Upload
jayvee-francisco
View
5
Download
1
Embed Size (px)
DESCRIPTION
food
Citation preview
CHAPTER 21
PRINCIPLES of FOOD PACKAGING
FUNCTIONS of FOOD PACKAGING
Preservation
Protection from physical damage, chemical attacks, and contamination from biological
vectors including microorganisms, insects, and rodents
Must aid consumers in using products
Serves to unitize or group product together in useful numbers or amounts
Must be able to communicate and educate
Must be efficiently filled, closed, and processed at high speeds in order to reduce costs
REQUIREMENTS for EFFECTIVE FOOD PACKAGING
1. Nontoxic
2. Protect against contamination from microorganisms
3. Act as a barrier to moisture loss or gain and oxygen ingress
4. Protect against ingress of odors or environmental toxicants
5. Filter out harmful UV light
6. Provide resistance to physical damage
7. Transparent
8. Tamper-resistant or tamper-evident
9. Easy to open
10. Have dispensing and resealing features
11. Easy to dispose
12. Meet size, shape, and weight requirements
13. Have appearance, printability features
14. Low cost
15. Compatible with the food
16. Have special features such as unitizing groups of product together
TYPES of CONTAINERS
1. Primary Container
Comes in direct contact with the food
Nontoxic and compatible with the food and cause no color, flavor, or other
foreign chemical reactions
2. Secondary Container
An outer box, case, or wrapper that holds or unitizes several cans, jars, or pouches
together but does not contact the food directly
Make possible to distribute in glass jars without the corrugated secondary carton
to protect against breakage
Must protect the primary containers from damage during shipment and storage
Must prevent dirt and contaminants from soiling the primary containers
Must unitize groups of primary containers
3. Tertiary Containers
Group several secondary cartons together into pallet loads or shipping units
Aid in the automated handling of larger amounts of products
FORM-FILL-SEAL PACKAGING
Containers may be formed in-line by assembly from roll stock or flat blanks just ahead of
the filling operation in the food-handling line.
Today most flexible containers, whether made from paper, foil, or plastic resulting in
great savings in handling labor, container transportation costs, and warehouse storage
space
Milk Carton System – cartons were assembled from coated fiber flats, filled, and sealed
HERMETIC CLOSURE
Hermetic – a container that is sealed completely against the ingress of gases and vapors;
impervious to bacteria, yeasts, molds, and dirt from dust and other sources
Non-hermetic – prevents entry of microorganisms; allow some gases or vapors to enters
Hermitically sealed containers not only protect the product from moisture gain or loss
and oxygen pickup from the atmosphere but are essential for vacuum and pressure
packaging
Most common are rigid metal cans and glass bottles
FOOD-PACKAGING MATERIALS and FORMS
Metal, glass, paper and paperboard, plastics, and mirror amounts of wood and cotton
fiber
Variety of Forms: rigid metal cans, flexible aluminum foils, glass jars and bottles, rigid
and semi-rigid plastic cans and bottles, flexible plastics made from many different films
used for bags, pouches, and wraps, paper, paperboard, and wood products in boxes,
pouches, and bags, and laminates or multilayers in which paper, plastic and foil are
combined to achieve properties unattainable with any single component
Encompasses the equipment and machinery for producing or modifying certain
packaging materials, for forming them into final containers, for weighing and dispensing
of food materials, for vacuumizing or gas flushing the containers, and for sealing the final
packages
METAL
Two basic alloyed metals used: steel and aluminum
Steel – used primarily to make rigid cans; can withstand the pressure stresses of retorting,
vacuum canning
Beading – horizontal ribbing to increase rigidity
Aluminum – used to make cans as well as thin aluminum foils and coatings; resistant to
atmospheric corrosion, and can be shaped or formed easily; works well in very thin
beverage cans that contain internal pressure
Tin Can – steel used for cans are coated with a thin layer of thin to inhibit corrosion
METAL CANS
Its hermetic property is a remarkable engineering achievement when one considers that
cans are manufactured and later sealed at speeds exceeding 1000 units per minute and
defective cans are fewer than one in many tens of thousands.
