Final Flashcards
2 types of protein in milk
Casein - precipitated from solution
Whey - coagulate by heat
2 types of protein in milk
Casein - precipitated from solution
Whey - coagulate by heat
Consumer use definition of fruits and vegetables
Fruits are more sweet/used in desserts
Vegetables are more savoury
Botanical definition of fruits and vegetables
Fruits are mature plant ovaries and their seeds
Some fruits that are considered to be vegetables - tomatoes, cucumbers, avocados
True or false - In general, f&v have a high water and protein content
False. Low in protein, high water content, variable in carbohydrates
What gives broccoli it’s structure?
Cellulose and hemicellulose
Post harvest changes
Growth to maturity –> Ripening –> Senescence
Senescence
Over ripening/deterioration/programmed cell death
Two post-harvest metabolic processes
Respiration and Transpiration - management of these determines food quality
“Mature Green”
Mature but not ripe - when picked
Climacteric fruits
Fruits that will continue to ripen after harvest
e.g. bananas apples tomatoes
Why do climacteric fruits continue to ripen after picked?
Because they produce ethylene
e.g. green bananas and apples in a bag
If a banana won’t ripen?
Either chill injury or not mature when picked
Chill injury
Won’t ripen, will go straight to senescence
eg. chilled bananas
Chill injury
Won’t ripen, will go straight to senescence
eg. chilled bananas
Non climacteric fruits
Fruits that are picked when mature and will senescence after being picked.
E.g. berries (metabolize quickly), citrus (metabolize slowly)
Do not respond to ethylene
Whichever maturity the fruit is picked is where it stays
Purpose of post harvest storage methods
to manage respiration and transpiration
Controlled Atmosphere
Storage with reduces oxygen and increase carbon dioxide
e.g. refrigeration, keeping apples and bananas at low temperature and low oxygen environment
Modified Atmosphere
Packaging with reduced oxygen and added nitrogen
e.g. pre packaged veggies
What happens if oxygen levels are too low in the atmosphere?
Respiration becomes anaerobic and results in an undesirable taste and quick degradation
Grades of fresh f&v
extra fancy, fancy, commercial
Grades of processed f&v
fancy, choice, standard
True or false - there is no nutritional difference between grades
True
Canned vegetable production
grading, solubility testing, washing/peeling/cutting, blanching, inspection, can filling, addition of brine, sealing cans, thermal processing, labeling
What heat medium is added to canned f&v
Brine for vegetables
syrup/juice for fruit
Blanching
Inactivation of enzymes by controlled heating
e.g. 90 degrees for 3-4 minutes
Blanching
Inactivation of enzymes by controlled heating
e.g. 90 degrees for 3-4 minutes
What are the enzymes that are inactivated by blanching?
Polyphenol oxidase
Pectinase - breaks down pectin which hold plant cells together
Chlorophyllase
Perozidase - causes oxidative reactions
True or false - blanching is an effective thermal preservation technique
False. Destroys enzymes but does not inactivate pathogens and spoilage microbes
Polyphenol oxidase (PPO)
Browning upon exposure to oxygen
Polyphenols + O2 + PPO –> tissue browning
Good for black tea
How can PPO be inhibited?
Blanching (in processed)
Remove O2 add sulphites, decrease pH (in fresh)
Benefits of Blanching
Softens tissues
removes air from tissue
washes cut surfaces
reduces microbial load
True baby carrots vs manufactured
True - immature carrots
manufactured - cut from slender carrots, peeled and immersed in a chlorine bath
True baby carrots vs manufactured
True - immature carrots
manufactured - cut from slender carrots, peeled and immersed in a chlorine bath to destroy pathogens
Sauerkraut Production
Removal of core, outer and green leaves washed/sliced Layered with salt Fermented (by floral succession) canned
Floral Succession
Bacteria that work and build one after another
No starter culture is added
E.g. sauerkraut fermentation
Tea production
Not microbial
Green - PPO inactivated
Oolong - partial oxidation
black - oxidation (fermentation)
Black Tea production
withering leaves plucked
rollers rupture cell walls
ferment
dry
Phytochemicals
Plant chemicals with health related effects that are not essential nutrients (e.g. not macros or micros)
- act as antioxidants to stop free radical damage
Examples of phytochemicals
Lutein/Beta carotene - dark green and orange
Anthocyanins - red/purple
Lycopene - tomatoes
Polyphenols - white/cream
Hybrid f&v
Made by crossbreeding
add flavour and novelty for consumers
Three major classes of grains
Cereals - wheat, barely, corn, oat
Oilseeds - canola, soybean, flax
Pulses
2 major advantages of grain consumption
Fiber and antioxidants
Value added processing
Enhancing a product and adding value before selling it to customers
e.g. wheat to bread
Primary - milling, pearling, cleaning
Secondary - starch extraction, protein modifications
3 parts of grain cereals
Bran - fruit/seed coat
Germ - rich in protein/oil/vitamins
Endosperm - rich in starch
Starch
The main component in cereals
Composed of amylose and amylopectin
- form granules
Why is native starch not soluble in cold water?
