First, the development history of military food
1. Definition of military food: the general name of all kinds of standard foods produced and supplied according to the technical standards stipulated by the army. This concept tells us that both military provisions and military provisions have specific technical and tactical requirements. For example, it requires small size, light weight, convenient carrying and eating, and reasonable nutritional structure; Good palatability; Easy to digest and absorb: safe and hygienic; Storage resistance. It can be quantified here, for example, the weight of each meal should be less than 1000 grams, and it should be stored for more than 2 years, so it can be eaten in the wild environment.
The military food of China People's Liberation Army can be divided into four categories: war food, voyage food, life-saving food and general food. As the name implies, military food has different requirements on different occasions. The product forms of military food mainly include dehydrated food and canned food. At present, some foods with moderate moisture content have improved their shelf life through fence technology and packaging technology, and began to enter the field of military food.
2. Definition of military food research: scientific research activities to develop and improve military food. This is an integral part of military research. Its main task is to develop convenient, delicious, safe, hygienic and nutritious standard food for all kinds of soldiers in war environment or under extraordinary circumstances by scientific methods.
The research on military provisions can be traced back to 1790. At that time, the French army led by Napoleon often fought far from home, and the long front made the contradiction of food supply prominent, and the food deteriorated before it reached the front. Therefore, the French army set up a military food research committee, including Gay-Lussac and other scientists. 18 10, the method of canning food invented by N. Appel of France is an important achievement of early military food research. In the following 100 years, the development of food science and nutrition and the discovery of vitamins laid a theoretical foundation for military food research. During World War II, the food research of the US military embarked on serialization. For example, research on general, special and life-saving foods should be carried out in different combat environments; The research on individual and collective food should be carried out according to the different number of suppliers. During the period of 194 1 ~ 1945, the U.S. military developed 23 kinds of food, among which the more famous ones were D rations for emergency use, C rations and K rations for paratroopers and tank soldiers. 1957 The US military began to study the replacement of tinplate packaging materials with soft packaging. 1978 successfully developed retort pouch which can store food for a long time, which is a breakthrough in packaging materials and packaging technology of military food research. Starting from 1978, the U.S. Army began to develop military food that can be easily heated under mobile combat conditions, in order to ensure the need of hot food in the battlefield. 1982, a new generation of collective rations T- 1 was successfully developed. After 1988, the U.S. military began to study military food under the operational conditions of 2 1 century, focusing on the development of military food with high calorie density, optimal nutritional composition, continuous consumption and modular composition.
From the development history of military food, canning technology was born for military needs. In this process, packaging developed from glass bottles and tinplates to soft packaging, which was first used in the military and then gradually turned into civilian products.
3. The main content of military food research
Military food processing. Including research to determine the required raw and auxiliary materials, containers, production processes (including canning, drying, irradiation, compression, vacuum infiltration, etc.). ), processing technology and anti-corrosion and anti-oxidation technology. To study the nutritional needs and health care needs of different people in different environments. Including the combination of food nutrition such as dietary spectrum, diet and daily diet.
Packaging materials and technology of military food. The packaging of military food should meet the requirements of storage, carrying and transportation. Packaging materials should be able to resist tearing, embrittlement and impact; Puncture and friction resistance, high temperature or low temperature resistance; Waterproof, vapor-proof and gas-proof; It can prevent mildew, insects and rancidity of oil, and can meet the needs of airdropping and floating; It can prevent the damage of neutrons and chemical reagents. At present, tinplate, plastic film and multilayer composite film are widely used.
Changes of military food during storage and transportation.
Military food additives. Comprises antioxidants, preservatives, mildewproof agents, bioactive substances and flavor substances.
Characteristics of military food. Including sensory acceptability, nutritional function, carrying and transportation. For example, military food usually takes daily or meals as the basic unit, and provides heat energy according to the dietary needs of various combatants in different combat environments, emphasizing the balance of nutrients such as protein, fat, carbohydrates and vitamins. On some occasions, military food is required to have anti-fatigue, anti-hypoxia, anti-cold, anti-radiation, fat mobilization and physical strength.
Identification method of quality and function of military food. Include physical, chemical and sensory evaluation methods.
