2 log average reductions

After chilling:• No significant growth on Bung (<0.5 log)• >1 log growth on Neck• Loin and brisket somewhere in between

Case study

Key finding 2: Top-down redistribution of TVC

Pre APV Post APV Post Chilling

80

25

15

15

2

3

7

4

3

10

25

45

52,500

16,000

1,000

900

How well does it cope?

<10

<10

<10

<10

APV

Usually pretty well…

<10

10

<10

10

How well does it cope?

500

1,100

6,000

320

APV

There were some exceptions… but only in 7% of samples

21%

1% 1%

4%3%

0% 0% 0% 0% 0% 0% 0%0

5

10

15

Pre APV Post APV Post chillingProcess location

E. c

oli d

etec

tions

(

10 c

fu/g

)

Site

Bung

Loin

Brisket

Neck

Case study

Key finding 3: Effective against E. coli

Next time?

An LOD of <10 misses a lot.If we do anything similar in future there are two improvements to tell us about low concentrations:

• We can lower the LoD to 5 cfu/g by making a 5x dilution in the Whirlpak bag

• We can enrich the Whirlpak bag by incubating it overnight which would tell us if we have:

– A count of 1-4 cfu/g– No E. coli at all

Outcomes1. Unfortunately ESAM doesn’t show much relationship

with STEC findings

2. And doesn’t tell us what’s happening in our process at the high-risk sites

3. Our in-house excision sampling prior to the APV alerts the teams to risks in each day’s processes –that points us to corrective actions

OutcomesWe know now:• The reductions the APV delivers at high-risk sites• What carcase handling and spray chilling allows back

on

There’s lots for us to think about having done this work, for example:

• Chilling the carcase quickly for the body temperature to be reduced to ˂7°C then allow the carcases to dry

• Thinking about weekends / long weekends if bodies are not dry

• Keep focusing on process improvement• Extending our in-house excision testing to post-APV

Process control The Holy Grail – chilling as an intervention

Jay Kocharunchitt, UTas Food Safety CentreBianca Porteus, UTas Food Safety Centre

• Australian meat industry/MLA since 1990’s

• Developed tools, which are routinely usedRefrigeration IndexEHECs in fermented meatsShelf life/spoilage of VP meats

• Predictive microbiology/risk assessment, also expert panels

University of Tasmania

• Can model in test tubes and on meat

• Can change the conditions to simulate industrial settings

• Can do ‘modern microbiology’

University of Tasmania

Meat Safety

• Pathogenic Escherichia coli such as O157:H7, O111, O26 etc.

• A biggest problem– poses a serious threat to public

health– have a big impact on economy

• More stringent requirement for E. colion meat

– In USA, ‘Zero Tolerance’ policy for seven serotypes

• Many interventions being employed such as– hide wash,– knife trimming, – hot water wash, – acid wash etc.

• No single treatment completely effective– not 100% assurance of safe, wholesome meat – need for an effective and low cost intervention

And…

• Has the potential to be developed as effective intervention

• Based on previous knowledge,• chilling leads to a lowering of bacterial counts on

the carcases• counts are always “higher” on hot-boned

carcases compared with chilled carcases

• Attractive • would be a no-cost intervention,• would be easy, so everyone

would be using it

Chilling Process

• Develop intervention(s) against E. coli for Australian meat industry Effective Reliable Cost-effective

Ultimate Aim

• E. coli shows a complex pattern of behaviour during exposure to weekend chilling.

• Numbers drop then come back EVEN THOUGH GROWTH IS NOT POSSIBLE

E. coli Growth during Chilling

1. Conditions still allow growth.2. Dramatic changes in temperature and desiccation level

cause injury of E. coli cells.3. E. coli then gradually recover from injury, although growth is

not possible during this period.

So What’s Happening?

