Sterilization in pouches
Everything you need to know about sterilization of food packaged in pouches
The purpose of this article is to inform you about the special features of this plastic container with regard to the production and marketing of gourmet preserves and/or ready-made meals. Of course, we will focus on pasteurization and sterilization processes when using this type of container so that you can decide whether or not it is the right choice for your products.
Flexible containers for canned food and ready-made meals
Pouch is an Anglo-Saxon term that in our language means bag. In general, pouches, also called doypacks or stand-up pouches, are flexible containers with three seals that are characterized by their ability to stand upright on their base.
It is believed that the history of this type of flexible container began with the invention of cellophane in 1900 by Swiss chemist Jacques E. Brandenberger. Cellophane is a transparent and flexible film obtained by regeneration of cellulose and is mainly used as packaging or wrapping.
After 12 years of research, Brandenberger finally succeeded in patenting this natural polymer. That same year, in the United States, cellophane began to be used to wrap candy.
That was the first step in the search for lighter and easier-to-stack containers, allowing more products to be transported at lower cost. And all this was possible thanks to the development of petrochemical industries and the creation of new machinery.
Nowadays, more and more companies are using pouches to package their preserves and ready-made meals, as this type of container offers multiple possibilities and advantages.
Types of flexible containers for food
There is a wide variety of flexible containers for food products on the market. There are different models and sizes, ranging from 33 ml to 1.5 liters.
As mentioned above, these containers have three seals, two longitudinal seals on the sides and one on the top. And they are made with:
- Two layers of plastic film:
- One layer of polypropylene (PP) which is a thermoplastic polymer suitable for pasteurizing, sterilizing, modified atmosphere packaging (MAP), blast chilling, freezing, etc.
- And another layer of thermoplastic polyester, usually polyethylene terephthalate (PET).
- A metal foil, usually made of aluminum.
In addition, we can find pouches with tear-off opening, for single use or with zipper closure, as well as pouches with spout and cap. The spout can be positioned vertically or at a corner. In the case of pouches with spouts, these can have different diameters and the size of the caps can be standard or wider, making them safe for children.
Advantages and disadvantages of doypacks for the production of preserves and ready-made meals
There are many advantages attributed to this innovative packaging within the food sector, such as:
- It can be used for packaging different types of food, whether solid, semi-solid, gels, liquids or powders.
- Protects food from moisture, steam, air, contamination and even light.
- It is resistant, easy to handle and has a high conservation capacity.
- It is light in weight, which allows a reduction in logistics costs and emissions.
- It is easy to store and transport.
- It is perfect for displaying products in vertical position.
- 360º image/text communication. A doypack can be printed in its entirety with your logo, artwork and image of the product itself, in addition to the mandatory labeling information. Its design is totally free and allows room for creativity and incorporation of many ideas.
Yes, there are pros but also cons. One of them would be its recycling, which is complicated as it is a multilayer container and also contains other elements such as the zipper closure or caps. It is true that at present there are already 100% recyclable pouches on the market. But it is also true that they have a higher cost per unit.
Another disadvantage is that the product inside the pouches cannot be seen unlike in the case of glass containers. This is an issue that is also being worked on and there are already companies offering semi-translucent doypacks or with transparent sections.
If you still have doubts, please read this article to find out which are the most suitable containers for the production of canned food.
Canned food and ready-made meals in flexible containers
You have probably seen, either on the shelves or in the refrigerators of your local stores, that more and more brands are using this type of heat-sealable bags. Some of the foods we usually find are:
- Salad dressings
- Infant food
- Pet food
- Fruit in small pieces
- Olives
- Ready-to-eat prepared dishes, such as pasta with sauce, meatballs in sauce, creams, etc.
- Stir-fries and sauces
- Soups
- Eggs or liquid egg yolks
Many of the products we find packaged in pouches tend to be sterilized, although this is not a general rule.
Remember that a container does not determine the heat treatment to be applied; what does is the food and the objective of the person who prepares it.
Although there are products that can be found at room temperature and have a shelf life of up to 5 years, there are others that are kept in refrigerators and have a shorter shelf life. This is because they are canned food or ready-made meals that have been pasteurized.
How to produce preserves and ready-made meals in doypacks or flexible containers
Before turning our attention to pasteurization or sterilization of gourmet canned food or ready-made meals, we believe it is appropriate to talk about the previous steps as well as the processing of food.
Just as you prepare the ingredients for your recipe when cooking, you should do the same with your containers. It is important to make sure that you have enough pouches and that all of them are in perfect condition.
Do you have enough containers? Are they intact? Without any deformation or breakage? Are they completely clean? Do the spouts close tightly? Great, now you can start preparing your product.
You may notice that the smell, color, texture or flavor of your food has changed a little during cooking and you are afraid that it will change even more when you pasteurize or sterilize it, but you can always take certain measures beforehand. Here are some tips to avoid organoleptic changes in your gourmet preserves and/or ready-made meals.
We remind you not to cook your product completely, as it will finish its cooking process inside the autoclave during the heat treatment.
Now it is time to package the food in your doypacks. This step will depend on the container you have purchased. Generally, when packaging food products, this type of bag is usually purchased already sealed on the sides, but not on the top, so that the product can be added from above.
After this step, they are sealed with a thermosealing machine and placed in an autoclave to pasteurize or sterilize them. Once the cycle is finished, they can be stored or prepared for transport. This type of container does not need labeling because it has been previously screen-printed with your brand image.
Useful tips for sterilization in pouches, doypacks or flexible containers
If you have chosen pouches with spouts and caps, you should know that, although it is generally necessary to leave an empty space at the top of containers with screw caps, this is not necessary since this type of container is very flexible. Therefore, you can fill the containers to the top with food.
Back pressure plays a very important role in the outcome of the sterilization process. When processing bags, it prevents breakage or deformation of such containers during thermal expansion in high-temperature processing. In bag sterilization processes, where the temperature is regulated by a chamber probe, we recommend applying a single cooling ramp. TERRA Food-Tech® autoclaves allow to reduce the chamber pressure down to a gauge pressure of 1 bar.
How do TERRA Food-Tech® autoclaves help you to sterilize your pouches in a better way?
The various features of TERRA Food-Tech® autoclaves for sterilizing pouches turn a small piece of equipment into a large production partner that is cost-efficient, fast and versatile.
Adjustable F₀ - P₀
Accurately pasteurizes or sterilizes using F₀ and P₀ values
Rapid cooling
Rapid cooling through water shower to avoid product overcooking
Adjustable back pressure
Programmable back pressure value according to container type in order to avoid breakage during processing
Traceability for auditing
Manage and record the process from start to finish with our software
Accurate control
Continuous monitoring of the process thanks to the heart probe
Protection
Excellent security measures for users and their products
Would you like to optimize the production capacity of your canned food or ready-made meal business?
At TERRA Food-Tech® we help you to analyze the productivity level that you will obtain with each model and type of container.
The information obtained in these studies will be very useful when deciding which model of autoclave is the most suitable for your project.
The specific productivity study is also very useful after the acquisition of an autoclave, since it allows us to know the fluctuation of the production capacity if we change the size of the container.
In addition, we create customized stands and racks based on the needs of your business.
Success stories of preserves and ready-made meals packaged in pouches
More and more local producers, farmers and chefs are using flexible containers and an autoclave to prepare their preserves and ready-made meals. In addition to the good image they can generate at commercial level, they offer many other advantages, as you have already noticed in this article.
Visit our success stories section and learn about the experiences of other local producers with this type of container. You will surely find the inspiration to start your own canned food business.
More information on sterilization in containers
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