11.food Packaging Materials For Meat, Milk

11.FOOD PACKAGING MATERIALS FOR MEAT, MILK

Introduction: ◦

The challenge to the packaging industry is to deliver the nutritious milk to the consumer in most economical, hygienic, safe and environmentally friendly package.

◦ There are two main types of packaging systems for fluid milk one is traditional bottling system in which container is to be returned and other is one way delivery in which container is disposable and does not travel back to the dairy. ◦

History of milk packaging : ◦ At early stage-cow’s udder was the basic container ◦ Development of containers in 1860-70 for distribution.

◦ First significant development in milk packaging- process for sterilized milk ◦ In the third decade of this century- bottling of pasterurized milk developed ◦ Development and introduction of plastic materials for packaging in the dairy industry 1940

status ◦ 46% of the total milk production in the country consumed as fluid milk ◦ Only 15% of milk is packed. ◦ Of this, the flexible pouch accounts for aprx 94% ◦ 89% of the households in india consume loose milk

◦ Only 9% households use packaged milk.

Basic Packaging materials used ◦ Paper and paper based products ◦ Glass bottles ◦ Tin plates ◦ Aluminum foil ◦ Timber ◦ Plastics

◦ laminates

Liquid milk :  glass bottles  Paper laminate for tetra paks  Flexible pouches Milk powder:

tin plate containers Metalized aluminum foils Lined cartons Bag-in box: powder filled in laminates

Liquid milk: ◦ Flexible pouches 92%, glass bottles 7%, and aseptic packaging 1% ◦ Plastic materials in aseptic packaging of milk product are polyethylene, polypropylene, polystyrene etc. ◦ Economic saving realized

Cream: ◦ Shelf life of refrigerated creams 1-2 days ◦ Packaging consists of PE coated paperboards ◦ In india, cream generally packaged in 150ml glass bottles, individual pack or consumer’s own container ◦ Tin plate containers also used for larged sixes

◦ Whipped creams sold in AEROSOL cans and PE tubs ◦ Imitation cream packed in wax-coated paperboard cartons.

Whole milk powder: ◦ Produced either by roller or drum process ◦ Rapid flavor deterioration due to oxidation ◦ General procedure is to remove oxygen by subjecting the product to vacuum within 24 hours of drying ◦ Less than 2% final oxygen considerd satisfactory ◦ Coating with an impermeable material or the addition of antioxidants also done.

Ghee: ◦ Upon prolonged storage, ghee undergoes lipid deterioration ◦ Tin plate container: protects the product against tampering and being sturdy, can be transported to distant places ◦ Semi rigid containers: provides a moderately long shelf life, lightweight, economical and transport-worthy

◦ Flexible films/ pouches: limited quantities of less than 1kg packed. Most economical.

Paneer: ◦ Short shelf life of about 7days at refrigeration storage and less than 24 hrs at room temperature. ◦ Sachdeva et.al (1991) vacuum packaged paneer blocks of 10x4x6 cm size in polyethylene bags using a vacuum packaging machine.

◦ The body and texture of paneer improves on vacuum packaging. ◦ No deterioration observed upto 30days at 6‡10◦C in vacuum

Khoa: ◦Limited shelf life of 5days at room temperature. ◦Hot filling (80-90◦C) of khoa in tin cans increases shelf life to 14 days at 37◦C. ◦Now a days, high barrier structures/ laminates based on polyester/ ethylene vinyl alcohol (EVOH) / polythene being developed. ◦Tin cans and rigid plastic containers of 15 kg capacity can be used.

Butter: ◦ Pat of butter: most commonly used ◦ Manual-moulded butter: hand packaged

◦ Machine-moulded butter: automated version of hand-packaged butter. ◦ Butter in a dish: most popular for reduced-fat

◦ Mini butter: for markets with limited buying power and high demand. ◦ Jar of butter: for larger quantities.