Needs heat to loosen the molecules (gelatinization)
Amylase enzymes break down starch into sugars more easily because molecules open up when heat added
Dietary Fibre
Components of plant material in the diet which are resistant to digestion by enzymes produced by humans
3 main plant sources of dietary fibre
Cereal grains, vegetables, fruits
Hard wheat
high protein (12/14%) elastic dough i.e. bread
Soft wheat
low protein (8-10%) weak dough i.e. cakes and pastries
Durum wheat
very high protein (15-18%)
semolina
i.e. pasta
Wheat processing
Dry milled into whole grain flour, white flour, bran and germ
wet milled into starch, vital gluten and fibre
Whole wheat flour
flour, germ and bran
white flour
made from the endosperm, does not include bran and germ
Gluten protein network
produced during dough kneading and helps with dough rising, holds structure and shape
Oat processing
Dehulling into hull and groat
Heat treatment
processed into whole oat flour, bran and bran flour, oat flakes and steel cut oats
Saturated fats
No double bond
monounsaturated fats
one double bond
polyunsaturated fats
more than one double bond
Why does flax oil spoil faster than canola?
Because there are more polyunsaturated double bonds in flax oil.
The more unsaturated a fat is the more vulnerable it is to autooxidation and rancidity.
Components of grains
major >2%
minor
Pulse grains
grain legumes, high in protein
Cold extrusion
e.g. pasta dough
Hot extrusion
Crispy products, no frying or baking
Heat steam used to “puff”
Emulsifiers
Hold immiscible liquids together
Amphiphilic - has both hydrophobic and hydrophilic properties
Limiting Amino Acids
The amino acid found in the smallest quantity in a food
e.g. wheat, rice, corn high in lysine and tryptophan
How are limiting amino acids overcome?
Protein complementation
How are limiting amino acids overcome?
Protein complementation
Meat
Edible flesh from mammals and non mammals
- red, white, game, fish/seafood
True or false - the canadian meat industry is the largest sector of the food processing industry
True
What is the general proximate composition of meat products?
High water and protein content, negligible carbohydrate content
Feed conversion ratio
Measures the amount of feed eaten per unit of carcass weight gain
sheep/cattle >8
poultry 2-4
fish 1.6 - 1.8
The smaller the feed conversion ratio
the more efficient feed to meat conversion
Physical composition of meat
muscle tissue, connective tissue, and fatty (adipose) tissue
Collagen
type of connective tissue
protein structure in bone, hooves, skin etc
Elastin
type of connective tissue
holds bone and cartilage together
provides flexibility
Muscle structure of Meat
Long and thin muscle fibres
Meat muscle structure
Long and thin muscle fibres
bundles of muscle fibres
bundles of bundles
Marbling
Fat deposited within muscles
How do age and locomotion in an animal affect the toughness of the final meat cut?
They increase collagen cross linking, increasing toughness
Fish muscle structure
Short muscle fibres (myotomes) separated by large thin sheets of connective tissue (myocommata)
Some connective tissue (3%) easily converted to gelatine
Creates flakes
Postmortem biochemical processes
Lactic acid accumulation
Resolution of Rigor Mortis
Why does lactic acid accumulate in the muscle of slaughtered animals?
Because at death oxygen supply ceases, metabolism becomes anaerobic, so glycogen is converted to lactic acid (glycolysis). Lactic acid accumulates because blood is not circulating to remove it.
pH drops - not sufficient for preservation
Why does lactic acid accumulate in the muscle of slaughtered animals?
