In recent years, consumers have become increasingly demanding food quality, food safety, flavor, nutritional value, has become the main basis for consumers to buy food. For this reason, many of the food production enterprises, are doing everything possible from the safety, flavor, nutritional value, etc. to improve food quality, in order to attract more consumers. Traditional sterilization methods, and some require a larger investment, and some use of high cost, making it difficult to meet the food production needs. The microwave sterilization With better able to keep the nutrients in food ingredients, does not destroy the flavor of the product, energy saving, convenient operation, has drawn increasing attention to food production enterprises. However, many food companies in the use of microwave sterilization process, the effect of microwave sterilization and stability of a variety of opinions and questions, and some reflect the bactericidal effect is not satisfactory preservation, sterilization and some reflect poor stability, not easy control. To solve these problems, this reporter recently interviewed the famous food preservation and microwave sterilization expert Professor Wu Yongnian. Professor Wu Yongnian livestock products is China Research Society Preservation Committee vice chairman, the national invention patent technology "low-temperature microwave sterilization integrated preservation technology," the owner.

    Microwave sterilization sterilization sterilization is not complete fresh concept to distinguish

    Reporter: You can microwave sterilization, it is well known the truth, but some users are reflected microwave equipment "Certain foods using microwave sterilization, the deterioration phenomena still occur, and preservation of the effect is not ideal." Is this what reason?

    Wu Yongnian: To find out the reason, we must first find out sterilization, preservation, sterilization difference between a few terms. Strictly speaking, there is a difference between them.

    Very easy for many spoilage products, sterilization does not mean preservation, but the preservation of bactericidal or bacteriostatic must adopt measures. Food preservation is defined to take certain measures for food processing, the food at room temperature for a period of time, be able to maintain good quality. Quality, including freshness, flavor, total number of bacteria, nutrients and so on.

    Kill certain amount of bacteria, but not kill all the bacteria, this process is often referred to as sterilization. The sterilization, the sterilization rate may be 50%, it can be 80% or 95%. Will kill all the bacteria in food operation process, known as sterilization. Food just after microwave sterilization, its bacterial content will decline more or less, but some not kill microorganisms when the conditions are right, will still multiply, causing food spoilage. Cause microbial blooms suitable conditions include high moisture, high nutrients, higher temperatures. The preservation must ensure that there is a high sterilization rate, uniformity, and to take measures so that the remaining bacteria multiply within the warranty period will not be triggered by food spoilage.

    Some users complained that "microwave sterilization preservation ineffective", there may be several reasons: First, the sterilization rate is low, more viable residues in food; Second sterilization uneven; Third, the raw food materials of bacteria more. In general, a simple method using microwave sterilization of food, in the sterilization, the food would remain the more bacteria. In the process of food preservation, but also growth and reproduction, and cause food spoilage happen.

    Microwave sterilization how to ensure good results using a professional microwave sterilization equipment and processes

    Reporter: So, how can we ensure the preservation of microwave sterilization has a good effect it?

    Wu Yongnian: based on 10 years of research and application experience, we believe that to ensure the preservation effect of microwave sterilization, the first to use a professional microwave sterilization equipment. The so-called professional, referring to the sterilization equipment to ensure uniformity, and has insulation function, to ensure that food in vacuum-packed under atmospheric pressure to achieve sterilization temperature for a predetermined period of time heat sterilization without bulging bags. This professional equipment is best to install a computer-controlled facilities to eliminate human and environmental factors on the bactericidal effect. Second, to have a set of measures to reduce the degree of contamination of bacteria and other microorganisms to enhance microwave sterilization effect. Practice has proved that the application for different products, different production conditions, you must use different sterilization preservation methods. In the whole process of food production, preservation methods suitable sterilization is very important, in a suitable microwave equipment is determined, the sterilization process has become crucial to ensure bactericidal effect, it is like computer software in the computer, like the importance of.

