When picking up a RTE food packet have you ever wondered about the packaging it comes in? Or the vital  role  it plays in the preservation and quality assurance of the food inside? With the upsurge of convenient food culture in India, it was a challenge for manufacturers in that sector to device good packaging methods which conserved the freshness of the precooked food and prevent its spoilage and at the same time is easy to carry along. Today, Retort packaging and processing is one of the popular packaging methods for RTE, which originated in the USA and in India was pioneered by the DRDO.

Types of packaging material

A variety of packaging materials are available depending on the nature of the food –whether it is a dry product or a wet product, the ingredients used, intended shelf life and so on. Examples are

  • Aluminum foils
  • Extruded polyethylene
  • Microwavable low density polyethylene (ldpe)
  • Cellophane

These packaging materials began replacing the conventional tins or cans which were cumbersome. Various kinds of packaging are prepared by layering these materials singly or in specific combination according to the requirement of the food product.

Criteria for a good packaging material

The main criteria for a good packaging material is that  it should

  • Be impermeable or have very low permeability to oxygen and moisture thus inhibiting oxidation or chemical changes and microbial spoilage
  • Prevent loss of flavour of the food
  • Be inert or in other words not react with the ingredients of the food or leach any chemicals
  • Be of light weight and flexible so as to make portable packages.

What are Retort  pouches made of?

A retort pouch is constructed by laminating (lmultiple layering) of plastic and metal foils. It is a flexible pouch which can withstand very high temperatures. Food is sealed in these pouches and then sterilized in a retort.

Normally a retort pouch has three main sections:

  1. An outer layer of made of polyester or nylon which makes it  printable and hardy
  2. Central layer of aluminium foil, which makes it resistant to oxygen and moisture
  3. An inner layer of thermo sealed polypropylene which is safe  as it does not release any chemicals and is heat resistant.

Origin of Retort pouches

In 12978, retort pouches were invented by the United States Army for packaging Meals, Ready- to-eat(MREs) for their personnel stationed in places where food amenities are unavailable. Slowly these   pouches were embraced by the commercial food industry globally.

Thermal processing of retort pouches

A retort means a vessel and in this context implies a closed vessel in which food is heat or thermally processed.  First, the food is packed and sealed into the retort pouches. Then the pouches are sterilized in an autoclave(a closed vessel) under high pressure and temperature for a specific amount of time. This technique results in the commercial sterilization of the food and ensures a longer shelf life to the product, preserving its freshness and quality.

Pioneering research by DRDO

The DRDO (Defence Research and Development Organization) is an Indian agency which deals with the Armed forces’ research and development. It has an expansive network of research laboratories including DFRL (Defence Food Research Laboratory),Mysore, DFRL manufactures and supplies processed foods to the armed forces and carries out research in the field of  convenience foods, preservation of foods, food packaging and safety and so on.

DRDO considers retort pouches as one of the best available methods of food packaging. It  has researched various materials for manufacturing retort pouches and has also and has designed cost-efficient sterilizers appropriate for small scale industries. Their retort processing technology has been adopted by many Indian food manufacturing industries..

Other advantages of Retort pouches

Since retort pouches are of light weight, their production is relatively energy efficient and cost effective.

Apart from being one of the best packaging methods for RTE foods, retort pouches are recyclable. Due to multiple layers present in retort pouches, it is not possible to recycle these back into other food packages but it could be recycled and reused in textile industries. So next time when you buy a RTE food which comes in a retort packaging, save the pouches and give it to recycling vendors.

So rest assured that you are buying a safe product when you buy a retort packaged RTE meal!