DNA RNA test rt-pcr kit ,magnetic beads pcr,acid extraction kit,nucleic extraction kit Shenzhen Uni-medica Technology Co.,Ltd , https://www.uni-medica.com
The military food of the Chinese People's Liberation Army is divided into four categories: field food, voyage food, life-saving food and general food. As the name implies, military foods vary in their requirements depending on the occasion. The products of military food mainly include dehydrated foods and canned foods. At present, some medium-moist foods have improved their shelf life by fence technology and packaging technology, and they have begun to enter the military food field.
2. Military food research definition: research and improve the research activities of military food. It is an integral part of military research. Its main task is to scientifically develop all kinds of foods that are suitable for the delicious, safe, healthy and nutritious foods that military personnel need in war environment or in extreme circumstances.
Military food research dates back to 1790. At that time, France* was often away from the local warfare under the leadership of Napoleon. The long line of war provided a contradiction in supply and supply, and the food had not deteriorated on the front line. To this end, France* was established to J. -L. Covering a Luisac and other scientists as members of the Military Food Research Committee. In 1810, France N. The food canning method invented by Abel is an important achievement in the early military food research. Since then, more than 100 years, the development of food science, nutrition, and the discovery of vitamins have laid a theoretical foundation for military food research. During the Second World War, the US military food research went on serialization. For example, research on general, special, and life-saving foods is conducted according to the operational environment: individual and collective food research is conducted according to the number of people supplied. From 1941 to 1945, the US military developed 23 kinds of foods, among which the well-known D-food block, C-ration and K-ration for paratroopers and tank soldiers. In 1957, the US military began research on the replacement of tinplate packaging materials with flexible packaging. In 1978, it successfully developed a retort pouch that can store food for a long time. This is a breakthrough in packaging materials and packaging technology for military food research. In 1978, the US military food research began with the need to secure hot food on the battlefield, and began to develop military foods that could be easily heated under mobile combat conditions. In 1982, a new generation of collective rations was developed. After 1988, the US military set out to conduct military food research under the 21st century combat conditions, focusing on the development of military foods with high caloric density, zui good nutritional composition, continuous consumption and modular composition.
From the history of military food development, tank technology was born out of military needs. In this process, the development process of packaging from glass bottles, tinplate to flexible packaging is first used for *, 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 tanking, drying, irradiation, compression, vacuum infiltration, etc.) processing technology and anti-corrosion, anti-oxidation technology military food nutritional characteristics and functions. Study the nutritional needs and health needs of all types of people in different environments. Includes nutrients for combination foods such as meal, meal and day.
Military food packaging materials and packaging processes. The packaging of military foods should meet the requirements for storage, carrying and transportation. Packaging materials should be resistant to tearing, cracking, impact resistance; resistance to puncture, abrasion, high temperature or low temperature; block water, water vapor and gas; can prevent mildew, insects, oil rancid, can adapt to airdrop and float Need; can prevent neutron damage, chemical agents. At present, there are many tinplates, plastic films, multilayer composite films and the like.
Changes in military food during storage and transportation.
Military food additives. Including antioxidants, preservatives, anti-fungal agents, bioactive substances, flavor substances.
Special properties of military food. Including sensory acceptability, nutritional function, carrying and transporting properties. For example, military foods usually use daily or meal as the basic unit to provide 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. In some cases, military foods are required to have anti-fatigue, anti-hypoxia, anti-cold, anti-radiation and mobilize fat, and enhance physical fitness.
A method for identifying the quality and function of military food. Includes methods such as physical, chemical, and sensory evaluation.
4. Characteristics of military food research: attach importance to military benefits. In order to achieve the performance, technical and tactical indicators of military food, military food research should use a variety of processes and technologies. Such as the compression technology for military foods; the canning technology for military food processing, drying technology, irradiation technology, vacuum infiltration technology, etc.; anti-corrosion, anti-oxidation technology and packaging technology used to improve storage resistance; Self-heating technology and technology for adding biologically active substances.
Pay attention to the nutritional balance. Military foods generally consist of daily units or meals. It is not only a simple hunger, but also a necessity for military personnel to survive and maintain physical strength in a combat environment. It should be able to solve the problem of nutrition and acceptability of its survivors for a long time. It should be nutritious and comprehensive. It can prevent vitamin deficiency and maintain the physical strength and energy of all kinds of combatants.