Because at death oxygen supply ceases, metabolism becomes anaerobic, so glycogen is converted to lactic acid (glycolysis). Lactic acid accumulates because blood is not circulating to remove it.
pH drops - not sufficient for preservation
Rigor Mortis
Stiffening associated with death
Without ATP generation, muscle contractions cannot be reversed
Resolution of rigor mortis
Endogenous proteases - protein degrading enzymes
Soften muscle by degrading muscle fibres
Occurs during beef aging 3-21 days
Meat Tenderisers
Protein degrading plant enzymes
Not used in fresh meat manufacturing
Beef grades
Prime (slightly abundant marbling)
AAA
AA
A
Beef Cuts
Cut according to eating quality
muscle location is associated with tenderness
sirloin, loin, ribs more tender (more supportive muscles, less connective tissue)
The most important factor for consumer acceptance of meat
Meat color
purple red - myoglobin
cherry red - oxymyoglobin
brown red - metmyoglobin
Provide some examples of “modern value-added meat products” and “traditional processed meat products”. What is the motivation behind the manufacture and development of each of these classes of products?
Modern - beef jerky, fish sticks
Traditional - Black pudding
Nose to tail
Variety
Caloric density
Provide some examples of “modern value-added meat products” and “traditional processed meat products”. What is the motivation behind the manufacture and development of each of these classes of products?
Modern - beef jerky, fish sticks
Traditional - Black pudding (barley, blood, animal fat)
Nose to tail
Variety
Caloric density
Comminuted Meat
Meat trimmings, not usually marketed as fresh, lower grade carcasses
Traditional processed meat ingredients
comminuted meat, fillers, binders
What is the curing agent used in cured meat products? What is the main reason for its use?
Sodium Nitrite
Used as an antimicrobial for Clostridium Botulinum
Results in a pink product
Hot Dog Manufacturing
comminuting, mix with spices, cure, air removed by vacuum, extrude emulsions into casings, make into links, temper at room temp, smoke, cool, package
True or false - poultry processing is more efficient than with red meat
True - resolution of rigor mortis is rapid
Why is chilling of seafood less effective?
Because they already come from a cold environment, so microbes can grow at cold temperatures
psychrophillic bacteria prevail
enzymatic reactions take place
fat may be oxidized
What is the smell of fish due to?
Trimethylamine (TMA) - an indicator of freshness
Bovine Spongiform Encepholopathy (BSE)
Progressive fatal disease of nervous system
Associated with a heat resistant prion
Cause Creutzfeldt Jakob disease in humans
Microbes in meat
E coli 0157:H7
Clostridium Botulinum
Microbes in meat
E coli 0157:H7
Clostridium Botulinum
Why is Clostridium Botulinum a concern with meat?
Vacuum packaging creates an anaerobic environment in which this bacteria will survive
Pathogens may be killed but spores are still present
Sodium nitrite added to prevent this
What are the 10 basic steps of wiener manufacture?
comminuting, mix with spices, cure, air removed by vacuum, extrude emulsions into casings, make into links, temper at room temp, smoke, cool, package
Why is refrigerated storage of fish and seafood not as effective at extending product shelf-life as it is for red meat and poultry?
Because they already come from a cold environment, so microbes can grow at cold temperatures
psychrophillic bacteria prevail
enzymatic reactions take place
fat may be oxidized
Why is Clostridium Botulinum a concern with meat?
Vacuum packaging creates an anaerobic environment in which this bacteria will survive
Pathogens may be killed but spores are still present
Sodium nitrite added to prevent this
Describe three current issues/controversies associated with meat products and their consumption.
Animal welfare and handling
Hormones and antibiotics - hormones not used in canada except with beef, antibiotics used to reduce risk of disease, especially in poultry
Fish farming vs. ocean harvesting - may be overfishing
Ante mortem inspection of an animal refers to its inspection “before death”. True or false?
True
Why is the list of ingredients on processed food products so long?
To extend shelf life
Sensory quality
Least cost (i.e. veg oil cheaper than lard)
Many ingredients to replace a single ingredient
Consistency
Food ingredients
Components of manufactured foods; often used for functionality
e.g. dried egg powder to replace real eggs
Food Additives
Chemicals added to foods at low levels to perform specialized functions; for a particular “technical effect”
Food Additives
Chemicals added to foods at low levels to perform specialized functions; for a particular “technical effect”
Does not include vitamins or minerals (food fortification) or spices/seasonings (food ingredients)
Four general functions of food additives
Facilitate processing (emulsifiers, stabilisers, thickeners, antiquating agents)
Extend shelf life and preservation (antimicrobials, antioxidants)
Improve nutritional value (vitamins/minerals)
Enhance appetitiveness and taste (flavoring/coloring substances, acid and alkalinity modifiers)
What is the name of the Canadian legislation that describes the permitted uses of food additives, including the levels and foods in which they can be used?
the Food and Drug Act and Regulations
With respect to food additives, what is the NOEL? How is it determined?
