valerio giacconce school of veterinary medicine – university of padua (italy) natural casings and...
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Valerio GiacconceValerio GiacconceSchool of Veterinary Medicine – University of Padua (Italy)School of Veterinary Medicine – University of Padua (Italy)
Natural casingsNatural casingsand food safety:and food safety:an up-to-datean up-to-date
Who I amWho I am
My name is Valerio GiacconeMy name is Valerio Giaccone
Full professor of “Meat HygieneFull professor of “Meat Hygieneand Food Inspection”and Food Inspection”
Who I amWho I am
My Collegues sayMy Collegues sayI am …I am …
… … the “Food detective”the “Food detective”
Who I amWho I am
I I would like to be called would like to be called ……
… … the “Food Doctor”the “Food Doctor”
As Doctor …As Doctor …
… … I I should make everythingshould make everythingto keep the food “safe” to keep the food “safe” ……
… … and keep awayand keep awayevery possible “every possible “hazardhazard” ”
ArgumentsArguments
What we know on casingsWhat we know on casings
What we should betterWhat we should betterunderstandunderstand
What we should discoverWhat we should discover
WhatWhatwe know onwe know onnatural casings?natural casings?
We know that …We know that …
… … natural casings arenatural casings areworldwide used as “skin” …worldwide used as “skin” …
… … for various kind of sausagesfor various kind of sausagesand other foodsand other foods
We know that …We know that …
… … the commercial trade ofthe commercial trade ofnatural casings on the world …natural casings on the world …
… … plays a considerableplays a considerableeconomic roleeconomic role
Houben (2005)Houben (2005)
““In 2002 the total EU foreignIn 2002 the total EU foreigntrade in natural casings …trade in natural casings …
… … was about 1.4 billion dollars”was about 1.4 billion dollars”
Koolmees (2004)Koolmees (2004)
He reports that the tradeHe reports that the tradeof natural casings …of natural casings …
… … is estimated in 2is estimated in 2.5 billion.5 billiondollars per yeardollars per year
We know that …We know that …
… … the 60% of natural casingsthe 60% of natural casingsused for sausages …used for sausages …
… … comes from the smallcomes from the smallintestine of sheepintestine of sheep
Natural casings …Natural casings …
… … are drawn from theare drawn from thesubmucosa of animal gut …submucosa of animal gut …
… … by desliming and strippingby desliming and strippingoff their mucous and muscularoff their mucous and muscularlayerslayers
Natural casings …Natural casings …
… … are usually preparedare usually preparedby salting, curing and drying …by salting, curing and drying …
… … various part of animal gutvarious part of animal gut
HazardsHazardsfor human healthfor human health
FirstFirstHAZARD and RISK …HAZARD and RISK …
… … ARE NOT THE SAME THINGARE NOT THE SAME THING
An hazard …An hazard …
… … is a physical, chemicalis a physical, chemicalor biological agent …or biological agent …
… … which can be dangerouswhich can be dangerousfor human healthfor human health
An hazard …An hazard …
… … is always an hazard …is always an hazard …
… … aside from the foodaside from the food
For exampleFor example
Ice cream contains a lot of airIce cream contains a lot of air(and of Oxygen)(and of Oxygen)
Clostridium botulinumClostridium botulinum grows growsonly in strict anaerobiosisonly in strict anaerobiosis
For exampleFor example
Clostridium botulinumClostridium botulinumis an hazard for ice cream ?is an hazard for ice cream ?
