Food Science
What it’s all about!
Food Science
What is food science?
• Food science is the study of the chemistry,
physics and biology of food.
• Food technology is the application of knowledge
and principles learned from food science to food
processing, preservation, distribution and
evaluation.
Statistics
Mathematics
Engineering
Chemistry
Food Science
Physics
Microbiology
Biochemistry
Molecular Biology
Common Misconceptions About
What Food Science Is
Food Preparation
• Trained as a chef, or cook,
more of an art than a science
Nutrition
• Nutritionists try to determine
how much and what foods we
should eat. Food scientists use
this information to design the
food products and processes.
Jobs in Food Science
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Product Development
Quality Assurance
Safety Control and Inspection
Research (academia or industry)
Safety or Quality Testing
People will always eat so there will always
be jobs in Food Science!!!
Main Areas
• Biology
• Food Safety
• Food Microbiology
• Chemistry
• Food Chemistry
• Food Analysis
• Physics
• Food Processing
• Food Packaging
Biology
Food Safety
Food Microbiology
Food Microbiology
• The study of bacteria,
viruses, yeast and
moulds and how they
affect food and
consumption
• Both adverse and
beneficial effects:
Spoilage and illness vs.
fermentation and
probiotics
Adverse Microbes
• Food
Spoilage
• Illness
- Changes in texture, colour,
taste, or odour during storage.
- E.g. Mouldy bread.
- Intoxication or infection
caused by microbes or their
secretions.
- E.g., botulinum toxin or e-coli
infection
Beneficial Microbes
• Fermentation
• Probiotics
- Bacteria and yeast ferment
carbohydrates in food, this
results in alcohol, acid, and
gas
- E.g. Yeast make alcohol in
beer and wine, bacteria make
acid in yogurt
- Bacteria that are beneficial to
health are incorporated into
food products
- E.g. Bifidus or Casei bacteria
are added to yogurt after
fermentation
Current Microbiology Research
• Bacteria left on
spinach leaf after
washing
Bacteria
• Shows bacteria
trapped within leaf
contours
Food Safety
• Quality and Safety control to make
sure food provided to the consumer
is free from contamination by:
– microorganisms
– foreign bodies
– dangerous chemicals
Food Pathogens
www.textbookofbacteriology.net
Todar's Online Textbook of Bacteriology
• Microrganisms that cause food borne
infection or intoxication:
E.coli
Salmonella
Listeria
Campylobacter
Botulinum
Staphylococci
Foreign Bodies
• Any non-edible materials such as:
– Glass: No glass is allowed on the production floor of a
food manufacturing plant
– Plastic: All plastics containing food ingredients are
coloured (usually blue or green) to make them easy to
see
– Metal: Metal detectors are mandatory at the end of all
production lines to ensure no metal contaminants in
the food
– Insect parts: microscopy, inspection
Dangerous Chemicals
• Any chemical agent that can cause
adverse, short or long term, health effects:
– Cleaning chemicals
– Packaging materials
– Dangerous additives
– Natural toxins
Food Chemistry
Food Chemistry
Food Analysis
Food Chemistry
• Foods consist mainly of proteins,
carbohydrates, and lipids
• Functionality: any property other than
nutritional characteristics that contribute to
an ingredient’s usefulness in food products
Food Chemistry
Major Functionalities of Proteins:
1) Gelation – proteins interlock and trap water to
form a gel Eg. Jello
2) Emulsification – allows for the mixing of oils
and water Eg. Egg protein in salad dressing
3) Foaming – Proteins form a network that traps
air Eg. Whipped egg meringue
4) Fibre Forming – Simulates meat texture Eg.
Soy burgers
Food Chemistry
Major Functionalities of Carbohydrates:
1) Sweeteners – Small chain carbohydrates used
as sweetening agents Eg. Sucrose
2) Preservatives – Sugars reduce the availability
of water, thus reducing microbial growth Eg.