What amount of an additive can be consumed with NO effect on human health.
ADI = NOEL/100
The function of BHA (butylated hydroxyl anisole) in food products is as an antioxidant. True or false?
True
Acceptable Daily Intake (ADI)
Amount that a human can consume daily safely
Controversial Additives
MSG
Aspartame
Sulphites
Food Color
What are the two forms of protein found in milk? Which of these proteins is easily denatured by heat? Which is easily denatured by acid?
Casein and why protein
Casein is denatured by acid and whey is denatured by heat
Milk processing and Preservation unit operations
Clarification, separation, standardization, pasteurization, homogenization, vitamin fortification, packaging, ultra high temperature (UHT)
Pasteurisation
Destruction of pathogens by heat
Does not destroy all bacteria
Extends shelf life
Usually HTST
Target organism of pasteurization
Coxiella Burnetti
Vitamin Fortification in milk
Vit D to all milk
Vit A to skim and partially skim
Ultra High Temperature
commercial sterilization
135 degrees for 2-5 seconds
Agglomeration
Fine particles are moistened causing them to stick together so that it dissolves better
Concentrated milk - Why remove water from milk?
Water is highly available and easy to add, makes for a lighter products
Extends shelf life
Evaporated Milk
50% water removed, then thermal processing
Condensed Milk
50% water removed, 45% sucrose added, limited heat treatment because sugar acts as a preservative
Standard brand ice cream vs. super premium
Standard - overrun 100-120%, lower cost
Super premium - overrun 25-5-%, higher cost
Why are emulsifiers added to ice cream?
To help it hold its shape
Overrun
Amount of air added to ice cream
weight liquid - weight final / weight final x 100%
Ice cream manufacturing
ice cream mix, heat to 43 degrees, add sugar and dry ingredients, mix, pasteurization, homogenization, aging, air incorporation and freezing to -5, container filling, hardening at -34 degrees
What is the fermentation that cultured dairy products undergo?
Lactic acid fermentation
lactose –> lactic acid
Unripened dairy products
short fermentation, consumed fresh
e.g. sour cream, buttermilk, yogurt, etc.
Ripened dairy products
a second fermentation by characteristic microbes utilizes milk components to develop the characteristic attributes of the cheese
e.g. cheese
What does yogurt owe it’s structure to?
protein gel - casein proteins aggregate together to form a gel and whey protein is trapped in the gel
Yogurt manufacturing
milk preparation, addition of other ingredients, pasteurization, homogenization, starter culture addition, stirred yogurt - fruit and flavour added before packaging
What are the yogurt starter cultures?
Streptoccus Thermophilus
Lactobacillus Delbruckii
True or false - softer cheese has higher whey content
True
More whey that escapes means more protein bonding and harder cheese
Why is colour added to cheese?
Sometimes fresh grass consumption changes milk pigmentation, so colour is added to keep consistency through seasons
Cheddar Cheese manufacture
Milk preparation, starter addition, rennet addition, cutting, heating, draining (whey), curds, cheering, milling (fresh curds), salting, hooping and pressing, ripening
Ripening
The chemical and physical alteration of cheese during the curing process
What is the purpose of adding rennet to cheese?
Makes casein come out of solution and trap milk fat
What does cheese owe it’s structure to?
protein coagulation
What are probiotic bacteria?
Bacteria that help maintain the natural balance of organisms in the intestine
Failure rate for new products in the grocery store
70-80%
Types of new products
completely new (mio drops)
line extensions of current products (lays chips)
same product but repositioned (soup as an ingredient)
improvements of current products (added protein)
Who makes up the product development team?
Technology and quality
Marketing
Manufacturing
Legal Affairs
Phase 1 of product development
Product definition: Strategic plan, identify company’s current position and goal position in market, look for a hole in the market
Phase 2 of product development
Product Implementation: Prototype development, experimental design, consumer testing, prototype modifications, scale up and trial
Phase 3 of product development
Product introduction - product launch!
Support to receive feedback
When performing a market opportunity assessment using a matrix of products and their characteristics, if there is a “hole in the market” there must be a “market in the hole“. True or false?
False. May be a hole in the market for good reason.
What is the difference between ‘bench top’ versus ‘scaled-up’ plant production?
Bench top is a smaller batch for sampling
Scaled up is a larger batch with all of the processes and equipment that will be used for manufacturing.
