Chapter 1 and 2 Flashcards
What is food science
- Nature and composition of food materials and their behavior
- Interdisciplinary science to study the nature of foods, the causes of their deterioration and the principles underlying food processing
-The treatment of food substances to preserve them and improve their quality or make then functionally more useful
What do food processors do
Take raw animal. edible vegetables , or marine materials and transform them into edible products through the application of labor, machinery, energy , ad scientific knowledge
The purpose of food processing and the reason
The reason- biological nature-> deterioration,
Purpose: to preserve food, to extend the edible period
Traditional methods of preserving foods
- Drying
- Salting
- Smoking
- Fermentation
What do we believe the food was like before?
More nutritious , but in fact it was poor even for more well off
What people ate before
Rare meat ( only when killed and slaughtered) -Veg and fruits only in some places
-Heavily relied on staple foods as wheat, potatoes, because it is easy to store. Still 90% of intake
Who invented canning and when
1810 Nicolas Appert
Jars were hermetically sealed by boiling, did randomly
How was invention of Appert helpful
For Napoleon and his wars
When jars became widespread
After invention of cane opener in 1855
What happened in 1859
Invention of ammonia compression-> first refrigerator all -year round
What is the safer option for ammonia and when was it invented
1920s
Chlorofluorocarbons (CFCs)
Low toxicity, low reactivity, low flammability-> can be placed at home
What happened in 1867
Louis Paster- bacteria are a cause of food borne disease -> pasteurization
What did Clarence Birdseye do and when
Technology for quick freezing of foods developed in 1930s “A father of the prozen food industry “
What is the central concern in food nowadays?
Food safety: microbiological contamination
Consumers are involved in ___
maintaining the safety of food
In what institutions food science is required
- Canada Food Inspection Agency
- Health Canada
- Us Food and Drug Administration
- WHO
- FAO
Four pillars of food security
- Food availability
- Food access
- Food utilization
- Food system stability:
Food science professional societies
Canadian Institute of Food Science and Technology
-Institute of Food Technologists
-Internatioanl Union of Food science and Technology
-American Oil Chemists’ Society
-American Association of Cereal Chemists
AOAC
Why AOAC is important for us
Methods that have legal standing
If some kind of test is needed for nutritional labeling, here is the first place to look
What is the contribution of food sector in canada’s economy
- 5 billion dollars- 6.7% of GDP
16. 7% of labor work in industry
How many food/beverage establishements are there in canada
9000 ( more than 50% in Ontario or Quebec)
Export / import of food in Canada
Export: 43.6 billion, fifth larger, 3.5 % of world agriculture and exports
48,4 % of export foes to US , 11,4 % to china
Imports: 32,2 billion, 6th larger importer. 61,2 & are from US
How many food businesses in Quebec and how many people does it employ
1500 businesses 70,000 workers
Where most employment is concentrated
Montreal metropolitan
What are the size of food companies in quebec an dhow much the employ
80% have fewer than 50 employees
4,5% have more than 250
The larger company provide 43,5% of all jobs
Key products in Quebec
- Milk
- Other dairy products
- Meat
- Baked goods and confectionery
- Fruits and vegetables
- Fruit juices
- Soft drinks
- Animal food
- Beer, sprits and wine
What type of business is common in Quebec
Cooperatives, especially in dairy, meat, animal food and maple product
What is Agropur, how many farms, how much product a year
Largest dairy cooperative in Canada
More than
3300 farms
More than 3 billion liters of milk a year
More than 3 billion sales a year
How much people spend on food in Canada and US
10%
What is Food Freedom Day
1st week of February, by this date the average Canadian has earned enough money to pay for the food for the entire year
Why in some countries people spend 50-100% of income on food , but in canada only 10?
- Differences in income
- Differences in food costs
Major contributing factors in different food cost
- Advanced agricultural practices
- Advanced food preservation and processing technologies
- Very efficient distribution networks
How many people the farm could fed and feeds now
1940-12
2006-200
Is there more small farms or large farms?
Small-62%, but only 7& of the value
Large- 5%, but value of 49%
Who owns large farms
Majority- family-owned
A few- corporations
Downside of agricultural production efficiency
- Monocultural practices-> pests-> extensive use of pesticides
- Extensive use of fertilizers
- Environmental issues
What are post-harvest losses in the developing world and why
More than 50%
Because of pests (birds, insects, etc.)