Second, a brief history of the development of our military field food 1. Phase 1 (1949-1976)
Before 1949, the Chinese People's Liberation Army did not have standard military food. After the liberation, military food development began, and supply began during the period of the War to Resist US Aggression and Aid Korea. Limited to the conditions at that time, the variety developed was small, the taste was simple, it was not resistant to storage, and it was easy to deteriorate. Institute of Health and Nutrition, Academy of Military Medical Sciences, 1953, researched fast-cooked rice and instant noodle: supplied canned food canned food: 1958, together with Shanghai Food Industry Research Institute, jointly developed compressed sweet and salty biscuits, multigrain biscuits, compressed broad bean cake, corn Five kinds of dry food such as lamb.
During the period of aiding the United States, 701, 702 compressed dry food was developed.
The main results of this phase of research are 701, 702 compressed dry food. Because it is a dry product, it is made of iron drum, embedded cover, nitrogen and tin welding. The cans are mainly tin cans of tinplate.
2. Phase 2 (1976-1982)
From 1976 to 1982, our army developed a new type of food consisting of three staple foods (761 compressed dry food, dehydrated noodles, dehydrated rice) and three non-staple foods (canned luncheon meat, canned assorted canned food, canned diced pork). Name this as *generation field food.
The main features of this phase of the study: military food began to consider the main and non-staple food mix, but did not form a meal. Dehydrated rice and dehydrated noodles are not equipped* due to technical problems. There was no major breakthrough at this stage of packaging, and the packaging materials were basically introduced along the first stage.
3. Phase 3 (1983-1994)
From 1983 to 1986, our army began to develop second-generation field food. It consists of ordinary individual food, general collective food, border patrol food and tank food. Due to some restrictions at the time, Zui did not develop equipment.
After 86 years, we carried out the development of plateau* border defense patrol special food (861 individual rations), scout food, Luqin series field food, 90 compressed dry food, 94 dehydrated rice, and military vegetable canned food. Among them, dehydrated rice, Luqin series field food, and 90 compressed dry food were respectively applied.
The main features of this stage are: composition of the form of food, daily food, individual food and collective food; the introduction of thermal indicators and nutrient ratio indicators; at the same time, *, * also developed Voyage food, life-saving food and airborne food. At this stage, canned packaging uses flexible packaging materials, dry product storage, such as dehydrated rice storage using a multilayer composite with barrier properties. Due to the particularity of the production technology of soft cans, there are problems such as pollution at the seal and high damage rate during the production process, and some problems have appeared in the selected varieties.
4. Stage 4 (1995~)
Our army has carried out research on high-energy field rations, cross-sea landing combat foods, plateau mountain field foods, and a new generation of field foods based on three major series of staple foods, non-staple foods and soup drinks.
High-energy field rations used functional substances for the first time in field foods. For the first time, the use of self-heating devices for cross-sea landing field foods, the direct-type nutritious instant noodles achieved a breakthrough in 40 years, it can be re-watered in cold water, also in hot water. Rehydrated, but also boiled. Not long ago, the four items of the staple food series, the non-staple food series, the soup drink series and the rice porridge can pass the technical appraisal passed by the General Military Department, and a number of high-level products appeared. These projects were obtained in the corresponding technical fields. A major breakthrough has reached the domestic level of ling. At the same time, our military's self-heater development has made a big breakthrough, and the heat efficiency has reached the technical level of the US military in the 1990s.
Characteristics of this stage: research on high-calorie density, modularity and functional field foods; research on self-heating field foods; research on basic varieties, followed by serialization and meal-making The research on hot foodized field foods will improve the comprehensive support ability of our army field food. This phase is underway and will be completed in about 2004. At this stage, in the packaging technology, the soft can production technology has been improved. As a basic variety, it is used in a large number of field foods. A batch of aluminum-plastic cans has been tried. When it is used in the plateau, it has encountered the problem of physical ups and downs. In the use of *; easy to open cans into military food, to solve the long-standing problem of "canned food is difficult to open"; some composite packaging materials in the military foods are used in a large number of applications, such as self-heating cans The insulation material, the dehydrated rice, the rehydration box used for the dehydrated noodles, and some tableware, etc.; in order to meet the needs of floating, airdrop, etc., glass wool, foaming materials, etc. are used.