CAN CONSTRUCTION
Two basic types of metal cans based on method of construction; Three-piece and Two-
piece
Three-Piece Cans – comprised of a cylindrical body and two end pieces
Two-Piece Cans – made from one single body and end unit and one can end piece which
is applied after the can is filled with product; do not have side seams
CAN CORROSION
Steel cans are protected from corrosion by rust pitting by a thin electronically deposited
coating of thin
Tin has been replaced by chromium or base steel by giving special rust-inhibiting
treatment called “passivation” – tin-free – lower cost
CAN SIZING
Cans are given standard size designations based on their diameter and height in whole
inches plus sixteenths of an inch.
Example: A 303 by 404 can has a diameter of 3 3/16 in. and a height of 4 4/16 in.
GLASS
A chemically inert and an absolute barrier to permeation of O2 or water vapor
Limitations: susceptibility to breakage, which may be from internal pressure, impact, or
thermal shock, its weight which increases shipping costs, and the large amounts of energy
required for forming into containers
Primarily formed from oxides of metals, with the most common being silicon dioxide
which is common sand
Controlled mixture of sand, soda ash, limestone, and other materials made molten by
heating to about 1500 degC
GLASS CONTAINERS
Hermetic, provided the lids are tight; lids have inside layers of a soft plastic material
which form a tight seal against the glass rim.
Vacuum packed, and the tightness of the cover is augmented by the differential of
atmospheric pressure pushing down on the cover
PAPER, PAPERBOARD, and FIBERBOARD
Paper – thin, flexible, and used for bags and wraps
Paperboard – thicker, more rigid, and used to construct single-layer cartons
Fiberboard – made by combining layers of strong papers and is used to construct
secondary shipping cartons
Corrugated Paperboard – used to construct shipping cartons because of the wavy inner
layer of paperboard used in its construction
Kraft Paper – the strongest of papers and in its unbleached form is commonly used for
grocery bags; commonly used as butcher wrap; Kraft – German word for strong
Greaseproof or Glassine Papers – paper pulp that undergo acid treatment to modify the
cellulose and give rise to water- and oil- resistant parchments of considerable wet
strength
PLASTICS
Plastics – a broad group of materials that have common property of being composed of
very large long-chain molecules
Can be formed in an almost infinite number of shapes
Copolymers – plastics that combine different monomers into the same polymer molecules
to form materials with combined properties
Homopolymer – if the plastic resin is made of just one type of monomer
LAMINATES
Commercial laminates containing up to as many as eight different layers are commonly
custom-designed for a particular product.
May be formed by bonding with a wet adhesive, dry bonding of layers with a
thermoplastic properties, and special extrusion techniques
Coextrusion – simultaneously forces two or more molten plastics through adjacent flat
dies in a manner that ensures laminar flow and produces a multiplayer film on cooling
RETORTABLE POUCHES and TRAYS
Flexible materials combined to withstand even the adverse conditions of retorting
encountered with low-acid foods
Advantages: shorter retort times, which can produce high quality products and save
energy, lighter weight, increased compactness, easier opening, and easier disposability
Retortable Pouches – constructed of a three-ply laminate consisting of (1) on an outer
layer of polyester film for high-temperature resistance, strength, and printability, (2) a
middle layer of aluminum foil for barrier properties, and (3) an inner layer of
polypropylene film that provides heat-seal integrity
Retortable Trays – constructed from multilayers of polymers, one of which is ethylene-
vinyl alcohol to provide an oxygen barrier; often sealed with a polymer-foil laminated
film
EDIBLE FILMS
Spray drying various flavoring materials emulsified with gelatin, gum Arabic, or other
edible materials to form a thin protective coating – microencapsulation
Used to coat fresh fruits and vegetables to reduce moisture loss and to provide increased
resistance to growth of surface molds
WOOD and CLOTH MATERIALS
Woven cloth and cotton bags are used to a limited extent, mostly for bulk shipment of
grains and flours.
Wire-wound wood strips have been used to make crates for fresh fruits and vegetables.