No refrigeration
Little preservation technology
Four sectors of the food industry
- Production
- Processing
- Distribution
- Marketing
Describe production sector
Primarily farming and fishing
Involves variety selection, cultivation, harvest and some bulk pre-processing and storage (slaughter, controlled atmosphere, refrigeration/freezing)
What is controlled atmosphere
CO2 concentration is increased, so less O2 for oxidation , more storage time
All processing requires
Quality control and must satisfy legal regulatory requirements
How can you process milk
- Milk ( different %)
- Cheeses
- Ice creams
- Yogurts
- Condensed milk
- Powdered milk
- Butter
- Etc.
What does distribution sector include
Wholesale, retail and food service operations
How many retail outlets are in Canada
24,000
What i happening with competition in retail
Very competetive, because limited shelf-space and low-margin. that is why there is is sales to get rid of product for the new
Internet and food retail
The only retail sector where it is not used, only 0,3% of food sales
How do retailers keep everything organized
-Computerization and scanners
What are allied industries and their examples
Support industries
- Packaging
- Specialty chemicals/functional ingredients
- Equipment
Companies need to be highly responsive to
Competition ans demographic changes, trends/forces
- Politics
- Government regulations
- health/environment issue
Key demographic changes affecting the food industry
- Aging population
- More women in work force
- More ethnic diversity
- Changes in disposable income
- Higher levels of education
- More nutritional/medical awareness
- Smaller household size
What is the issue with product development
- Essential in remaining competitive
- Expensive process
- But new products fail 95% of the time
What are steps in scientific method of product development
-Ask questions
-Define problem
-Conduct research ( maybe somebody did something like that and failed, etc.)
-State hypothesis, possible solutions (test you hypothesis repeatedly yo have a theory)
-Design an experiment (should be variable and a control)
Conduct experiment (record data-numerical and descriptive)
-Evaluate the results
-Report the results ( conclusion analysis)
Each change in an experiment is a ___
Variation
Who can be involved in scientific research and what should be done with conflicting information
Medical experts may be involved
Make a meta-analysis for controversial data
What is happening to the world’s population and economy
Population is constantly rising, but economy is not growing as expected
How many people are still hungry today?
820 million
What is happening with the number of hunger people
The prevalence of undernourishment has stabilized by the absolute number is increasing
How many people in the world are experiencing moderate or severe food insecurity
2 billion
Where and in what population there is a concentration of moderate or severe food insecurity
Concentrated in low-and middle-income countries, but also 8% in Europe and North America
Higher in women than men
What are 2030 SDG and 2025 World Health Assembly goals and are we meeting them
Sustainable Development Goals- half the number of stunted children
2025-reduce the prevalence of low birthweight by 30%
One in seven babies are born with low birthweight
How many people die because of obesity related issues in the world
4 million per year
What is another way to monitor hunger and what is happening with its value
Food insecurity experience scale
Number is slowly rising
Where hunger is on rise and at what percentage
In almost all subregions of Africa -20%
Slowly rising in Latin America and the Caribbean, but still under 7%
What part of Asia is the most susceptible to undernourishment
11% of the overall population
South Asia, improving, but still at 15%
What are experiencing people that are under the category moderately food insecure
Lack regular access to nutritious and sufficient food -> greater risk for malnutrition and poor health
The indicator for hunger
Undernourishment +FIES
How many people in (%) are severely insecure and moderate
Severe -9,2% of the population
17,2%- moderate
Countries with higher prevalence of moderate or severe food insecurity tend to have ____
Higher rates of adult obesity
In upper-middle and high-income countries, living in food insecure countries is a predictor of ___
obesity in school-age children, adolescents and adults
What is sensory evaluation
The analysis of the taste, smell, sound, feel , and appearance of food
Describe how physical factors can influence food likes and dislikes
Body chemistry
Number of taste buds
Age
Gender affect the ability to detect flavors
What is taste bias
A like or dislike that is linked to past negative or positive experiences
What else is a contributor to psychological bias apart from taste bias
Label terms Brand names Advertising Peers Setting
Name two other factors (apart from psychological and physical) that influence food likes and dislikes
Cultural- Beliefs and behaviors ->exposures to food-> food preferences
Environmental->people are more likely to eat what is available and economical; immediate surrounding
Appearance refers to ___ and is measured by
The shape, size, condition, and color of a product
Colorimeter- the color of foods in terms of hue, value, and chroma
What is used in order to avoid the influence of light on a taste panel
Colored lights
Flavor is the combined effect of
Taste and aroma
6 tastes
Bitter Salty Sour Savory Sweet Umame
Foods as lemons, tea, and sourballs are evaluated in terms of
Astringency
What is the odor of food
Aroma
What might affect the flavor of food
Temperature
Odor results from
Volatile particles coming in contact with the olfactory bulb
Texture is
How food product feels to the fingers, tongue, teeth, and palate
5 textures
Chewiness Graininess Brittleness Firmness Consistency
The ability to slide without breaking. What is it?