Third, the trend of military food packaging development 1. Canned canned food is a common breed of military food. Canned food can be stored at room temperature for a long time, and has strong ability to withstand adverse external conditions. In the current sluggish canned food market, * still has a soft spot for it. Canned packaging is divided into flexible packaging, hard packaging and semi-rigid packaging in between depending on its hardness. From the perspective of development trends, these three kinds of packaging have development prospects in military use.
1 Hard-packaged military foods have been developed from hard-packed cans. The ability of hard cans to withstand adverse external conditions is an important advantage of hard cans. For example, rats have no way to hard cans, hard cans have lower requirements for external packaging, and are resistant to impact during storage and transportation.
Hard cans are mainly used in group foods in field foods according to the current situation of *, or used in general foods. The development trend of hard canned packaging in military use in the future is as follows:
a. Easy open cover: As mentioned before, hard cans have the disadvantage of opening difficulties. In recent years, a number of easy-open lids have been introduced into military foods, such as the 962 cans with a diameter of 90 mm and the eight-treasure porridge cans with a smaller diameter. But this does not meet the requirements of military cans. Because the military cans use more than 1068 cans with a diameter of 100 mm. Due to technical reasons, such a large-caliber easy-open cover is still not enough in China. In addition, the easy-open cover also has technical problems such as easy breakage of the pull ring and uneven depth of the scribe line. Therefore, the study of easy-opening hard cans is one of the main directions for the development of military cans in the future.
b. Shaped cans: The US military's T ration is actually a rectangular flat can, which is made of chrome-plated tinplate. The food is 3 kg. The T ration is actually a two-piece can consisting of a bottom and a lid. The can can be used as a cookware, can be placed on a fire or placed on a steam table to heat and keep warm; or can be used as a tableware instead of a dish bowl to improve the ease of use of military food. At the same time, it is also a storage container. At present, China does not have the ability to produce such large rectangular cans. Its technical difficulty is mainly due to the high scrap rate when sealing, which leads to high production cost and cannot be applied.
c. Coating: Military cans have a shelf life of more than 3 years. Moreover, coatings having sulfur and acid resistance are required. At present, some military cans often have rusting of the can body.
2 Flexible packaging cans of soft packaging have been developed on the basis of hard cans. The main problem with flexible packaging is the ability to withstand poor external conditions, and the sealability is more susceptible to damage than hard cans. The foil packaging has a poor ability to resist wrinkles, and when the degree of vacuum is large, wrinkles generated in the bag are liable to cause pinholes. In addition, anti-rat is also an important issue.
Soft-pack cans are mainly used in individual foods in field foods according to the current situation. If it is technically improved, it may also be used for collective food. Soft can packaging will develop in the following directions:
a. Aluminum foil bag: Aluminum foil has good barrier properties, including gas and light. However, the anti-wrinkle ability is poor, and in the case of wrinkles, the aluminum foil is prone to breakage and the like. Improving the anti-wrinkle performance by compounding with other materials is a direction for future research.
b. Composite material: A new flexible packaging bag is produced by compounding materials with high barrier properties, puncture resistance and high temperature resistance. This bag has an outstanding advantage over the aluminum foil bag, which can be heated in the microwave, but its shading is poor, and some measures need to be taken to make up.
c. Heat sealing layer: In the production of soft can, if the bag mouth is contaminated, such as oil stains, it may not be tight when sealing, or the strength is reduced. This problem has a great impact on the production speed and has an impact on product quality.
At present, experts are exploring the use of new heat sealing layers, which still have good sealing strength in the case of oil pollution. This technological breakthrough will have a major impact on flexible packaging technology.
d. Anti-rat: It is common for soft-packed cans to be bitten by mice. Especially in combat conditions, this is especially true for field foods stored in simple field warehouses. This situation severely limits the use of soft cans. This problem will be solved in the future by the strength of the packaging material or by adding the unpleasant odor to the packaging material.
e. Natural degradation: In view of environmental requirements, development can naturally degrade flexible packaging materials.