Cheese: ◦ Cheese is coated with a wax layer to protect from contamination ◦ Cheese may be packaged in plastic film as slices

◦ Also packed as cubes or whole pat in aluminum or tin foil ◦ Primarily transported in cartons.

Future prospects: Thermoform bottle ◦ Made from poly lactic acid (PLA) Advantage of PLA

◦ Degrades within weeks ◦ High stability ◦ Transparency ◦ Wide temperature range

◦ UV resistance ◦ Convenient.

Meat ◦In the packaging of meat two factors have to be considered, Color of meat microbiology

◦ Colour of meat: The association of colour of red meat with freshness has been the dominant factor in retail meat marketing. The loss of bright red colour of meat is known as “bloom”. ◦ Microbiology: The composition of bacteria that is present on meat at the starting of spoilage is affected by the qualities of the tissues on which the bacteria is growing, the composition of atmosphere around the product and the number of bacteria at the time of packaging.

Tray with overlap: ◦ The most common packages for retail fresh meat cuts are trays over wrapped with a transparent film. Meat thus wrapped may keep for approximately 10 days at a temperature of 0⁰ c. ◦ Materials used: ◦ polystyrene foam or clear plastic trays can be used. ◦ Cellophane coated with nitrocellulose on one side can be used for wrapping fresh meat for a considerable period. ◦ Another grade of cellophane with polyethylene coating on one side is also used though it is not much in use.

Vacuum packaing: ◦ Vacuum packaging achieves its preservative effect by maintaining the product in an oxygen-deficient environment. ◦ In anaerobic conditions ,potent spoilage bacteria are severely or totally inhibited on low pH (<5.8) meat. ◦ Thus shelf life of meat can be increased. ◦ Vacuum packaging involves enclosing boneless meat in flexible plastic containers or bags to prevent moisture loss and exclude oxygen from the meat’s surface.

Materials used: ◦Co-polymer coated cellulose/PE film laminate ◦Polyester /PE film laminate ◦Nylon /PE film laminate

Four basic methods are available for vacuum packaging:

◦Shrink bag ◦Non-shrink bag ◦Thermoforming ◦Vacuum skin packaging

Packaging of frozen meat: ◦ Frozen meat is stored and displayed between -10⁰ C and 30 ⁰C at which temperatures microbial growth is arrested. ◦ It is claimed that ionomer film will keep the bright red colour for at least a year if the meat is stored in the dark at -20⁰C. ◦ When frozen meat and meat products are stored without an adequate moisture vapor barrier an opaque dehydrated surface known as freezer burn is formed. ◦ Freezer burn is caused by the sublimation of ice on the surface of the product. it can be eliminated by reducing the head space in the package.

Materials used: ◦ Frozen products have traditionally been packaged in bags, pouches trays, overwraps and plastic-coated paperboard, with polyolefin's being the most common material used. ◦ Vacuum skin packaging is also used for frozen meat products.

Packaging of thermo processed meat Thermal processing at above 100⁰ C usually accomplished under pressure ,is done to prepare commercially sterile meat products. • The packaging of this considers two factors. 1.short-term storage 2.long-term storage

◦ Short term storage Meat products like sausages,nuggets,meat balls, etc can be packaged in pouches made up of PE,PP,PVDC, for short-term storage lasting for 10-12 days at 4 ⁰C. ◦ Long term storage: Meat products like corned beef, corned pork, meat gravies, meat soups, liver sausages, chicken curry, boneless chicken etc are hermetically sealed and cooked to make commercially sterile for long term storage at room temperature.

◦Two types of containers are suited for this purpose. Metal cans Canned meat products are shelf stable for a number of years at room temperature which uses aluminium cans Retort pouches • A retort pouch is a plastic and metal foil laminate pouch that is used as an alternative to traditional industrial canning methods • A retort pouch is constructed from a flexible metal-plastic laminate which is able to withstand thermal processing via sterilization.

References: Golden L. Robertson, Food Packaging Principles and Practice 2nd edition.