Chewiness
The thinness or thickness is
consistency
What is the size of the particles
graininess
Food’s resistance to pressure ____
Firmness
How easily a food breaks apart
Brittleness
What is a taste pane;
Evaluates food flavor, texture, appearance,and aroma’ performed by trained specialists
What is consumer test panels
Help to determine products the average consumer will prefer; performed with untrained;
Compare a new product to one on the market; evaluate new types of products
What factors can influence on panelists during panels
Influence form other testers- prevent seeing facial expression, need to remain quiet during the evaluation
Environmental factors- light levels in testing room are the same, tests take place in a room separate from the food preparation room, testers sip water between each sample to prevent lingering and do not swallow afterwards
All product are served at room temperature
Psychological bias: only 3 digit random code, and only 4 to 5 products can be judged at a time
How evaluation van be performed
Numerical scoring
Verbal label
Universal form (images)
What is food chemistry
The branch of food science that deals with the chemical composition of foods, the physiochemical (physical and chemical) properties of food components, the physiochemical changes that occur in foods during handling, processing ,and storage, and the chemical basis of functional properties of food ingredients
pH and food preservation
Knowing the pH environment in which bacteria grow best is crucial to preserve food and keeping it safe
Where do botulism bacteria grow, yeasts and molds (ph)
Botulism - above 4.6
Yeasts 4.0-7.0
Molds- 2.0-8.5
How pH influence food color
Acids( lemon, cream of tartar)- develop white color
Chocolate cakes have a deeper, darker color and smoother flavor if the batter is basic
What happens with eggs during storage
Eggs become more basic as CO2 escapes through the egg shell ( you need fresh eggs for cooking, because it will have more air)
What is functional property
The contributions that individual ingredients make the characteristics of food products (structure and texture, flavor, appearance, shelf life)
What is functional food
Any food or food ingredient that may provide a health benefit beyond the nutritional value of the nutrients it contains ( probiotoc yogurt, cereals with added fiber
What is nutraceuticals
Any naturally derived bioactive compounds that are found in foods, dietary supplements, or herbal products and have health promoting, disease-preventing, or medical properties
How dietary supplements and functional foods are sold
Typically sold in capsules, tablets, or other pharmaceutical-type formats while functional foods are sold as foods/beverages
Elements that are present naturally
Hydrogen Boron Carbon Nitrogen Oxygen Fluorine Sodium Magnesium Alumnimum Silicon Phosphorus Sulfur Chlorine Potassium Ca V Cr Mn Fe Co Ni Cu Zn As Se Br Mo I
Key minor components and what roles they have
Minerals Vitamins Acids Pigments Flavors Additives
Nutritional, aesthetic, functional
Major food components
CHO
Proteins
Lipids
Water
Oligosaccharide- how many carbons
3-10
Examples of polysaccharide
Starches
Cellulose/ hemi
Pectins
Gums
The result of connection of 2 AAs , how many molecules of water
1
The simplest sugar
Glucose
What happens to sugars when dissolved in water
The cyclic structure-> unbound,hydroxyl group becomes carbonyl functional group (ketone and aldehyde)
Sugars are active only in
Open-chain form , because of carbonyl functional group that becomes functionally active, but cyclize very quickly
Two main types of sugars
Aldoses
Ketoses
The bons that connects two simple sugars
Glycosidic ( like an ether bond R-O-R)
Maltose is found in
Used to make beer
Formation of disaccaride will result in
1 water
Oligosaccharide are poorly
Digested in upper GI, they are food for microflora
Bacterial metabolism of oligosaccharides produces
Organic acids and gases
Substances that have a good effect on the growth of bacteria
Prebiotic
