Presearch guided by professor Carlos Alberto Rodrigues Anjos, from the Department of Food Technology at the Faculty of Food Engineering (FEA) at Unicamp, and developed by Air Force Major Nelson Pedro Roja Júnior, contributes to the development of a modernization process for operational rations of the Ministry of Defense. The so-called operational rations are used in campaign, combat, abandonment of aircraft and vessels, survival or other convenience situations in the training and instruction of troops deployed in operations in regions where the preparation or arrival of fresh food is difficult or unfeasible. Roja explains that the provision of meals in contingency situations has guided armed forces around the world in order to optimize aspects of quality and food safety, inherent to health requirements and that meet users' sensory expectations.

Food they're used in many situations

Carlos Anjos remembers that in the 70s the then General Staff of the Armed Forces approached the FEA for the first development of operational rations. Around 35 years later, with the discussion in the three Arms of a larger project, about to be implemented, which involves cooperation in the areas of food, fiber optics, vehicle maintenance, infrastructure and technologies, the Ministry of Defense is once again looking for Unicamp.

Anjos states that the dissertation presented here is part of this context of cooperation and that other officers must come so that these studies can continue. The resumption of exchanges with the FEA in 2003 led the Air Force to hold seminars on food throughout Brazil for representatives of the three Arms with the aim of disseminating technologies and changes. According to the professor, these actions motivated the approach to academia.

The research carried out by Roja, which led to the master's thesis that evaluates sterilizable flexible packaging as well as ready-to-eat food on land and for aircraft equipment, was guided by two aspects that are closely related: the selection of the most appropriate packaging and the production and sterilization of food in order to maintain its physical, nutritional and sensory characteristics, in addition to ease of handling and meeting weight and volume reduction needs. Costs were also taken into account, the possibility of using packaging filling and closing equipment and the possibility of including other menus to those already offered.

The work - The research focused on the production of two items packaged in unitary packaging: parboiled rice, which contains onion, oil, garlic and salt, and meat with vegetables, consisting of cubes and sauce of meat, potatoes and carrots. The choice was guided by the fact that meat dishes offer greater operational difficulties in maintaining the desired properties, which if overcome would facilitate the adoption of other menus.

The investigations led to the selection of two equivalent sterilizable flexible packaging available on the market – one imported and the other nationally produced. The initial and final microbial loads of cooked and packaged items and subsequently subjected to a thermal process in an autoclave were below established standards.

Sensory tests revealed good acceptance in relation to appearance, flavor, aroma and general impression, highlighting the texture of rice, beef, vegetables and salt dosage. Carlos Anjos explains that the maintenance of texture, flavor and aroma is due to the thickness of the packaging, which facilitates heat transfer and requires less time in the autoclave to eliminate microorganisms, unlike what happened in the can. This fact surprised Armed Forces suppliers and commanders, aware that their troops often received food mixtures in cans that had been transformed into a formless paste.

In this regard, Carlos Anjos recalls that one of the combat ration dishes consisted of pasta, vegetables and rice, all together, in which none of the components could be distinguished because the mixture required overprocessing which compromised the texture.

Nutritional analysis indicates that the menu is equivalent in caloric value to conventional food prepared in the daily routine and meets the needs recommended for military or civilian consumption during periods of exercise or physical activity.

According to Roja, the meal was designed to be part of the daily ration package used by the Brazilian Air Force, provided with breakfast, lunch, dinner and supper, in order to guarantee quality, safety and facilitate storage and transport. It contributes to improving the hot meal offered in this kit and which constitutes its main dish. The major also considers that the menu could be produced to serve camps, excursions and the like, as it can be kept for up to two years without refrigeration.

Regional menus – The process studied, according to the researcher, provides parameters so that the Armed Forces can in the future order on the market, or even produce, higher quality operational rations and opens up space for national companies to export meals for civil or military use. Based on the results, he says, different menus can be developed to meet regional eating habits. To do this, simply evaluate the sterilization conditions for each menu and the sterilized flexible structures.

According to Professor Carlos Anjos, in a sterilized flexible packaging, in the form of an envelope, heat transfer is facilitated and heating can be done using a chemical heater, important in military exercises. “The opening can be done with your hands and the packaging can be used to store a wide range of foods.”

The result led the Air Force Command and the Army to place orders for operational rations prepared using the developed process. The Navy, also motivated by the work, and which imports food from the USA, will now buy it in Brazil, says Major Roja enthusiastically, who outlines the main advantages arising from the process: “We have eliminated the can; we improve product quality; we reduce the heating time in the autoclave, ensuring the integrity of the ingredients; we facilitate heating during consumption; we guarantee conservation at room temperature for up to two years; and, finally, we use packaging that facilitates automated filling and closing, which is easier to dispose of and which can be used during the meal, without the need for a lunch box or plate.”

Carlos Anjos was invited by the Air Force Command to participate in a defense conference that will take place at the end of March in Santiago, Chile, for an exhibition on the production of operational rations. The professor states that this could generate business for Brazil, since there are interests from neighboring countries in the technology developed and adapted.

The package - Roja recalls that in the 60s the American armed forces used the concept of sterilizable flexible packaging, retort pouch, as an alternative to the traditional tinplate can, which has proven reliability. In the 70s, flexible packaging became popular mainly thanks to research led by Japan and the USA.

O retort pouch, which in his opinion is perhaps the most significant development in packaging since the use of tinplate cans, is basically made up of three materials: an external layer of poly (ethylene terephthalate) film, responsible for resistance; a second layer of aluminum foil, which constitutes a barrier to gases, vapors, aromas and radiation; and internally, made of a polypropylene film, which enables heat sealing and prevents the product from coming into contact with aluminum.