    So far, some food as yet to find a suitable sterilization process, so in the microwave sterilization, sterilization effect is not ideal. In short, suitable for microwave devices and sterilization process, the key is to ensure that the bactericidal effect.

    To prevent bulging bags before sterilization packaging is apt to cause secondary pollution after

    Reporter: In the use of microwave sterilization process, in order to prevent the occurrence of bulging bags, some food companies using the first method of sterilization after packaging, and some joined in the sterilization chamber backpressure. These two methods are feasible? What do you think?

    Wu Yongnian: I do not agree with the above approach. Because, first sterilization repacking, will lead to secondary bacterial contamination in the packaging when problems arise. Some people think that can be sterilized for aseptic packaging, but the reality is that in the process of industrial production, it is difficult to achieve a purely aseptic packaging. Join backpressure sterilization, improved product sterilization temperature, therefore, to improve the bactericidal effect, it would also destroy a certain extent, the product color, smell, taste, shape, thus losing the "at lower temperatures to maintain product flavor unchanged "advantage.

    Scope of application of microwave sterilization of food six series of food has been widely used

    Reporter: I heard that you are in the field of microwave sterilization of food obtained national invention patents, equipment manufacturing, food preservation technology has made a series of achievements, and has been applied across the country, can you tell us about the situation in this regard?

    Wu Yongnian: As with non-thermal effects of microwave sterilization, sterilization temperature is lower, does not destroy the flavor of the product, etc. So, microwave sterilization is a promising method of sterilization, many people are studying abroad, the application of such sterilization equipment and technologies. However, the use of microwave sterilization, there are many factors of instability and defects, such as sterilization uneven, difficult to control; microwave sterilization in the food industry is able to gain large-scale application, the key lies in research departments and enterprises can maximize application reduce or avoid these drawbacks it to fully play its positive role, in a word is this: in the sterilization, the ability to be effective, stable and easy to control.

    I started from 1991 microwave sterilization technology research, the object of study is the beginning of the famous Nanjing specialty "Nanjing salted duck." According to the traditional method of production, packaging, Nanjing salted duck, its shelf life is only 15 days at room temperature, each for a longer shelf life is very difficult, and the operation is very troublesome. In view of this situation, I and Nanjing High-tech Development Co., Ltd. Yongqing a food, developed a series of microwave equipment suitable for food sterilization equipment many varieties, from mechanical control to full computer control has greatly improved microwave sterilization results. Meanwhile, also on the sterilization process, improve the bactericidal effect of assistive technology conducted in-depth research, so Nanjing salted duck extend the shelf life of 3 to 6 months, and found a number of ways to adjust shelf life.

    Currently, we have developed out of the microwave sterilization equipment and technology that can effectively sterilize the variety of food preservation has several series: First Chinese livestock and poultry cooked meat, including pork products, cattle and sheep products, cooked rabbit products, cooked fish products , cooked egg products, etc.; Second, a variety of Western cooked meat products, such as Western-style ham, bacon, barbecue, etc.; Third, various soy products; Fourth of Chinese dishes; Fifth snacks throughout; six is ​​all kinds of powdered food.

    Reporter: earlier successful use of microwave sterilization Nanjing High-tech Development Co., Ltd. Evergreen Foods, the current can produce special microwave sterilization equipment?

    Wu Yongnian: Nanjing Evergreen Foods Co., Ltd. is a specialized high-tech development of food preservation techniques and technology enterprises, research and development projects, including food corrosion, oxidation, mildew, pest control and so on. Meanwhile, the company has also developed and food preservation related ancillary equipment, all kinds of preservation agent. The company set up a special department, production of special microwave sterilization equipment, has extended to food companies across the country, from the practical point of view, most of them to achieve the desired requirements.

    Chinese cuisine can microwave preservation technology has matured has five advantages

    Reporter: You mentioned Chinese dishes microwave preservation technology is a kind of concept?