3 semi-rigid packaging Semi-rigid packaging is a new type of canning material. Because it is between hard cans and soft cans, it takes advantage of both. Especially in terms of opening, it is better than hard and soft cans. The development of new semi-hard canned materials will be one of the future directions for the development of military cans.
a. Aluminum-plastic packaging: used in some field foods of the foreign army. If sauce, cream and some condiments. Aluminum-plastic cans are a kind of gas-filled cans. Due to the vast territory of China, there is a large plateau. Gas-filled cans will produce physical fatness at high altitudes. In order for aluminum-plastic cans to be used in our military, it is necessary to solve this problem.
b. Co-extruded packaging of multi-layer materials: This material uses EVOH as a barrier material and can withstand temperatures up to 121 °C. Since the plastic has good molding properties, it is easy to be formed into a grid shape, and the top is heat-sealed with a plastic composite material. Thus, there are several types of meals in a box. This is hard to do with metal cans. Domestic enterprises have tried out this kind of packaging materials, and we are going to carry out experimental research in this area in the future. This kind of packaging should be promising for Zui. Moreover, it will have good development value in the civilian market.
2. Dried product packaging is resistant to storage at room temperature, so many military foods use this form. Our military dry product packaging uses a wide range of materials, such as tinplate, aluminum foil and composite packaging materials.
1 Oxygen-packaging military dry foods mostly contain oil, some of which are relatively high, such as compressed dry food. The key factor affecting the shelf life of such foods is fat oxidation. Therefore, such products must use a package with good oxygen barrier properties. According to the current development of packaging, like tinplate, aluminum foil bags, multi-layer composite bags will be used in military food. In particular, some dry products, like dehydrated rice, have a low oil content, but they are also very susceptible to halo. The packaging requirements for this product are the same as for high fat products.
2 Water and steam packaging Some dry products have good storage properties, such as dehydrated noodles. This product can be stored for a long time as long as it prevents absorption of moisture. Therefore, the packaging materials used in these products are relatively simple and the price is relatively cheap.
3. Edible packaging Some advanced foreign forces are studying edible packaging. This type of packaging is often used for inner packaging. On the one hand, it can reduce the volume and quality of the package, increase the edible portion of the whole set of food, and on the other hand, it can improve the convenience of use, reduce the contamination of food, and reduce slag. At present, our army has less research on edible packaging, but this will be a promising research content.
4. Combined packaging of military foods is usually a combination of multiple products. If there are canned foods, there are compressed dry foods and seasonings. The packaging used when these products are combined into a meal or a daily food according to certain nutrients is a combination package. The materials used in the combination package are different depending on the application. At present, materials used for combination packaging include cartons, composite bags, plastic boxes, tinplate, and the like. Under the premise of providing protective performance, these materials are important in reducing weight and reducing price.
5. Protective packaging Modern warfare demands for military foods continue to increase. Due to the rapidity and maneuverability of the war, military foods can withstand airdrops and umbrellas, can float on the water, and can prevent damage and pollution caused by explosions of various nuclear weapons. Currently, it is used as a protective packaging for foam, glass wool, and the like.
These two materials can float on the water surface and better cushion the impact generated by airdrops. Research in this area has yet to be further strengthened.
6. Insulation packaging In order to improve the sensory acceptance of military foods, * a self-heating flameless heater was developed. This heater heats the temperature of the canned food center to around 60 °C. In order to effectively improve the efficiency of the heating sheet, prevent heat loss, and prevent the temperature from being too high to burn the skin, an insulating material is required. This packaging material requires a small volume and a good heat insulation effect.
7. Outer packaging military food packaging is now using cardboard boxes. It is expected that in the future it will be combined with protective packaging to produce a composite of cardboard and plastic composite. In summary, military food packaging will be lighter, can be *, increased functionality, biodegradation and other directions.
Analysis on the development trend of military food packaging in China
Foodjx Guide : First, the history of military food development 1. Military food definition: The general term for all kinds of foods produced and supplied according to the technical standards stipulated by *. This concept tells us that food that is not eaten is military food, and it has specific technical and tactical requirements. For example, it requires small volume, light weight, convenient to carry and eat: reasonable nutritional structure; good palatability; easy to digest and absorb: safe and hygienic; Here we can quantify, if the weight requirement is less than 1000 grams per meal, the storage requirement is more than 2 years, and it can be ready to eat in the wild environment.
Prev Article
How Hawthorn Frozen Processing