Food Safety - McGill University · Food safety - increasingly becoming a deep concern shared by consumers, industry and governments. Strategies – Should be directed to avoid potentially

Food Safety PAST, PRESENT & FUTURE

Professor G.S. Vijaya Raghavan

Department of Bioresource Engineering

McGill University

Canada

Global Focus on Food Safety

Risk Analysis

Interactive exchange of information and options

Key Principles of Food Safety

Prevent contaminating food with pathogens spreading from people, pets, and pests

Separate raw and cooked foods to prevent contaminating the cooked foods

Cook foods for the appropriate length of time and at the appropriate temperature to kill pathogens

Store food at the proper temperature

Use safe water and cooked materials

Elements of Farm Food Safety

Contemporary Issues

Food safety - increasingly becoming a deep concern shared by consumers, industry and governments.

Strategies – Should be directed to avoid potentially severe health hazards.

Key controversies - Genetically Modified Food

on health of future generations and genetic pollution of environment,

Can destroy natural biological diversity

Globally, food safety assurance systems - more stringent, in response to food safety problems

Food Safety Hazards

Physical

Handling Adultration

Chemical

Agricultural Production

Biological

Pathogens Toxins

Food Safety History of Canada

History

Early 1900’s

Contaminated food, milk and water caused many foodborne illnesses

Sanitary revolution

Sewage and water treatment

Hand-washing, sanitation

Pasteurization of milk- 1908

Refrigeration in homes- 1913

History

Animals identified as a source of foodborne pathogens

Improved animal care and feeding

Improved carcass processing

Surveillance and research

Outbreak investigations

Laws and policies regarding food handling

1915 –Toronto - by-law for milk pasteurization

1920 – The Food and Drugs Act

1934 – CPHA - first formal training program

in food inspection.

1938 – Ontario - compulsory

pasteurization of milk.

1942 – Canada’s first food guide

1949 – Mandatory iodinization of salt

1954 – The Food and Drugs Act - criminal law.

1972 – The first comprehensive national

nutrition survey

1997 – The Canadian Food Inspection Agency

2004 – Canadian Community Health

Survey (CCHS)

2007 –Canada’s Food Guide – Major Revision

2007 – Nutrition labelling became

mandatory

2011 - Food Expert Advisory Committee (FEAC)

Broad expert strategic advice on

regulatory and administrative oversight of foods

matters related to strategic planning, priority-setting and environmental scanning of issues related to food safety.

The Committee currently consists of 20 members

the research and academic

health and regulatory professional

Industry, patient and consumer group sectors

Current Priorities

Sodium Reduction Strategy

Managing Trans Fat Levels

Standards for acceptable limits for GM contamination

Labelling of Unpasteurized Juice and Cider Products

Global Food Safety - Timeline

700 BC – Romans – Salting and Drying

Early 1800s – Nicolas Appert - the first version

of canning

1835 James Paget and Richard Owen - pig parasite -Trichinosis

1860s Louis Pasteur - pasteurization and

fermentation

1888 – August Gärtner -Bacillus Enteritidis

1906 Appleby & Banks - irradiate particulate food in

a flowing bed

1914 - M.A. Barber -purposefully food poisoned himself

1959 - Howard E. Baumann – Pillsbury -

HACCP

1963 - Codex Alimentarius

Commission – FAO

Food Safety Timeline

The Romans - 700 BC

Salting & Drying



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


Early 1800s

First large scale canning



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1835 - Food Borne Parasite

James Paget

& Richard Owen

Pig parasite –

Trichenella Spiralis - Trichinosis



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1860s - Pasteurization

Dr. Louis Pasteur



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1888 – Food borne microscopic pathogens

Dr. August Gärtner - Bacillus Enteritidis



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1906 - Irradiation

Appleby & Banks - irradiate particulate food in a flowing bed



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1914 – Food Poisoning

Dr. M.A. Barber & 2 associates – Spoiled milk & Poisoned Themselves



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1959 - HACCP

Pillsbury



of canning



fermentation



a flowing bed



HACCP


Commission – FAO


1963 - Codex Alimentarius Commission

Food and Agricultural Organization

1980s – PEF & HPP

1993 – Biosensors

2003 - Smart Packaging – TTIs

2009 – Genomic sensors and Rapid

PCR Assays

2015 - Synthetic Bacteria

2025 - Real-Time Nanovision

2040 – Mobile apps for smartphone

cameras

2050 – Bio- Safety smart refrigerators


1980s – PEF & HPP

1993 – Biosensors



PCR Assays




cameras



1993 – Biosensors

1980s – PEF & HPP

1993 – Biosensors



PCR Assays




cameras



2003 – Smart Packaging

Safe

Unsafe

1980s – PEF & HPP

1993 – Biosensors



PCR Assays




cameras



2009 – Genomic Sensors and Rapid PCR Assays

1980s – PEF & HPP

1993 – Biosensors



PCR Assays




cameras



2015 - Synthetic bacteria

Recently an entire synthetic bacterial genome was constructed and transformed into another bacterial cell.

This is a great manipulative technology though it may take some time to master it.

In the near future commensal synthetic bacteria - introduced in the food to produce antibiotics that are detrimental to other pathogenic organisms.