    Wu Yongnian: Chinese dishes microwave preservation technology is a newly developed technique. Chinese cuisine is eat in the restaurant in some dishes, such as braised pork, steamed fish, flowers Caichao meat, homemade tofu. Preservation technology using microwave sterilization process for Chinese dishes, with so few advantages: First, the original flavor of dishes can be kept unchanged; Second Chinese dishes can be stored at room temperature on a longer time; Third, it could be Chinese dishes directly into the supermarket sales; Fourth, the majority of consumers are not able to make into the restaurant, you can enjoy a range of delicious Chinese dishes; five for food production has opened up a new field.

    Microwave sterilization sterilization additives preservatives several auxiliary link is not free

    Reporter: I heard that you have developed a sterilizing agent, which is a kind of substance, it has what role?

    Wu Yongnian: So far, the number of high moisture, high protein foods, microwave sterilization alone, it is difficult at high temperatures, it will extend the shelf life of 6 months. Purpose, we developed a sterilizing agent, to enhance the sterilization effect. Such additives have bactericidal properties of such aspects: First safe. Its main ingredient is extracted from plants belonging to the pure natural substances and do not contain chemical preservatives, through state departments of toxicological experiments indicate that the product is a safe food processing aids. Second, this bactericidal additives on microwave sterilization has a strong synergistic effect. In addition, the use of such additives after sterilization, does not change the original flavor.

    Reporter: Some food companies in the use of microwave sterilization before, to add a certain amount of food preservatives, is this feasible?

    Wu Yongnian: To determine "whether to add preservatives in foods feasible", the key depends on two points: First, the state is allowed; Second is valid.

    In order to regulate the use of food additives, countries have developed GB2760 "food additives health standards." If they meet the standard requirements of the use of varieties, usage and scope of use, and belong to food grade additives can be used; otherwise it can not be used. While really effective, resulting in a waste of otherwise even pollution.

    Reporter: Some people reflected microwave sterilization of food after a long time after storage, there will be "rancid" taste. How to solve this problem?

    Wu Yongnian: Some foods rich in fats, oils after contact with oxygen will slowly be oxidized to produce rancid flavor. It can be said that this rancid flavor and microwave sterilization is not directly related; does not actually go through microwave sterilization of food, will also appear in the long-term storage after the rancid smell.

    To solve the problem is not complicated rancid taste, first of all, the material can be selected as less oxygen packaging containers, such as the use of nylon or polyester layer as a composite plastic packaging containers; Further, in the packaging containers can also be used oxygen agent. Of course, whether it is a good selection of packaging materials, or the use of oxygen scavengers, there is a problem of scientific use.

    Reporter: Some powdered foods such as chili powder, in the use of microwave sterilization process, there will be changes in sensory properties such as color and other issues, you can solve this problem?

    Wu Yongnian: be able to solve. This is indeed a challenge to chili powder, for example, due to its pre-processing of bacterial contamination is very serious, you want to conduct a thorough disinfection, sterilization temperature must be increased or prolonged sterilization time, and the temperature is too high and too long, chili powder will make the color change. It can be said, chili powder on the sterilization process is very strict. For nearly a year, we have developed specialized equipment and appropriate technology for powdered food sterilization, and achieved remarkable results, to solve a variety of powdered food color in the sterilization issue.

    Reporter: How do you intend to further promote integrated microwave sterilization temperature preservation technology?

    Wu Yongnian: Currently, many different types of food preservation technology. To promote our technology, we must provide good service. To promote advanced microwave sterilization technology, first of all, we will adopt a variety of measures, the majority of the food business advocacy definition and advantages of microwave sterilization; secondly, will provide customers with free technical advice, closer relations with customers; addition, we also established a laboratory, a number of food companies in our technology is not yet understood in doubt, for this part of the business, we can ask them to our bodies do free experiments, and other experimental results are satisfactory, the technical negotiations with these companies again Transfer thing.