YES, because itYES, because itcan cause botulism in humanscan cause botulism in humans
Nevertheless …Nevertheless …… … the probabilitythe probabilitythat that C. botulinum C. botulinum growsgrowsin ice cream …in ice cream …
… … is very low, because the is very low, because the presence of too much oxygenpresence of too much oxygen
The riskThe riskA risk isA risk isthe mathematicalthe mathematicalprobability …probability …
… … that an hazard can occurrthat an hazard can occurr
Kind ofKind ofhazardhazard
Chemical residuesChemical residues
Microbial pathogensMicrobial pathogens
MicrobialMicrobialhazardshazards
VirusesViruses
BacteriaBacteria
ToxigenicToxigenicmouldsmoulds
ChemicalChemicalhazardshazards
XenobioticXenobioticcontaminantscontaminants
NaturalNaturalcontaminantscontaminants
Microbial pathogenMicrobial pathogen
Salmonella entericaSalmonella enterica
CampylobacterCampylobacter
Listeria monocytogenesListeria monocytogenes
Escherichia coliEscherichia coli VTEC VTEC
Chemical residuesChemical residues
Heavy metalsHeavy metals
Antibiotics & chemoterapicsAntibiotics & chemoterapics
PesticidesPesticides
Mycotoxins (ochratoxin)Mycotoxins (ochratoxin)
Microbial pathogenMicrobial pathogen
In 2009 in European UnionIn 2009 in European Unionoccurred more than …occurred more than …
… … 190.000 cases of human190.000 cases of humanfoodborne campylobacteriosisfoodborne campylobacteriosis
Microbial pathogenMicrobial pathogen
In 2009 in European UnionIn 2009 in European Unionoccurred more than …occurred more than …
… … 108.000 cases of human108.000 cases of humanfoodborne salmonellosisfoodborne salmonellosis
Microbial pathogenMicrobial pathogen
In 2009 in European UnionIn 2009 in European Unionoccurred …occurred …
… … 1.645 cases of foodborne1.645 cases of foodbornehuman listeriosishuman listeriosis
Foodborne diseases 2009Foodborne diseases 2009
The EU Summary ReportThe EU Summary Report““Trends and Sources of ZoonosesTrends and Sources of Zoonosesand Zoonotic Agents andand Zoonotic Agents andFood-borne Outbreaks in 2009”Food-borne Outbreaks in 2009”
What we knowWhat we know
Natural casings are notNatural casings are nota substantial source …a substantial source …
… … of foodborne pathogensof foodborne pathogensfor sausagesfor sausages
As consequenceAs consequenceNatural casings areNatural casings aremicrobiologicallymicrobiologicallyfully acceptable …fully acceptable …
… … if they are adequatelyif they are adequatelydry-salteddry-salted
What we knowWhat we knowVery rarely natural casingsVery rarely natural casingsharbor harbor SalmonellaSalmonella, …, …
… … Listeria monocytogenesListeria monocytogenesor other microbial pathogensor other microbial pathogens
Why ?Why ?Because their productionBecause their productionprocess and …process and …
… … because the antimicrobialbecause the antimicrobialaction of salting and curingaction of salting and curing
The pathogensThe pathogens
They are normally harboredThey are normally harboredin gut of animals, so they …in gut of animals, so they …
… … could pass to natural casingcould pass to natural casingin the first production stepsin the first production steps
But … …But … …… … by salting, curing and dryingby salting, curing and dryingthe gut for the gut for at least 30 daysat least 30 days … …
… … it is very rare thatit is very rare thatSalmonellaeSalmonellae and other and otherpathogens can survivepathogens can survive
ClostridiaClostridiaSulphite-reducing Sulphite-reducing ClostridiumClostridiumare sometimes detectedare sometimes detectedin natural casingsin natural casings
They produce high resistantThey produce high resistant““spores” which survive in salt spores” which survive in salt
BacillusBacillus
The same risk can occorrThe same risk can occorrwith spores of with spores of Bacillus cereusBacillus cereus … …
… … another causeanother causeof foodborne intoxicationof foodborne intoxication
Nevertheless …Nevertheless …
… … the risk for sausages …the risk for sausages …
… … comes from the alivecomes from the aliveclostridia, NOT from sporesclostridia, NOT from spores
We know that …We know that …
… … the alive the alive ClostridiaClostridia CAN NOT CAN NOTgrow in natural casings …grow in natural casings …
… … because their salt contentbecause their salt content
An experienceAn experienceof challenge testof challenge test
Aim of the studyAim of the study
Inspired by Bailocom, we haveInspired by Bailocom, we haveperformed a challenge test …performed a challenge test …
… … to study the behaviourto study the behaviourof of ClostridiaClostridia in natural casing in natural casing
The numbersThe numbers
We have analysed 120 samplesWe have analysed 120 samplesof natural casings …of natural casings …
… … looking for the chargelooking for the chargeof sulphite-reducing of sulphite-reducing ClostridiumClostridium
The numbersThe numbersThe 30 casing in whichThe 30 casing in whichwe found the most high chargeswe found the most high chargesof of ClostridiumClostridium … …
… … were then used to producewere then used to produceraw seasoned sausagesraw seasoned sausages
The testsThe tests
21 sausages at the begin21 sausages at the beginof seasoning and other …of seasoning and other …
… … 21 sausages at the end21 sausages at the endof seasoning were analysed of seasoning were analysed
The resultsThe results
In all samples tested we haveIn all samples tested we havefound charges of found charges of ClostridiumClostridium … …
… … always below 10 cfu/g of meatalways below 10 cfu/g of meat
What does it means?What does it means?