The benefits of probiotics and prebiotics are
Speculative ( not clinically proven)
How many people in the world are dying from obesity
4 million
D vs L in sugars
Last OH group should be on the left from the projection->L, on the right ->D
How sugars cycle
Aldehyde or ketose group react with last OH group
Percentage of molecules in the open-chain form at any moment
1%
Alpha vs beta glycosidic bond
If the bond lie in one plain->alpha
In different-> beta
Oligosaccharides are present in
In many fruits, vegetables, and plants
Organic acids form bacterial metabolism of oligosaccharides are the only
Source of calories form ingestible oligosaccharides
Two groups of oligosacharides
Fructo-oligosaccharides
Galacto-oligosaccharides
FO and GOS have been found to
To favor the growth of “good” bacteria over “bad”
The most common polysaccharide in food is
Starch
Where starch is found, size and solubility
Starch is found in water-insoluble granules in the endosperm of wheat, corn,etc. Granule size varies by factor of 50, ranging from 2microm(rice) to 100 microm(potato)
Granules are made of
Amylose and Amylopectin
Length of amylose and characteristics
alpha-d-glucose
250-300 units
Branches in amylopectin occur every
15-25 units
How many glucose units are found usually in starch
The order of 1,000
Proportion of amylose and amylopectin depend on
Plant source
If starch is insoluble in water, how can use it
When heated in the presence of water, hydrogen bonds between branches are disrupted, starch undergoes gelatinization to from a gel( a three-dimensional network), because granules start to absorb water and swell
The process of gelatinization is used
For thickening and texture modification of the product
What happens to starch in cold water
Suspension is formed
What happens at gelatinization temperature and above it
Increased viscosity( formation of paste)
Above->granules swell more and viscosity continue to increase and some starch molecules( particularly amylose) start to leach in the the water. If continued to heat-> viscosity begins to decrease, because more starch escapes granules which will rupture eventually
What happens with gelatinized starch when it is cooled
If the starch concentration is sufficiently high, the starch chains re-associate to reform hydrogen bonds in an ordered structure, trapping water inside->formation of a gel
What is a key contributor to the texture of freshly baked bread
Wheat starch gelatinization
Retrogradation happens when… and its example
Starch gels may become firmer due to continued formation of hydrogen bonds between starch chains
Staling of bread->retrogradation example
What is syneresis
Freeze/Thaw cycles when water is forces out of the gel->appearance of water droplets in the surface of a thawed pie
What changes affect gelatinization behavior and tendency for retrogradation
Size of starch granules Amylose/amylopectin ratio Average length of amylose and amylopectin chains
The more there is the content of amylopectin, ___ temperature of gelatinizatio
Higher the temperature of gelatinization
In addition to its important functional roles as thickening and gelling
agents in a wide variety of products, starch is extensively used as a _____
raw material for the production of syrups and sugars . E.g. high fructose syrup (HFS).
What does different names like HFCS 55, HFCS 45 mean
there are designated by the percentage of glucose that has
been converted to fructose
The higher the number, the sweeter the product
Cellulose is
Cellulose is a structural polysaccharide in plants and one of the most
common molecules in the biosphere.
Why we are unable to digest cellulose
We do not have an enzyme for breakage of beta-glucose bond
Cellulose is composed of
alpha-D-glucose, amylose
As we cannot break the bond in cellulose, how can we use it
derived food additives can provide
useful functional properties without adding calories or affecting
taste.
How MCC is produced
Microcrystalline cellulose (MCC) is a food additive that is produced by partial depolymerization of cellulose.