1 2 3

• E. coli switched on and off several genes in response to the chilling conditions

Molecular data

A model for E. coli response

Molecular Study

E. coli cells during air chilling

Particularly, E. coli initially became more susceptible to oxidative damage during the chilling process

Injury Recovery

Oxidative stress

response

Molecular Study

• We understand how E. coli behave during air chilling

• We now know that E. coli become more susceptible to oxidative stress

• Application of oxidising agent has the potential and may be used as part of the chilling process

Key Messages

• Chlorine Dioxide (ClO2)– Good oxidising agent– Accepted by international markets– Relatively cost-effective– Easy to use– ≤ 200ppm acceptable level

• Air chilling conditions• Spray chilling conditions

Application of Oxidant

• Meat-based broth– similar properties to meat – e.g. pH

• Spray chilling– Temperature gradient water bath

set to chill – from 35C to 7C

• ClO2 applied at different time points

• Monitoring changes in E. coli numbers over time

Application during Chilling

• E. coli response under spray chilling conditions with addition of 100ppm chlorine dioxide

Results

Results

• E. coli response under spray chilling conditions with addition of 100ppm chlorine dioxide

• Potential intervention during both spray and air chilling

• > 5 log reduction of E. coli with chlorine dioxide at much less than acceptable level

• Timing of application is critical

Key Messages

• Mini-scale chiller sets up to simulate abattoir chilling temperature profiles and air circulation

Meat Trials

• Oxidation of E. coli occurs with ClO2

• Significant log reduction in pathogenic E. coli

• ClO2 is easy to set up and use

• Plan to move to on site chiller at JBS Longford abattoir Larger scale trials on carcases Chillers modified for the addition of

ClO2 to existing spray infrastructure

Summary

• University of TasmaniaTom RossLyndal MellefontJohn BowmanMandeep KaurMichelle Williams

• JBS Longford abattoirPhil Robertson

• MLAJohn SumnerIan JensonLong Huynh

Thank You

Tom RossMandeep Kaur

Power failure – what do we do now?

A new software tool for predicting shelf life of vacuum packed primals

Shelf life

“The length of time that a commodity may be stored without becoming unfit for use

or consumption”

Shelf life ends because of:

Spoilage – microbial growth produces off odours, flavours

Chemical changes – fat breakdown in frozen meat

Colour defects – browning, greening

Food safety – presence of a pathogen, a declared adulterant

Shelf life of Australian vacuum packaged (VP) primals

Early work by CSIRO in the 1980s -- pre-requisites for optimizing shelf life:

• Low initial counts <log 2-3 cfu/cm2

• Packaging film with low oxygen permeability• Good control of temperature throughout storage

and transportation

Given the above industry could expect:

• VP beef primals 70-84 days• VP lamb primals 42-56 days

Latest work Indicates:

• VP beef primals up to 200 days• VP lamb primals >85 days

Shelf life of Australian vacuum packaged (VP) primals

The bacterial communities which enable a long shelf life

Initial microflora, a mix of Gram -ve spoilers like Pseudomonas which are biochemically active and break down protein to amines

Gas atmosphere (20% CO2, very low O2) prevents growth of pseudomonads and favoursLactic Acid Bacteria (LAB)

Microflora gradually changes until LAB reach 107 - 108/cm2

A snap shot of relative abundance of bacterial communities developing in VP lamb shoulder stored at -1°C

Why count on counts?

Import requirements of various countries

Importing countries set shelf life regulations in two ways:

Arbitrary shelf lifee.g. boneless meat has 49-day shelf life, which must enter Egypt no ˃24 days from the date of slaughterpresents logistical difficulties

Micro based shelf life e.g. Aerobic Plate Count of n=5, c=3, m=106 and M=107 for chilled meat into the Gulf statesdifficult because a count of 107 is normal and desirable

Supermarket specifications

Major supermarkets have some total counts specifications which are impossible to achieve:

Retailer A: VP primals <5,000,000/gRetailer B: Minced meat <1,000,000/gRetailer D: VP lamb <5,000,000/g at end of shelf life

Other retailers are more realistic.Retailer C: Beef cuts <10,000,000/g at end of shelf lifeRetailer E: <500,000/g at point of entry to their processing facility

Shelf life of Australian vacuum packaged (VP) primals

Early work by CSIRO in the 1980s re pre-requisites for optimizing shelf life:

• Low initial counts <log 2-3 cfu/cm2

• Packaging film with low oxygen permeability• Good control of temperature throughout the

storage and transportation periods

Blowing during airfreight

High temperature after shipping – but for how long has it been there?