Jam
3) Fermentation – Used by microbes as a food
substrate Eg. Yeast in beer produces alcohol
4) Gelation – Long chains of sugars connect and
trap water to form gels Eg. Alginate in olive
pimentos
Food Chemistry
Major Functionalities of Lipids:
1) Crystalization – Fats crystalize in
different ways to give different food
textures Eg. Chocolate, ice cream
2) Emulsifiers – Fats like monoglycerides
act as emulsifiers
3) Taste – lipids act as flavour carriers,
affecting the taste sensation and
mouthfeel
Current Food Chemistry Research
• Microfiltration to separate milk proteins
• Changing Ice Cream Crystallization
• Analysis of Whey proteins and comparison
after different heat treatments
Food Analysis
• Principles and techniques for quantitative and
qualitative analysis of food composition, sensory
properties and safety
• Breaking food down into components:
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Water
Crude Fat
Crude Protein
Crude Fibre
Nitrogen Free (Starch, Sugar)
Ash (Minerals)
Food Analysis
Scenario
Cheese making:
Microbiology – Lactic Acid Bacteria
Safety – Listeria, Salmonella, E. Coli O157
Chemistry and physics – Casein Gelation
Analysis – Nutritional Labels
Processing – Gelation, Cutting, Syneresis, Healing,
Cooking, Draining, Moulding, Aging
Packaging – Vacuum Packing, Appealing Design
Physics
Physical properties of food
Food Engineering and Processing
Food Packaging
Physical and Physico-chemical
Properties of Foods
• Colours
• Colligative properties; freezing point,
vapour pressure, water activity
• Food dispersions (dispersed particles)
such as emulsions
• Formation of gels
• Food texture and rheology: hardness,
elasticity, compressability etc
Food Engineering
• Mass balances; when you make apple
juice, where do all the apple components
go?
• Energy balances; how can I pasteurize
beer with less energy?
• Separation systems; can I use a
membrane to remove bacteria from beer,
so I don’t have to pasteurize it?
Food Processing
• Methods and technology used to transform
agricultural products into food products
• These processes include:
– Pasteurization
– Drying
– Canning
– Filtration
– Freezing
Pasteurization
• The elimination of
pathogenic bacteria and
reduction in numbers of
spoilage bacteria.
• Ensures a safe product
and extends shelf life
• Often used during
production of:
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Milk
Honey
Beer
Juices
Drying
• The dehydration of foods
• Removing 95%-99% of water from a
product by means of various process
• Processes include:
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Tunnel Drying – vegetables, fruits
Drum Drying – potato flakes
Spray Drying – coffee
Freeze Drying – drinks, instant meals
Canning
• The process of sealing a food in an airtight
container and destroying all
microorganisms by heating
• The sterilization temperature is dependant
on pH:
pH
Temperature
4.6 or greater
> 121°C
4.5 or lower
< 100°C
Filtration
• Separation of parts of a product by
size
• Used to:
– Extract certain ingredients
– Remove unwanted particles
– Remove microorganisms
• Processes include:
– Cross Flow Filtration – Milk
– Reverse Osmosis – Water Treatment
– Charged Carbon Filtration - Brita
Freezing
• The lowering of a products temperature
to below approx -10°C
• Decreases rates of chemical change
and stops growth and metabolism of
microorganisms
• Processes include:
– Blast Freezing – packaged foods
– Fluidized Bed Freezing– Individual Quick
Frozen Products
– Immersion Freezing – Juices
– Scraped Surface Freezing – Ice Cream
Food Packaging
Types of Packages
• MAP – modified atmosphere packages
used to store contents in a gas other than
air
• Biodegradable – packages that will
decompose over a relatively short amount
of time in a landfill
• Recyclable – materials that can be
recycled
• Permeable – Packages that allow the
permeation of air, moisture, or both
Packaging Research
• PLA instead of PET – biodegradable
plastic like pop bottles
• Modified Atmosphere Packaging
• Edible Packaging
Other Resources
• The Science Behind Our Food, U of
Georgia, Detailed lesson plans on food
science for high schools,
www.uga.edu/discover/sbof/
• Food Science Ambassador program, Can
Inst of Food Science and
Technolwww.cifst.ca/default.asp?id=1027
• Institute of Food Technology Teacher
Resources,
http://members.ift.org/IFT/Education/TeacherResources/
Acknowledgements
• This presentation is based on a slides prepared
by undergraduate students, Ben Chan and
Michelle Wong, University of Guelph.
• The brochure on food science was prepared by
undergraduate student Sara Wong.
• The CIFST Ambassador program is directed by
the Scientific and Public Affairs Committee of the
Canadian Institute of Food Science and
Technology. For more information contact Art
Hill, arhill@uoguelph.ca