Lecture 7 Flashcards
Why is food package, whats the purpose?
- provides a barrier/protection from external threats
- extends the shelf life and perserves the nutrients and the quality
- prevents physical damage
- more convient
- branding and labeling
What are the three levels of packaging and give an example of each.
- Primary packages/consumer unit: have direct contact with the food itself, providing the major and inital barrier
- example: metal cans, glass bottles, plastic puches, cardboard cartons
- secondary packing: a physical distrubtion carrier and or diretcly ready to display primary packaging and contains many primary packages
- example: box or case
- Tertiary package: used for handinling, shipping products in primary, secondary or both packaging
- example: stretched wrapped pallet, many cases
What are the functions of primary packaging materials?
Basic function is to allow for ease of use and accessbility of product making it more convient. As well as contianing the product, allowing it to be stored and moved from place to place without loosing product and being damaged by enviromental poultion
Advanced functions inlcudes protection and perservation of the food products and communication to the person buying the product by displaying importanyt information acting as the silent salesperson
What are the three major attributes of packaging materials?
- effenciency: should be effienct both from a production and comerical point of view
- minimal enviormental impact: throughout the cycle, from raw to final disposal
- no negative atributes: are transfered from the materials to the food being packaged
Describe the use of metals as a packing materials: what is used, advantages, applications.
- commonly used metals are steel, aluminum, tin and chromium and are often a mix
- advantegous because they are light, flexible, mechanically resistant and can even be corssion resitant
- can be used as tin foil, canning foods
Describe the use of glass as packaging materials: what is used, advantages, disadvantges, applications.
- made from a rigid, highly viscous liquid in the glassy state, composed mostly of SIO2
- mostly clear some amber or green
- they are advantageous because they are the best barrier against water vapour, gas and odors
- but because they are at heavy risk of breaking they can be seen as disadvantageous
- applications include the use for beverages, oils, wine, syrup, milk, veggies etc.
Describe the use of paper as a packaging material: what is used, advantages, disadvantges, applications.
- includes paper, cardboard, and similar products that are made from pulp, which are enhanced with additional layers fro more protection
- they are from a renewable source, biodgradable, act as a good barrier to light and if coated protect against light and mechincal damage from gases,vapour and water
- if they are uncoated they are very senstitve to humid conditions
- can be used for eggs, pizza,beverages, food delivery etc.
Plastics are used as a packaging material, give the general defintion and the 4 types of plastic with a brief description of each.
- made from long chain or network of organic polymers
1. polyolefinals(polyethylne): used as thin films and in rigid packaging like bottles since they are tough, felxible, slightly transleucent material that acts a good barrier to water vapour and grease but not to gas
2. subsituted olefins (polyvinyl chloride): 2 forms plasticized which is used as stretchh wrapping on trays of meat and fish or unplastcizied for inserts in choclate or cookie boxes as it is resitant to water
3. Polyesters (polyethylene terephthalate): posses great tensile strength, chemical resistance, elastcity all over a wide range of temperatures and are often used for ovenable and microwave safe packaging
4. Copolymers and assemblies: combintation of materials to modifiy and combine the propteries of packaging materierls
describe the use of bio-based materials:what is used, advantages, disadvantges.
- use of regnerated cellulose film (RCF), polylatic acid, biopolethylene, waxes, biopololthylne terephthlate, and polyhydrooxalkonates that re produces via bioprocessing can be platcitsized if need
- advangateous becomes its coming from a renewable source and can be adapted to different foods
- disadvantageous because it has poor resitance to water vapour, gases and not fully fully biodegradable
Plastic is restiant to soprtion-diffusion-depsorption of subtances, what does that mean?
keeps important stuff in like nutrients, flavours, aromas, and keeps stuff thats not wanted out like moisture, microbes,oxygen
What properties can be calculted to see the barrier properties of plastic?
- water vapour trasnmission rate, if high there is a high prevention of condesnation inside
- can calculate oxygen trasnmision rate
- permeability
Describe the relationship between packaging and shelf life.
packaging influences shelf life and packaging is affected by the enviormental factors so therefore needs to be tested in those conditions to reach maxium effectivness
What are the challanges in food packaging?
- not enough mechanical and barrier properties
- lots of plastic use
- most packaging materials are not biodegradble
- lots of waste produced
- more of need for increased shelf life while not effecting the quality of the food
What are emerging solutions for the challanges faced in food packaging?
- nano composites materials: enhance mechanical and barrier properties of food packaging
- active packaging: provides protection and persveration through mehcanism activated condtions like antimicrobial compounds or water absorbers
- intelligient packaging: enhances the communication and marketing function to provide real time data on product quality example are freshness indicatos, sensors
Define corrosion.
presence of oxidizing/reducing agents
