topic 18 Flashcards
Food Packaging and Preservation
why we need food packing
u Enables transportation and storage, convenience
u Reduce food waste
u Functionality
u Environmental concerns
u Applications for military and space
how could food packaging help protect the food?
Chemical, biological, physical
Tamper resistant
Increases shelf life (oxygen, light, moisture barriers
what is smart packaging?
how could smart packaging help most?
when we need a food recall
what is MAP
modified atmosphere packaging
how could MAP help with food preserve?
Reduce oxygen and increased CO2 and N2, remove air and replace(Gas barrier materials),
Gaseous environment changed to slow respiration, reduce microbial spoilage, enzymatic reactions, oxidation
MAP has 2 kinds, High gas permeable (respiring) or low gas permeable, yes or no
yes
vacuum packing is good for preserve meat, why?
hermetically heat sealed, O2 less than 1%, the pigment-myoglobin won’t change color
containment of packaging
regulation of food packaging in Canada-FDR Division 23, Food Packaging Materials
No person shall sell any food in a package that may yield to its contents any substance that may be injurious to the health of a consumer of the food.
who takes the responsibility of safety?
food seller, Does not fall under food additives; not subject to premarket clearance (except infant formula and novel food)
packaging materials
plastic, glass, paper and paperboard, metal, combined, Edible films and Coatings
what should we consider when we choose the packaging materials?
1.Consider food quality (flavour),
2.food processing methods,
3.consumer
wants,
4.cost,
5. environmental impact
what is plastics chemically?
organic polymers, it has Variable chemical compositions, fabrication processes, Various shapes, rigidity
what is the most common plastic?
PE: polyethylene
what is BPA?
Bisphenol A, evidence is not clear, but most products have removed
what is a biobased plastic?
Renewable, biodegradable (cornstarch, sugar beets)
good things of a glass packaging
- chemically insert(stable)
- recyclable
- clear and have many shapes
bad things of a glass packaging
heavy, breakable, expensive
where do we use paper/paperboard as packaging?
Milk cartons, bags, corrugated boxes, cereal boxes
how is paper made?
Cellulose fibres derived from wood
good things as a paper packaging
Can be treated, laminated, coated for barrier, heat properties
examples of metal packagings
Aluminum, aluminum foil, tin-free steel
good things of a metal packaging
Lightweight, resistant to corrosion, recyclable
what consists a combined food packaging material, e.g: tuna bag
Polyester (strength)(outside), aluminum foil (barrier),
polyolefin (heat seal)(inner), all laminated together with adhesives
good things of a combined food packaging
Thin and permits sterilizing temps more quickly than canning so product is fresher and firmer
what are edible films and coatings?
Starches, gums, gluten, soy protein, casein, waxes
could Edible films and Coatings replace non-edible packagings?
NO
good things of a edible food coating
Inhibit moisture migration, aromas, lipids, Act as antimicrobials, antioxidants, flavour
how plastic packagings could do bad to environment?
Plastic and microplastics (<5mm) infiltrating zooplankton and other marine life
strategies for waste management
reduction, elimination, lighter, reusable, recycling, incineration, pay, this Success depends on government, industry, public support
what is a food spoilage?
Inedible, hazardous due to chemical changes, Growth of microorganisms, enzymes, oxidation, mechanical damage, pests
10 food preservation techniques
- cold storage
- freezing
- pasteurization
- canning
- MATS
6.Drying - Freeze drying
- preservations
- irradiation
- HPP
good things for a cold storage?
u Unfavourable to the growth of microorganisms
u Chilling can extend shelf life
u Slows enzyme activity
u Can be precooked or minimal processed
u Refrigeration ~3°C
u In combination with other methods such as atmosphere, packaging, preservation, etc.
what’s a range for a refrigeration?
~3°C
example of a cold storage: Sous Vide Considered extended shelf life
Sous Vide
‘Under vacuum’, Slow, controlled cooking of foods in sealed, vacuumed package Followed by quick chilling and refrigeration
the temperature of a freezing
About -18°C
what kind of food should use freezing?
Seafood, poultry, meat, vegetables, fruits, baked goods, prepared foods
what is the effect of the size of the container and freeze time?
Large containers – longer freeze time
Small containers – shorter freezing time
how would the freezing time effect the food?
longer freezing time=larger ice crystal=break food structure
good thing of a freezing
Much longer preservation than cold storage
High retention of flavour and nutritive value
what’s the requirment of the containers for a freezing process?
pliable, airtight, microwave or heat safe
different freezing methods and ice crystals
slow
fast
cryogenic
should we blanching before freezing?
- Blanching inactivates enzymes prior to freezing which could normally have deleterious effects
- but Prevents browning, destroys pigments, prevents unpleasant
flavours/odors - Shrinks vegetable tissue to pack more easily, expelling air to reduce
oxidation, decreases microorganisms
why should we use acid with fruits other than blanching?
Fruits can be mushy after blanching, instead use acids
how to deal with the freezer burn?
packaging
what is freezer burn?
Loss of moisture through sublimation
Dehydration of food
Change of texture, discolouration, off flavour
what is D value in the Sterilization (Aseptic) chart
D-value indicates time required at a certain temperature to kill 90% of
microbe or reducing by 1 log
what controls the D-value?
D-value depends on microbe species
what is the Z value in chart?
Z-value is the change in temperature needed to alter D-value by 1 log
would pasteurzation achieve 100% sterility?
no
what is log reduction?
safety treatment for acidic food when canning
boiling water is fine 100
safety treatment for low acid food
water temperature must be above 100(pressure canning)
what is retort in canning process
Can agitate or rotate to speed heat penetration
what is MATS in food packaging?
Microwave Assisted Thermal Sterilization
good things of MATS
Steam and microwave to rapidly sterilize food
Better organoleptic properties
Reduce the need for added sugar/salt to hide
drying as a food preservation
Removal of moisture (<30% moisture) – sun, oven, air, etc
inhibits microorganism growth
what is freeze drying
Rapid Freezing, sublimation drying (low pressure vacuum and mild heat),
desorption (secondary drying at a higher temperature)
Contains 1-4% moisture
Organoleptic properties preserved well
Light weight and shelf stable
what is osmotic drying?Craisins
strong syrup draws water out of food and then food is dried with air
Preservatives
Acids(pickling), Sugar, Salt and spices
Irradiation
‘Cold pasteurization’,WHO has concluded safety, Not enough energy in ionizing radiation to split atoms, therefore not radioactive
what is the mechanism of irradiation
Exposed to ionizing radiation to reduce microorganisms, destroy pathogens, extend shelf life, reduce insect infestation, Removes an electron to form an ion breaking DNA and killing microbe
is irradiation radioactive?
NO, Not enough energy in ionizing radiation to split atoms, therefore not radioactive
good things of irritation
Preserves organoleptic properties
u Label ‘treated with radiation’ or ‘treated by irradiation’
what is HPP?
High Pressure Processing, use extremely high pressure kills microbes
