Aluminum Retort Bag

RETORT PACKAGING - PASTEURIZED, STERILIZED PACKAGING
BRAND NEW TREND IN THE FOOD INDUSTRY

1. What is retort packaging?

1.1. Retort, retort bag definition

Retort means applying heat and pressure to exterminate microorganisms. If this effect eradicates most microorganisms, it is called pasteurization; If it wipes out all bacteria, it is called sterilization.

Retort food is a term for food applying the process of packaging food in cans, composite bags made from plastic and metal films (if any), sealing, and cooking the product inside with heat and pressure. There are 2 types of retort:
1) Semi-retort: Temperature below 1210°C, using types of packaging including metal cans, glass bottles, boiling bags, cooking bags, and pasteurized bags.
2) High-retort: Temperature from 1210°C or more, using types of packaging such as metal cans and sterilized bags.

A retort bag, also known as a cook/boil bag or a "flexible can", is a bag containing ready-to-eat food that has undergone pasteurization or sterilization (hereinafter referred to as pasteurized bag - sterilized bag), consisting of multiple flexible layers, which has the potential to replace metal cans while preserving the properties and nutrition of food, including frozen food.

1.2. History of retort bags

Stemming from the need for military food, the US came up with the idea and successfully produced sterilized packaging in the 60s. Around 1980, the technology of creating retort bags was approved by the US Food and Drug Administration for widespread production in the US. Up to now, the packaging industry and the food industry around the world are increasingly improving and raising the bar.

Saigon Food Joint Stock Company (Saigon Food) is the pioneer in this field in Vietnam. The representative product of Saigon Food is instant porridge. Ms. Le Thi Thanh Tam, General Director of Saigon Food, stated to Dan Tri News that Saigon Food's instant porridge products are superior to many other products currently on the market because they do not use chemicals. The reason behind this is that the packaging can withstand the absolute sterilization process.

Convenience, deliciousness, and safety make ready-made foods very popular in the modern era where people are as busy as they are nowadays. This shows that the increasing demand for ready-to-eat foods has led to a sharp increase in the demand for sterilized packaging. Therefore, the retort packaging production market is promising and has potential.

2. Structure and required properties of retort bags

2.1. Required properties of retort bags

Sterilized packaging is regarded as one of the most important advancements in packaging technology. It offers the opportunity to replace metal cans and glass jars with easier-to-use pouch packaging. Therefore, it has the following characteristics: light, easy to pack, and can be designed as a sturdy stand-up bag to replace traditional heavy metal cans. Important properties of this type of packaging should have:

+ Low oxygen permeability, low moisture permeability

+ Low water absorption

+ Resistant to leakage of fats, oils, and ingredients in food

+ The weight of the bumper should be light

+ No residual solvents, PP film production chemicals are required to be treated without catalysts before being used for food

+ The binder must not penetrate the food

+ The structure of materials for packaging production must meet standards when used for food

+ Can be soldered and sterilized

+ Mechanical properties ensure resistance to physical impact during packaging, pasteurization/sterilization, storage, and transportation

2.2. Structure of retort bags

Most retort packaging is currently in use in two forms: aluminum structure (with Al) and transparent structure (without Al)

2.2.1. Aluminum structure

This is a form of structure with aluminum film grafting, in which the translucent side of the aluminum film is exposed to the outside of the package. This type of structure can effectively prevent the permeation of oxygen, water vapor, and light, increasing the efficiency of food preservation.

However, aluminum films are brittle and do not have heat-sealing properties, so they are often coupled with other films to protect Al and increase solderability.

Popular structures of this form include:

• PET // Al // R-CPP
• PET // Al // PA // R-CPP
• PET // PA // Al // R-CPP

2.2.2. Transparent structure

Transparent retort packaging allows consumers to see the product inside. This form of packaging is still resistant to bacteria because the bag still undergoes the sterilization process. However, the ability to prevent the permeation of oxygen, water vapor, and light is not as good as the aluminum structure. This type of packaging is suitable for food with a short shelf life and optimizes packaging costs.