What you need to know:

• How fast spoilage microbes grow at different temperatures

• Temperature and time for the rest of the cold chain• Total Count at packing

What you need to know:

• How fast spoilage microbes grow at different temperatures

••

UTas working on tools to predict the shelf life of VP primals at different temperatures

Storage location & temperature (°C)Longford (commercial temp)

UTas 8.3°C

UTas 4°C

UTas 2°C

UTas working on tools which predict the shelf life of VP primals

UTas working on tools to predict the shelf life of VP primals

Predictive tools for meat microbiology

UTas working on tools to predict the shelf life of VP primals from storage temperature records

What you need to know:

•

• Temperature and time for the rest of the cold chain•

Temperature data loggers

What you need to know:

•

•• Total Count at packing

How can you use the tool?

1. Assist in identifying where the temperature went wrong

during shipping

2. Help you and your customer decide if the lot is still

acceptable

3. Help you decide whether the lot should be diverted to

another market, e.g. after freezing

4. Other?

Example 1: Shipping VP lamb to Europe – storage at -0.7°C for 50 days

Example 2: Shipping VP lamb to Europe – storage at +0.5C for 30 days and +1°C for 20 days

Process control ESAM: Getting the most out of your micro

testing program

Jessica Tan, SARDI

Background of ESAM

• Micro testing at establishments did not begin until mid 1990s• Jack-in-the-Box outbreaks in USA

• AQIS brought in the ESAM (E. coli and Salmonella Monitoring) program in 1998

• Testing for E. coli O157:H7 started soon after• Testing for ‘Big 6’ STECs from June 2012

At the time, testing was for market access and practically no use was made of the data from ESAM or O157 testing.

What more can ESAM data be used for?

ESAM Data

• Establishment ID• Species• Date of Sample/Testing• Carcase vs Carton • Dressing• Hot vs Cold Swabbing• Shift/Chain

• Total Viable counts (TVC)• Coliform

counts/prevalence• E. coli (generic)

counts/prevalence• Salmonella prevalence• Salmonella serotype

• E. coli O157:H7prevalence

• ‘Big 6’ STEC “prevalence”

ESAM and SARDI

• Started monthly reports in 2009• National and establishment reports• ESAM and E. coli O157• Hot Swabbing reports• Anonymous comparison

Investigation 1

Limit of Detection

LOD: Technicalities

TVC LOD for Beef

0.08 cfu/cm2 => -1.10 log10 cfu/cm2

TVC LOD for Sheep

0.33 cfu/cm2 => -0.48 log10 cfu/cm2

LOD: The Good, the Improved and the Not So Good

The Good

LOD: The Good, the Improved and the Not So Good

The Improved

LOD: The Good, the Improved and the Not So Good

The Not So Good

Investigation 2

Carcase vs Carton

Carton vs Carcase: combined

Carton vs Carcase: individual

Carton vs Carcase: individual

Investigation 3

Spray Chilling

Spray Chilling

Does spray chilling adversely affect microbiological results?

Spray Chilling

0.88 log10 cfu/cm2 1.03 log10 cfu/cm2

Spray Chilling

4.6% 5.4%

ESAM and the future

ESAM Reports• Carton results• “Big 6” STEC reporting

Take Home Message:

Utilise ESAM Data with all its potential.

Questions and wrap-up

Ian Jenson

Processors' guide to improving microbiological quality

About 30 experiments are summarised in this guide

Shelf life of Australian red meatWe think the manual will be an invaluable resource for technical, marketing and regulatory members of our industry.

Email Long at lhuynh@mla.com.au with your:NameAddressNumber of copiesReason for the book