4. Characteristics of military food research
Attach importance to military interests. In order to achieve the performance, technology and tactical indicators of military food, various technologies and processes should be comprehensively applied in the research of military food. For example, the compression technology that is convenient for military food to carry; Canning technology, drying technology, irradiation technology and vacuum infiltration technology for military food processing; Anti-corrosion, anti-oxidation technology and packaging technology for improving storage resistance; Self-heating technology and technology of adding bioactive substances to improve acceptability.
Pay attention to balanced nutrition. Generally speaking, military food includes daily portions or meals. It is not only a simple food to satisfy hunger, but also a necessity for soldiers to survive and maintain their physical strength in a fighting environment. Nutrition should be rich and comprehensive, prevent vitamin deficiency, and maintain the physical strength and energy of all kinds of combatants.
Second, a brief history of our army's field food development
1. stage1(1949 ~1976)
Before 1949, the China People's Liberation Army had no standard rations. After liberation, military food was developed and supplied during the War to Resist US Aggression and Aid Korea. Limited by the conditions at that time, the developed varieties were few, the taste was single, it was not resistant to storage and was easy to deteriorate. Institute of Health and Nutrition, Academy of Military Medical Sciences, 1953 studied cooked rice and instant noodles: supplied canned non-staple food: 1958 The General Logistics Department and Shanghai Food Industry Research Institute jointly developed compressed sweet and salty biscuits, miscellaneous grains biscuits, compressed broad bean cakes and corn lamb.
During the period of aiding Vietnam to resist America, 70 1 and 702 compressed dry food were developed.
The main results of this stage are 70 1 and 702 compressed dry food. Because it is a dry product, it adopts iron drum, embedded cover, nitrogen filling and tin welding. Canned food is mainly canned hard canned food.
2. The second stage (1976 ~ 1982)
From 1976 to 1982, our army developed a new type of food consisting of three staple foods (76 1 compressed dry food, dehydrated noodles, and dehydrated rice) and three non-staple foods (canned lunch meat, canned mixed fried meat, and canned diced meat with sauce), and named this as the first generation of field food.
The main characteristics of this stage of research are as follows: the military food began to consider the combination of staple food and non-staple food, but no dinner was formed. Dehydrated rice and noodles were not equipped with troops because of technical problems. There is no big breakthrough in packaging at this stage, and the packaging materials at 1 stage are basically introduced.
3. The third stage (1983 ~ 1994)
From 1983 to 1986, our army began to develop the second generation of field food. It consists of ordinary personal food, ordinary collective food, frontier patrol food and tank soldier food. Due to the limitations of some conditions at that time, no equipment was finally developed.
Eighty-six years later, our hospital developed special food (86 1 individual rations) for frontier patrol of plateau troops, scout food, Lu Qin series field food, 90 compressed dry food, 94 dehydrated rice and canned military vegetables. Among them, dehydrated rice, Lu Qin series field food and 90 kinds of compressed dry food were used respectively.
The main characteristics of this stage are: meals, eclipses, individual food and collective food; In nutrition, the calorie index and nutrition ratio index are put forward; At the same time, the navy and air force also developed voyage food, life-saving food and airborne food. At this stage, soft packaging materials are used for canned packaging, and multilayer composite materials with barrier properties are used to store dry products, such as dehydrated rice. Due to the particularity of the production technology of soft cans, there are some problems in the production process, such as pollution at the seal, high breakage rate, and some problems in the selection of varieties.
4. The fourth stage (1995 ~)
Our army has carried out research on high-energy field food, cross-sea landing food, plateau and mountain field food and a new generation of field food based on three series of staple food, non-staple food and soup and beverage.
For the first time, functional substances were used in high-energy field food, and self-heating devices were used in cross-sea field food for the first time. Straight nutritious instant noodles have achieved a breakthrough in the past 40 years, which can be rehydrated by cold water, hot water and boiled water. Not long ago, four items of staple food series, non-staple food series, soup and beverage series and canned rice porridge passed the technical appraisal passed by the Military Supplies Department of the General Logistics Department, and a number of high-level products appeared. These projects have made great breakthroughs in the corresponding technical fields and reached the domestic leading level. At the same time, the development of our army's self-heater has made a great breakthrough, and the heating efficiency has reached the technical level of the US military in the 1990s.