Dr. Craig Ventor [Bottom Left: Synthetic Genome

transformed into Mycoplasma mycoides ]

J Craig Venter Institute, MD USA

1980s – PEF & HPP

1993 – Biosensors



PCR Assays




cameras



2025 – Real-Time Nanovision

1980s – PEF & HPP

1993 – Biosensors



PCR Assays




cameras



2040 – Mobile pathogen detection apps for Smartphones

1980s – PEF & HPP

1993 – Biosensors



PCR Assays



2040 – Mobile apps for smartphone cameras



2050 – Biosafety Refrigerators

Organisms

Estimated 250 foodborne pathogens

Foodborne illness

2 or more cases of a similar illness resulting from ingestion of a common food

Bacteria most common cause

Also viruses, parasites, natural and manufactured chemicals, and toxins from organisms

Foodborne disease outbreaks, cases and deaths in the united states

Salmonella had the highest number

Source: CDC MMWR Surveillance for Foodborne Disease Outbreaks

Microwave Pasteurization of

Shell Eggs

- A Case Study

News Update

Over half a billion eggs were recalled due to Salmonella

enteriditis contamination in the USA between the August

2010 and July 2011

Incurred a loss of nearly 300 million dollars in production

and transport costs

Sickened more than 2500 people in two weeks, leading to

additional economic losses

This strain of bacteria is found inside a chicken's ovaries,

and gets inside an egg

Eggs – Popular ingredient in many foods.

Valued for its exceptional functional and nutritional properties.

Many dishes contain raw egg as an essential ingredient.

Eggs – Potential hosts and carriers for pathogenic microbes

(Salmonella enteritidis)

The Problem

Pasteurization (57.5 C for white & 61.1 C yolk for 2.5 mins)

Present methods of In-shell pasteurization result in poor quality

eggs

Heat pasteurization with minimal changes to the egg proteins

needs consideration

Microwaves - Viable alternative for the pasteurization of In-shell

eggs

Proposed Solution Contd…

Why In-Shell?

• Mother Nature’s excellent packaging material –

the shell protects the egg

• Breaking and repacking - considerable

economic overheads

• In-Shell Pasteurization – the best possible

remedy

Need for research

Need for research

• Microwave heating is fairly non-uniform

• Heterogeneity of the egg

• Complexity in locating the points of

overheating

• Remediation of cold spots through

specific design alternatives

Contd…

Objectives – Long Term

To define the conditions under which in-shell eggs can be successfully pasteurized – microwaves at 2450MHz

To design a combination of waveguide

and egg holders (susceptors) - the required temperature profile for pasteurization inside the shell egg

Simulations using FEM Contd…


Simulations using FEM

Contd…


Temperature profile of shell egg heated in the laboratory oven with rotation - power density 2 W g-1 after 120 s

Experimental trials

Experimental trials

Contd…

Experimental trials

Contd…

Waveguide port

Focusing shield

Glass egg with egg white

Teflon turn table

Teflon stand

Applicator Design - Simulation

Simulated temperature profile

inside the egg rotating under a straight slot

(quartered)

Electric field distribution along the Z axis and the XY plane

Applicator Design - Simulation

Simulated temperature profile

inside the egg rotating under an

S-Parabolic slot

Dimension of the S-parabolic slot

Applicator Design - Schematic

Applicator Design - Setup

S-Parabolic Slotted Waveguide Applicator

Microbial Validation

CFU ml-1 of egg yolk after heat treatment using different microwave setups

Legend: CTRL – Control MWD – Domestic Microwave MWL – Laboratory Microwave MWS – S-Parabolic

Microwave

Quality Assessment - Turbidity

Shelf Life

Viscosity

Turbidity

Shelf Life- Foam Density

0.1

0.15

0.2

0.25

0.3

0.35

0 1 2 3 4 5 6 7 8 9

Foam

De

nsi

ty, g

/cc

No. of Weeks Unpasteurized MW Pasteurized Waterbath

Fisher LSD

The microwave heated egg white when compared to the

water bath heated ones

had a much higher enthalpy of denaturation

had a higher viscosity

was clearer

had a more stable foam with less foam density

had a relatively longer shelf life

The dielectric properties indicated much less

denaturation

Quality Assessment Contd…

Unsupervised k- means classified mosaic made using two eggs from each treatment

Hyperspectral Imaging

unpasteurized

Microwave pasteurized 0.75 W/g

Microwave pasteurized

1.5 W/g

Microwave pasteurized

3 W/g

Waterbath pasteurized

Reassure the safety of in-shell eggs

Help eradicate egg salmonellosis

Longer shelf life allowing transport to further distances.

Reduced breaking stock – increased profits for the

Canadian farmers

Research Outcomes

Concluding Remarks

Consumer concerns over GM food and issues like sodium reduction

Importance of regulatory interference in implementation of Food Safety

Pasteurization and sterilization

Conventional thermal processing

Non-thermal – HPP and PEF

Value addition and Nutraceuticals – Impose new challenges to food safety

Natural Sciences and Engineering Research Council of Canada

(NSERC).

Canadian International Development Agency (CIDA).

Le Fonds québécois de la recherche sur la nature et les

technologies (FQRNT).

Industry Support.

Documents

Food Safety - McGill University · Food safety - increasingly becoming a deep concern shared by consumers, industry and governments. Strategies – Should be directed to avoid potentially