Unit 2 Flashcards
What are the 4 methods of increasing food productivity
Agricultural chemicals
Aquaculture
Irrigation
Biotechnology
Plants and animals modified by genetic engineering are called _____
Transgenic
What is the difference between the outcome of genetic engineering vs traditional breeding?
In genetic engineering, only the desired gene is transferred whereas in traditional breeding, other genes may be transferred
3 pros of food biotechnology
Minimize food shortages
Reduce environmental impact
Improve nutritional health
What is organic farming
Farming without the use of certain pesticides, fertilizers, antibiotic growth hormones, and GMOs
What are some farming practices that promote sustainability
Crop rotation Covering crops (prevent soil erosion) Using renewable resources Enhancing biodiversity Compost for soil fertility Balancing host/predator relationships
True or false: scientific evidence strongly supports that organic food is much healthier than normal food
False
A product must contain at least ___% organic ingredients to be certified organic
95%
What is food processing
Conversion of raw plant and animal tissue into convenient and practical forms for consumption
What are six methods of Food processing
Moisture removal Heat treatment Low temperature treatment Acidity control Traditional non-thermal processing Non-thermal processing innovations
What is moisture removal
Removing biologically active water in an attempt to stop microorganism growth (drying, dehydration)
What is heat treatment
Pasteurization, blanching, canning, baking, cooking, sterilization
What is low Temperature treatment
Cold storage (fridge, freezer)
What is acidity control
Controlling the pH of the food
What is traditional nonthermal processing
Chemical additives or food packaging
What is nonthermal processing innovations
Irradiation, high pressure
What are food processing aids
Specific food additives like gums, natural colouring agents, enzymes and sweeteners
What is food preservation
Do use of specific processing techniques to reduce spoilage, microorganisms in food and to improve safety and shelf life
What is one of the primary causes of food spoilage
Biologically active water in tissues
What are the 3 classes of food preservation
Chemical
Biological
Physical
Salt and other preservatives such as _____ reduce water activity in foods
Potassium sorbate
What are preservatives
Additives that maintain the freshness of foods
What is fermentation
A biological method of preservation that involves bacteria or yeast acting on the carbs of a food.
Lowers the pH, resulting in taste changes
What is the oldest form of food preservation
Drying
___ needs 15% moisture to survive
Bacteria and mold
___ needs 20% moisture to survive
Yeast
What is oven/plate drying
Food spread on shelves in kilns or drying rooms. Hot air is blown over and through the food
What is spray drying
Used for liquid products
Spray noss sprays very tiny droplets of the product into a hot chamber and the high temp immediately dries the droplets
Dried droplets are collected from the bottom of the chamber
What is drum drying
Used for starches like mashed potato flakes and instant oats
Product is evaporated and then poured over large heated drums that rotate until the product dries into thin layers on the surface
Product is further ground to obtain powder
What is freeze drying
Food is frozen, then placed in a vacuum where the ice is evaporated via sublimation
What is the most effective drying method and why
Freeze drying, because it is not exposed to high heat so more vitamins remain intact
Name 3 types of drying pretreatments
Physical - cracking skin of fruits
Blanching - deactivates enzhmes that cause browning
Chemical - sulfur solutions to prevent browning and prevent loss of vitamin A and C
What are 4 methods of thermal processing
Sterilization
Pasteurization
Blanching
Canning
What is sterilization
Complete destruction of micro organisms through extended heat treatment or use of chemicals
Food is exposed to wet heat to reach temp of 121°C for 15 min
What is the shelf life of commercially sterile foods
2+ years
What is pasteurization
Heating food to a specified high temperature for a short time
Between 80-90°C
What is the main difference between sterilization and pasteurization
Sterilization = low temp Pasteurization = high temp
True or false: pasteurized food is not sterile
True
“High temp short time” or “ultra high temp” pasteurization is also called ____
Flash pasteurization
What is blanching
A quick heat treatment applied to vegetables and fruit to inactivate natural food enzymes that affect colour and texture and to decrease oxidative degradation of food
Blanching is often used for what type of food
Frozen fruits and veggies
What is canning
Who does have a temperature above 110°C for a number of minutes
True or false: canned food is considered sterile