Popular structures of this form include:

• PA // R-CPP
• PET // PA // R-CPP

Note: With this structure, it is advisable to choose the structure with the outermost PET layer if affordable. The reason is that PET film has heat resistance, and moisture resistance, along with the ability to print at high speed. This makes PET the perfect protective layer for the inner PA film.

3. Pros and cons of retort bags

3.1. Advantages of retort packaging

Today, retort packaging is gradually becoming popular in the food industry and has the potential to replace metal cans and glass bottles because of the following advantages:

3.1.1. Good food preservation

The retort bag is also a type of composite film packaging that uses a special membrane that is resistant to temperature during the sterilization process. The ability to preserve food in retort bags is shown through:

+ Good oxygen resistance, high moisture resistance, and resistance to the penetration of fats, oils, and ingredients in food

+ The ability to transfer heat quickly allows food sterilization up to 40% faster than the canning method (using glass jars or metal cans)

+ Reducing nutrient loss can preserve food freshness, taste, texture, and aroma without the use of food preservatives

+ Longer shelf life of food, more than 3 months

+ The product can be stored at ambient temperature, good for freezing or heating food

+ The sterilization process from bag making and food packaging reduces cooking time and  the time using heat to kill microorganisms as usual

3.1.2. Handy and resource-saving

With a lightweight, thin film structure, and easy-to-pack, retort packaging makes the process of storage and transportation simple, and easy to fold into cartons/boxes, saving transportation costs and efficient storage. The retort bag accelerates the production process by 40% which saves more energy than packing in boxes/cans. This type of packaging is easier to cut and open than cans. At the same time, it helps to reduce cooking time and sterilization time, so it is extremely convenient for the busy life of most consumers nowadays.

3.1.3. Various designs

The retort bag is also a type of composite film packaging so it also has a variety of designs. The bag can be designed in the form of a zipper bag with standing jute, a three-sided zipper bag, a three-sided bag, a back-glued bag, etc, and can be vacuumed or not vacuumed depending on customer requirements. At the same time, it brings convenience and is eye-catching which makes a strong impression on consumers.

Printed images are sharp and beautiful, using special inks to ensure that they can withstand pasteurization and sterilization conditions without affecting the quality of the bags and food packed inside.

3.2. Disadvantages

The retort food production process needs investment in modern machinery and equipment for the pasteurization-sterilization process to ensure the quality of the product. The biggest obstacle is the large capital investment for machinery, the packaging process is slower and more complicated than the metal box packaging process. The heat treatment process is complex because many parameters need to be monitored to ensure optimum temperature is reached.

Pasteurized-sterilized packaging is usually thinner and lighter than metal cans which means the bag is more easily punctured by sharp objects than using cans/boxes. Therefore, during transportation, it is necessary to pack outside to ensure safe transportation.

3.3. Application of retort packaging

Nowadays, retort packaging is gradually becoming popular in the food industry and is increasingly preferred by consumers because of its convenience. They are used to store pre-cooked foods and when used can be eaten immediately, reheated in the microwave, or combined with other foods. Retort packaging application including:

+ Porridge, soup container

+ Sauce container

+ Meatballs container

+ Beef stew sauce container

+ Hotpot broth Container

+ Contain sausage

+ Fresh milk, drinkable yogurt, etc container

4. Reputable retort packaging manufacturer

With its advantages, retort bags are increasingly being used in ready-made goods. This is also a consumption trend for modern citizens with today's busy life.

However, using this type of packaging effectively requires consultancy and careful testing steps. You need to choose a qualified supplier. You must also provide detailed information about the product to be packaged, the conditions for the sterilization or pasteurization; the production process, etc, to be able to come up with a suitable packaging structure according to your requirement. The basic requirement is that after going through the packaging process, the packaging must keep its original color, no leaking (when vacuumed), no separating, and the product inside is still well-protected.

Above is the basic information about retort packaging. Customers need this packaging please contact Vinh An Plastic immediately for specific advice. Vinh An is committed to bringing you satisfactory products through the production process that the company is applying.