Natural casing can contain lowNatural casing can contain lowcharges of charges of ClostridiumClostridium spores … spores …
… … but the spores have no realbut the spores have no realsignificance for the sausagesignificance for the sausage
What we shouldWhat we shouldbetter understandbetter understand
VirusesViruses
Certain viruses, pathogenic forCertain viruses, pathogenic forbreeding animals, may persist …breeding animals, may persist …
… … in adequately salted casingsin adequately salted casings
VirusesViruses
Cattle and sheep’s gut canCattle and sheep’s gut canharbor infectious viruses …harbor infectious viruses …
… … of Foot and Mouth diseaseof Foot and Mouth disease
VirusesViruses
Pig gut can harborPig gut can harborinfectious viruses of …infectious viruses of …
… … Classical Swine Pest VirusClassical Swine Pest Virus(Hog cholera virus)(Hog cholera virus)
It is possible …It is possible …
… … to treat natural casingsto treat natural casingswith anti-viral compoundswith anti-viral compounds
These treatments can inactivateThese treatments can inactivatethe pathogenic virusesthe pathogenic viruses
TreatmentsTreatments
They are based on They are based on lactic acidlactic acidor citric acid …or citric acid …
… … and also on orthophosphatesand also on orthophosphates
EffectivenessEffectiveness
At today it seems that theseAt today it seems that thesetreatments are effective …treatments are effective …
… … to inactivateto inactivatepathogenic viruses, but …pathogenic viruses, but …
… … but …but …
… … we must take high carewe must take high careto the to the rinsing of casingsrinsing of casings … …
… … after the treatmentafter the treatment
The rinsingThe rinsing
It is probable thatIt is probable thata rinsing of only 3 hours …a rinsing of only 3 hours …
… … it is not sufficient to washit is not sufficient to washaway all residues of additives away all residues of additives
Instead …Instead …
… … a rinsing of 16 hoursa rinsing of 16 hoursseems to be sufficient …seems to be sufficient …
… … to wash away all residuesto wash away all residuesof acid or basic additives of acid or basic additives
TSE riskTSE risk
In bovine and sheep gut couldIn bovine and sheep gut couldbe present prions of …be present prions of …
… … transmissible spongiformetransmissible spongiformeencephalopathies (BSE/scrapie)encephalopathies (BSE/scrapie)
TSE riskTSE risk
In the EU no casings areIn the EU no casings aremade from native-born cattle made from native-born cattle ……
… … because cattle intestine isbecause cattle intestine isa specified risk material (SRM)a specified risk material (SRM)
TSE riskTSE risk
Natural casings derived fromNatural casings derived fromsheep and goats can harbor .sheep and goats can harbor .……
… … the causative agent of scrapiethe causative agent of scrapie
We know that …We know that …
… … most TSE infectivity residesmost TSE infectivity residesin the mucosa …in the mucosa …
… … particularly in the particularly in the lymphoidlymphoidnodules (s.c. Peyer’s patches)nodules (s.c. Peyer’s patches)
LLymphoid nodule (Peyer’s patch)ymphoid nodule (Peyer’s patch)
Natural casingsNatural casings
Because the Because the severe processsevere processof desliming and stripping …of desliming and stripping …
… … they ARE NOT particularlythey ARE NOT particularlyat risk to harbor TSE prionsat risk to harbor TSE prions
What we shouldWhat we shoulddiscover ondiscover onnatural casings?natural casings?
Chemical residuesChemical residues
They are a real “black hole” They are a real “black hole”
There is a quite completeThere is a quite completelack of scientifica datalack of scientifica data
Chemical residuesChemical residues
Pharmacological treatmentsPharmacological treatmentsare regularly performed …are regularly performed …
… … in reared animalsin reared animals(antibiotics, chemotherapics …)(antibiotics, chemotherapics …)
Chemical residuesChemical residues
Other chemical residues can beOther chemical residues can bepresent in gut content …present in gut content …
… … because they come from feedbecause they come from feedand environment (heavy metals)and environment (heavy metals)
In theory …In theory …
… … residues of all theseresidues of all thesecontaminants could be present …contaminants could be present …
… … also in natural casingsalso in natural casings
In literatureIn literature
We have only a report aboutWe have only a report aboutthe persistance of residues …the persistance of residues …
… … in natural casingsin natural casings
At today …At today …
… … we DO NOT have scientificwe DO NOT have scientificdata about the real amount …data about the real amount …
… … of antibiotics, heavy metalsof antibiotics, heavy metalsand/or pesticides in casingsand/or pesticides in casings
Personally …Personally …
… … in this last month I beganin this last month I beganto perform some analysis …to perform some analysis …
… … looking for heavy metals andlooking for heavy metals andochratoxins in natural casingsochratoxins in natural casings
I hope …I hope …
… … You will substain my effort …You will substain my effort …
… … to obtains sufficientto obtains sufficientscientific data in this researchscientific data in this research
In conclusionIn conclusionRemember that … Remember that … … … an hazard is always an hazardan hazard is always an hazard
What is important is the RISK,What is important is the RISK,i.e. the probability of an hazardi.e. the probability of an hazard
In conclusionIn conclusionIt is quite probable that naturalIt is quite probable that naturalcasing are products …casing are products …
… … with a very low riskwith a very low riskfor human health, but …for human health, but …
… … but …but …
… … it needs to demonstrateit needs to demonstratethis low risk …this low risk …
… … from a scientific point of viewfrom a scientific point of view
… … forfor
Your attention!
Your attention!