The characteristics of this stage: the research of high calorie density, modularization and functional field food was carried out; Research on self-heating field food was carried out; First, study the basic varieties, and then combine the series, menu and hot food to improve the comprehensive support ability of our army's field food. This stage is under way and will be completed around 2004. At present, in terms of packaging technology, the production technology of soft canned food has been improved, and it has been widely used in various wild foods as a basic variety; A number of aluminum-plastic tanks were tried, but when they were used in plateau, they encountered the problem of physical tank expansion, which restricted their use in the army. Easy to open cans into military food, solving the long-standing problem that canned food tastes delicious, but it is not easy to open; Some composite packaging materials have been widely used in military food, such as insulation materials used in self-heating cans, rehydration boxes used in dehydrated rice and noodles, and some tableware. In order to meet the needs of floating and airdropping, glass wool and foaming materials are used.
Third, the development trend of military food packaging
1. Canned food is the main variety of military food. Canned food can be stored for a long time at room temperature and has strong resistance to external adverse conditions. At present, the canned food market is depressed, and the army still has a soft spot for it. Canned packaging can be divided into soft packaging, hard packaging and semi-hard packaging in between according to its hardness. Judging from the development trend, these three kinds of packaging have development prospects in the military.
① Hard packaging
Military food is developed from hard packaging cans. The most important advantage of hard cans is their strong resistance to unfavorable external conditions. For example, rats can do nothing about hard cans, which have low external packaging requirements and strong impact resistance during storage and transportation.
Judging from the current situation of the army, hard cans are mainly used in collective food or general food in field food. The future development trend of military hard canned packaging is as follows:
A. easy to open the lid: as mentioned above, hard cans have the disadvantage of being difficult to open. In recent years, a number of easy-to-open military foods have been introduced, such as 962 cans with a diameter of 90 mm and eight-treasure porridge cans with smaller caliber. But this can't meet the requirements of military cans. Because the most commonly used military tank is 1068 tank with a diameter of100 mm. Due to technical reasons, it is not enough to open the lid with such a large caliber in China. In addition, the easy-to-open lid also has some technical problems, such as the easy-to-break pull ring, different nicks and so on. Therefore, the research on easy-to-open hard cans is one of the main development directions of military cans in the future.
B. shaped canned food: the U.S. army's T-shaped ration is actually a rectangular flat canned food made of chrome-plated tinplate. It contains 3 kilograms of food. T-ration is actually a two-piece jar, consisting of a bottom and a lid. This kind of pot can be used as a pot, can be placed on a fire, or can be placed on a steam table for heating and insulation. It can also be used as tableware instead of dishes, which improves the convenience of military food. At the same time, it is a storage container. At present, China does not have the ability to produce such large rectangular cans. The technical difficulty mainly lies in the high rejection rate when sealing, which leads to high production cost and can not be applied.
C. coating: the shelf life of military cans is more than 3 years. In addition, the coating is required to have sulfur resistance and acid resistance. At present, some military cans often rust.
② Flexible packaging
Soft-packed cans are developed on the basis of hard cans. The main problem of soft packaging is its poor tolerance to external adverse conditions, and its sealing performance is more fragile than that of hard cans. The wrinkle resistance of aluminum foil packaging is poor, and when the vacuum is high, the folds produced by the bag are easy to produce pinholes. In addition, rat prevention is also an important issue.
According to the current situation of the army, canned soft packaging is mainly used for individual food in field food. If the technology is improved, it may also be used for collective food. In the future, soft can packaging will develop in the following directions:
A. aluminum foil bag: aluminum foil has good gas barrier and light barrier. However, the wrinkle resistance is poor, and the aluminum foil is prone to fracture in the case of wrinkling. Improving wrinkle resistance by compounding with other materials is a direction of future research.
B. Composite material: a new type of soft packaging bag composed of high resistance, puncture resistance and high temperature resistance materials. This kind of bag has an outstanding advantage over aluminum foil bag, that is, it can be heated by microwave, but its shading performance is poor, so some measures need to be taken to make up for it.
C. Heat sealing layer: In the production of soft cans, if the bag mouth is polluted, such as oil, the sealing may be loose or the strength may be reduced, which has a great impact on the production speed and product quality.
At present, relevant experts are exploring the use of a new type of heat sealing layer, which still has good sealing strength under the condition of being polluted by oil pollution. The breakthrough of this technology will have a great impact on flexible packaging technology.
