Ready-to-Eat (RTE) and Ready-To-Serve (RTS) food – e.g. Idlis, dosas, pav bhaji, meat products like pre-cooked sausages, ham, chicken products, curries, chapattis, rice, vegetables like aloo chole, navratan kurma, channa masala etc.
Ready-to-eat snacks like idlis, dosas, pav bhaji etc. are sold across the counter and have a very short shelf-life, hence the packaging requirements of these products are different from those of ready to eat products like curry rice, upma, vegetable biryani etc., which are retort processed for longer shelf-life. Products like idlis, dosas, pizzas are packed in packaging materials having low water vapour and oxygen permeability, odour and grease resistance, and good physical strength.
- Various Packaging Laminates/Composites used :
- Foil / adhesive / paper coated with heat sealing vinyl resin : Good moisture barrier, runs well on machine. For use as over wraps for confectioneries
- Foil / adhesive / paper / polyethylene (extruded) : Good moisture barrier, runs well on machine. For use as Fin-sealed pouches and sachets – soups, etc.
- PE / Foil / adhesive / paper : Heat seals by the wax bleeding through the tissue. For use as Over wraps for confectionery
- Foil / adhesive / paper / micro-wax comp. /tissue (20 g/m2) : Low WVTR. For use as Over wraps for biscuits, etc.
- Foil : Excellent WVTR, good machinability. For use as Candy wrap, biscuit wrap
- Cellophane / wad / cellophane Excellent WVTR, sandwich printing, good machine performance. For use as Bags or pouches for hygroscopic items
- Cellophane / adhesive / pliofilm : Excellent gas barrier, transparent pack. For use in Nut packing with inert gas
- Cellophane/polyethylene : Excellent gas barrier, trapped printing. For Chocolate, etc.
- Polyester film / Saran coated polyethylene : High strength, positive sealing. For Vacuum food Pouches
- Polyester / adhesive / foil / polyethylene : Excellent gas barrier, good heat resistance, good rigidity, aroma retention. For Flexible processable cans
Retort pouch is a special package in which the perishable food items are preserved by physical, and/or chemical means. It is a flexible laminate, which can withstand thermal processing, and combines the advantages of the metal can and the boil-inbag. Ready-to-use retort pouches are flexible packages made from multilayer plastic films with or without aluminium foil as one of the layers. Unlike the usual flexible packages, they are made of heat resistant plastics, thus making them suitable for processing in retort at a temperature of around 121°C. These retort pouches posses toughness and puncture resistance normally required for any flexible packaging. It can also withstand the rigours of handling and distribution. The material is heat sealable and has good barrier properties.
3-ply laminate consisting of PET/Al Foil/PP is commonly used for packaging of ready to eat retort packed food. The product packed in such laminates has a shelf-life of one year. The other materials generally used in retort pouch structure includes nylon, silica coated nylon, ethylene vinyl alcohol (EVOH) and polyvinyledene chloride (PVDC). These materials have high moisture barrier properties and are used successfully for packaging of ready-to-eat high moisture Indian food. Both preformed pouches as well as pouches formed on FFS machines are commonly used. Preformed pouches are of flat and stand – up type. The typical structure of these pouches are:
Flat configuration : 12μ PET/12μ Al foil/ 75μ PP
Stand up configuration : 12μ PET/9μ Al foil/ 15μ OPA/60μ PP
The pouches are printed in attractive colours. The retort pouch is a space saving package by
value of its design. It is a good substitute for tinplate cans as it eliminates the need for the addition of brine in the food.