Solid wooden crates are used for transporting iced fish.
PACKAGE TESTING
Measure quantitatively the protective properties of packaging materials and entire
containers; divided into chemical and mechanical parameters
Chemical Tests – used to identify plastics, determine if portions migrate to foods, and
measure resistance to greases
Mechanical Tests – barrier properties, strength, heat-seal ability, and clarity
Water vapor transmission rates (WVTR) can be measured by sealing sheets and films
across the opening of a vessel that contains a weighed quantity of a desiccant material.
Gas transmission rates can be measured by an instrument which uses the test film to
separate an inert gas from the test gas.
Resistance of packaging films to acids, alkalies, and other solvents can be measured
quantitatively by incubating the films in the solvent under controlled conditions and then
determining either the degree of leaching of the film into the solvent or changes in the
physical properties of the recovered films.
PACKAGES with SPECIAL FEATURES
Package that have some type of added convenience feature. Ex. “boil-in-bag” package
Permeable to grease, nontoxic, compatible with the food, transparent, capable of being
evacuated and heat-sealed under vacuum, attractive, tamper-evident, easy to open and
dispose of, light in weight, requires little storage space, and is low in cost
Its materials and seals withstand freezing temperatures and the expansion of foods frozen
within it.
The plastic shrink package protects food against contamination and yet lets the costumer
see the meat.
MICROWAVE OVEN PACKAGING
Must be transparent to microwaves and able to withstand the temperatures encountered in
heating foods in the microwave oven
Most common used materials are made of plastics.
Disadvantage: heating surface does not get hot itself
Susceptors – cause foods to brown in a microwave oven; improves the quality of popcorn
popped in a microwave oven
HIGH BARRIER PLASTIC BOTTLES
Do not break when dropped, and can be incinerated without the production of toxic,
corrosive, or noxious compounds beyond those found in burning household or municipal
trash
Reduces cost throughout the production and shipping channels
Allow for easier dispensing of viscous products such as ketchup
ASEPTIC PACKAGING in COMPOSITE CARTONS
Aseptic Packaging – aseptically filling the sterilized composite paper cartons with sterile
liquid products
Allows food to be packaged in relatively inexpensive flexible containers which do not
require refrigeration
The packaging material is made from laminated roll stock consisting of polyethylene,
paper, aluminum foil, and a coating of ionomer resin.
MILITARY FOOD PACKAGING
Packages that simplify preparation and consumption of the food
Can undergo a rapid exothermic reaction
Too expensive
PACKAGING and COMMUNICATION
Determines a product’s sale or rejection
Package’s color and symbolism must be considered
FOOD LABELLING
It is important to ensure that the consumers are given complete and useful information of
the products they purchased.
3 types of Information n the food package:
1. Mandatory information required by the different laws governing food packaging and
labeling
2. Optional or voluntary information
3. Information by the manufacturer that helps the consumer understand the use of products
such as instructions for preparation and recipes
Information that must appear on the labels:
1. Food name
2. Net quality of contents
3. Ingredients – list of ingredients in descending order by weight
4. Company Name
5. Product dates
Pull dates – last date the product should be on sale
Best if used by – shelf life for the optimal quality
Pack date – date food was packaged
Expiration Date – last date on which the product should be eaten
6. Nutrition Information – nutrition facts, nutrient content claims and health facts
7. Other information such as grades of food products, bar code or product code, religious
symbols which indicates the product meets certain religious qualifications, warning
labels specifically such as ingredient labeling which can be allergic to some consumers
SAFETY of FOOD PACKAGING
MIGRATION from PLASTICS
Plastics are not completely inert to foods.
Plastics must have approval from regulatory agencies for the intended use.
CONTAMINATION
Preventing contamination of food and its recontamination depends primarily on
packaging.
ENVIRONMENTAL CONSIDERATIONS
Landfilling – the most common way of disposing of solid waste
Source Reduction – the use of less material when packaging foods
Metal and glass containers are heavy and require considerable energy to transport and
melt.
Recycling of glass is not always feasible because of its lower economic value.