False
What is traditional canning
A two-step process that involves packing food into containers which Are then sealed and heated to destroy all microorganisms
What is aseptic packaging
Food is batch heated in a sterile fashion and then placed in sterilize containers
What are the two methods of home canning
Boil water processing
Pressure canning
The method of tang chosen is often dependent on _____
The pH of the food
Fruits and veggies with a pH below 4.6 would use what type of canning
Boiling water processing
Meats, fish, poultry, and vegetables with a pH higher than 4.6 would use what type of canning
Pressure canning
True or false: C. Botulinum cannot survive in neutral environments
False, it cannot survive in acidic environments
What is refrigeration
Slows the chemical, physical, and biological reactions that shorten the shelf life of food
What is the ideal fridge temperature to slow microbial growth
Less than 4°C but no lower than 0°C
True or false: refrigeration prevents the growth of molds
False
What is freezing
Involves cooking food to temps that prevent growth of microbes because it makes water unavailable to the microorganisms
True or false: freezing does not kill microbes but just prevents them from growing
True
What is the ideal temp to freeze foods at
18°C
What is another name for lyophilization
Freeze drying
What is freezer burn
When water evaporation from the frozen food goes into the air spaces and creates ice crystals
What is irradiation
The exposure of foods to ionizing radiation in the form of X rays, gamma rays, or electron beams
What unit is irradiation measured in
Kilograys
Effects of irradiation on water content
Produces hydroxyl radicals, which can interact with other molecules in the food to produce off-odours and off-flavours
Effect of irradiation on lipids
Causes rancidity
Effect of irradiation on proteins
None
Effect of irradiation on carbs
Some structural properties may be reduced (ex. Gelling ability)
Nutritional value remains the same
Effects of irradiation on vitamins
Vitamin A C E and thiamin will break down
Effects of irradiation on physical properties
Changes in texture, colour, flavour
True or false: irradiation kills molds, insects, and bacteria so there is no possibility of food borne illness
True
True or false: foods can be irradiated while they are in their packaging
True
True or false: irradiation lowers foods nutritional value, but has no effect on food quality
False, high nutritional value, decrease in quality
What are the only 4 foods approved for irradiation in Canada?
Potatoes
Onions
Wheat/ flour
Spices
Effects of preservation on vitamin C
Damaged by heat, oxidation, drying, and enzymes released when food is cut
Effects of preservation on thiamin
Destroyed by high heat and non acidic conditions
Effects of preservation on riboflavin, niacin, vitamin B6 and folate
Sensitive to heat
Name 5 new technologies in food preservation
High pressure High pressure/ high temp Non thermal Continuous microwave Antimicrobial chemicals
What is high pressure preservation
High hydrostatic pressure processing or ultra high pressure processing
Food is placed under uniform pressure that is enough to destroy microbes
What is high pressure high temp preservation
Pressure assisted thermal sterilization (PATS)
Can kill C. Botulinum
What is non thermal preservation
UV irradiation, pulses light and ultrasound
What is continuous microwave preservation
Food is passed through a tube and microwaves are directed to the center of the food
Heats food from the inside out
What is antimicrobial chemical preservation
Sprayed on foods or food are dipped into solution
Can be natural chemicals
What is glass made of
Heated silica + sodium carbonate + stabilizers
What is paper made of
Pulped cellulose fibers
What is plastic made of
Polymers of H, C, O, or Si
What is modified atmospheric packaging
Food is packaged in wrap that oxygen cannot permeate
Oxygen is removed from the package and replaced with carbon dioxide or nitrogen
True or false: modified atmospheric packaging prevents the growth of all microorganisms
False: anaerobics may still grow
What are edible films
Coatings that are applied to foods that provide benefit to the food and can be consumed by the user
Give 2 examples of edible coatings being used
Chitosan
Wax on fruits
What is intelligent packaging
Interacts with the external or internal environment of the package
Sensors report on the environment within the package
What is active packaging
Not only sense changes within a product like intelligent packaging, but can also correct the change
What is source reduction
Manufacturer uses less material to package items and in shipping
What is composting
Food scraps created by processing
What is recycling
Manufacturers using packaging materials that are recyclable, and then the consumer recycling the packaging