D. Rat prevention: It often happens that soft packaging cans are bitten by rats. Especially in combat conditions, field food stored in simple field warehouses is even more so. This situation seriously limits the use of soft cans. In the future, this problem will be solved either by the strength of packaging materials or by adding unpleasant smell to mice in packaging materials.
E. Natural degradation: In view of the requirements of environmental protection, develop flexible packaging materials that can be naturally degraded.
③ Semi-hard packaging
Semi-rigid packaging is a new type of canned packaging material. Because it is between hard tank and soft tank, it takes into account some advantages of both. Especially in opening the lid, it is better than hard and soft cans. Developing new semi-hard canned materials will be one of the development directions of military canned food in the future.
A. Aluminum-plastic packaging: some field food for foreign troops. If sauce, cream and some condiments. Aluminum-plastic canned food is a kind of canned food with gas. Because of China's vast territory and considerable plateau, canned food with gas will produce physical obesity at high altitude. In order to use aluminum-plastic cans in our army, we must solve this problem in order to have a bright future.
B * * * extrusion packaging of multilayer materials: this material takes EVOH as the barrier material and can withstand the high temperature of 12 1℃. Because the plastic has good formability, it is easy to be made into a grid shape, and the top is heat-sealed with plastic composite materials. In this way, there can be several kinds of rice in a box. This is difficult for metal cans to do. Domestic enterprises have tried this kind of packaging material, and we are going to carry out experimental research in this field in the future. This kind of packaging should be the most promising. But also has good development value in the civil market.
2. Packaging of dried products
Dry products can be stored at room temperature, so many military foods adopt this form. The packaging materials of our dry goods are widely used, such as tinplate, aluminum foil and composite packaging materials.
① Oxygen-proof packaging
Most military dry food contains oil, and some of them are still relatively high, such as compressed dry food. The most critical factor affecting the shelf life of this kind of food is fat oxidation. Therefore, the packaging of such products must have good oxygen barrier performance. According to the current development of packaging, tinplate, aluminum foil packaging bags and multi-layer composite bags will be widely used in military food. In particular, some dry goods, such as dehydrated rice, have low oil content, but they are also very easy to produce spicy taste. The packaging requirements of this product are the same as those of high-fat products.
② Waterproof and vapor-proof packaging.
Some dried products have good storage characteristics, such as dehydrated noodles. As long as it can prevent moisture absorption, this product can be stored for a long time. Therefore, the packaging materials used in this kind of products are relatively simple and the price is relatively cheap.
3. Edible packaging
Some advanced foreign troops are studying edible packaging. This kind of packaging is often used for inner packaging. On the one hand, it can reduce the volume and quality of packaging and increase the edible part of the whole set of food. On the other hand, it can improve the convenience of use and reduce food pollution and slag drop. At present, there is little research on edible packaging in our army, but it will be a promising research content.
4. Combined packaging
Military food usually consists of a variety of products. If there is canned food, compressed dry food, seasoning and the like. When these products are combined into dietary food or daily food according to certain nutritional ingredients, the packaging used is combined packaging. According to different occasions, the materials used in combined packaging are also different. At present, the materials used for combined packaging are cartons, composite bags, plastic boxes, tinplates and so on. On the premise of providing protective performance, the most important principle of these materials is to reduce weight and price.
5. Protective packaging
There is an increasing demand for military food in modern wars. Because of the rapidity and maneuverability of the war, it is required that military food can withstand airdrops and parachutes, float on the water, and prevent damage and pollution caused by various nuclear weapons explosions. At present, foam plastics and glass wool are used as protective packaging.
These two materials can not only float on the water, but also cushion the impact caused by airdrops. The research in this field needs to be further strengthened.
6. Heat preservation and packaging
In order to improve the sensory acceptability of military food, the army developed a self-heating flameless heater. This heater can heat the central temperature of canned food to about 60℃. In order to effectively improve the efficiency of the heating sheet, prevent heat loss and prevent the skin from being scalded by excessive temperature, heat insulation materials are needed. This packaging material requires small volume and good heat insulation effect.
7. Outer packaging
Cartons are now used for the outer packaging of military food. It is expected that it may be combined with protective packaging to produce cardboard and plastic composite packaging in the future.
Generally speaking, military food packaging will develop in the direction of light weight, reliability, increased function and biodegradability.