12 functional roles of MCC
Anti caking agent and flavor carrier in grated and shredded cheese
Stabilizes foams
Stabilizes emulsions
Replaces fats and oils, is used in low fat hot dogs, reduced fat ice cream
Forms gels, improves adhesion (cling) of sauces, salad dressings
Modify texture thickens with favorable mouth feel
Improves quality of low solids tomato sauces
Freeze thaw stability, retards ice crystal growth
Suspending agent in ice cream
Vegetable fat whipped toppings improves body, texture, stability
Other food uses: Barbecue sauces, frozen cheese lasagna, frozen
guacamole, marshmallow topping, liquid diet products, sandwich spreads,
low calorie mayonnaise
Tabletting agent
CMC is
Carboxymethylcellulose (CMC) is a chemically modified cellulose:
some CH 2 OH groups are replaced by CH 2 COOH groups to increase
solubility in water.
How CMC is used
CMC is used to increase viscosity without adding calories.
CMC forms weak gels that trap water.
CMC is used in ice cream to improve texture, prevent drip and retard
formation of ice crystals during frozen storage.
Vegetable gum is
“Vegetable gum” polysaccharides are substances derived from various
shrubs or trees.
Properties of vegetable gum
thickeners,
stabilizers, or gelling agents in various food products.
4 examples of vegetable gums
guar gum: gum Arabic gum karaya gum tragacanth
Guar gum is extensively used to
guar gum: improves the consistency of gluten free baked goods
Where pectins are found and what they are used for
Pectins are found in plant cells and made of sugar acids a key
component in jams and jellies
Pectins substitute gelatine in vegan products
Other name for indigestible fiber
is called fiber, bran, or bulk on food labels
Indigestible fiber role in human body
aids in digestion and the elimination of waste
helps maintain a feeling of fullness
Use of indigestible fiber in food products
is added to commercial bread products to slow staling and improve loaf
volume
6 key functional properties of sugar
(1) Have sweetening power (2) Are fermentable (3) Agents for flavor and color production (caramelization/Maillard (4) Contribute mouthfeel ( (5) Preservatives (6) Tenderizers
How sugar helps in preservation
Water is attracted to sugars , but to a solution-. no water available for microorganisms
Why many foods are sweetened with sugar
The sensation of sweetness generally elicits a favorable response
Evaluation of sweetness is very ___
Subjective
What is the rank of sweetness in sugars
sweetness: fructose > sucrose > glucose > lactose
2 other alternative sweetening agents and their relative sweetness
Xylitol-sugar alcohol -90
Aspartame-non-carbohydrate artificial sweetener-20000
How the sweetness of sucrose can be varied
The glycosidic bond in sucrose is readily hydrolyzed by heat or acid,
How the variability of sweetness of sucrose can be avoided
This variability can be avoided by converting sucrose to invert sugar ,
e.g., to stabilize its sweetness in acidic beverages such as soft drinks.
Involves use of an enzyme (invertase) that catalyzes the splitting of
sucrose into an equimolar mixture of glucose and fructose.
Fermentation is
Fermentation involves conversion of sugars to alcohols and carbon
dioxide or organic acids by microorganisms (yeasts and/or bacteria).
How fermentation can preserve the product
Acids and alcohols produced by fermentation act as preservatives by
inhibiting the growth of other microorganisms.
When does caramelization reactions happen
Caramelization reactions occur when any concentrated sugar solution
is heated (e.g., maple
Heating results in breakdown of the sugar molecules and
polymerization of the breakdown products.
Caramelization reactions are used commercially to produce
(a) flavor caramel syrup
(b) caramel color, e.g., cola drinks
What is the most important reaction in food chemistry
Maillard reaction
What is happening during Maillard reaction
Involves the reaction of the open chain form of sugars with primary
amine ( RNH 2 ) groups , present in amino acids and
What is the result of maillard reaction and in what products it happens
Color and flavor produced numerous volatile flavor compounds are
formed and many of the aromas we associate with specific foods are due
to this reaction:
Coffee flavor, color and aroma formed during roasting
Popcorn aroma/flavor
Roasted peanuts
Baked bread aroma
Viscosity of sugar solutions increases with increasing ____
Sugar concentration
What is the issue with diet soft drinks and how it is solved
Diet soft drinks are sweetened with very low amounts of artificial
sweeteners and would not have the same mouthfeel; sugar alcohols
may be added to increase viscosity.
What is the most effective way to keep freshness of baked goods
invert sugar
How sugars act as tenderizers
Sugar changes the viscosity or pourability of doughs and batters because
sugar interferes with flour s ability to form an elastic structure
