Food Sterilization Technology from "hot Processing" to "cold Processing"

Food sterilization technology is one of the core technologies of the food industry. It is a technology that uses various means to kill all kinds of harmful microorganisms contaminated by food itself, brought into food packaging containers, introduced by operators and equipment in the process of processing and deployment, as well as existing in the production environment, so as to maintain food quality and reach a certain storage period. Sun Yunjin, associate professor of the College of Food Science and Engineering at Beijing University of Agriculture, has made a breakthrough in the application of plasma sterilization technology in agricultural production and food processing. The first super ion sterilization machine in Beijing University of Agriculture has been successfully tested in Beijing University of Agriculture. Sun Yunjin said that low temperature air plasma has the characteristics of killing microorganisms and decomposing organic matter, and has a good killing effect on a variety of microorganisms in different foods, and has the characteristics of high efficiency, fast, no residue, low temperature and wide application range, which is of great application value in the food industry.

The rise of non-hot food processing technology

In recent years, in order to maximize the nutritional value of food, the food industry is constantly seeking the development and application of new technology, using a series of non-thermal processing technology and equipment, in-depth study of food processing from the traditional. Hot working; To the ldquo; Cold working; Change and innovation, explore low temperature technology, in order to ensure product quality and safety, to achieve sustainable development of the industry.

With the improvement of living standards and the development of food processing industry, people pay attention to food safety at the same time, the requirement of food nutrition is also increasing. Conventional thermal sterilization technology will affect the nutritional and sensory quality of food, and may even produce acrylamide, furan and other toxic and harmful substances. Non-thermal sterilization technologies, such as ultra-high pressure, irradiation, ultrasonic, ultraviolet, ozone, low temperature plasma, avoid the limitation of thermal sterilization, and gradually attract people's attention. However, non-thermal sterilization techniques such as ultraviolet, ultrasonic, and ozone usually require treatment. It takes 60 minutes to effectively reduce the number of microorganisms, which consumes time and energy. However, ultra-high pressure sterilization can only use flexible packaging materials, which limits the form of packaging.

As a new non-hot food processing technology, low temperature plasma technology has great application potential in the field of food. Low temperature plasma is the energetic electrons, excited particles, active oxygen, active nitrogen and other active substances produced mainly by gas discharge under atmospheric pressure and ambient temperature. Low temperature plasma technology has a good killing effect on a variety of microorganisms in different foods. It has the characteristics of high efficiency, fast speed, no residue and low temperature. As an emerging cold sterilization technology, low temperature plasma has a killing effect on various pathogenic and spoiled microorganisms in food. The generated high-energy charged particles, active substances, ultraviolet light, etc., will destroy cell membranes, proteins, nucleic acids, enzymes and other macromolecular substances in microorganisms, thus inhibiting the growth and reproduction of microorganisms, and finally inactivating them. The high-energy particles and active substances produced by it can not only kill microorganisms in food and be used for food preservation, but also reduce pesticide residues, improve food processing characteristics and remove the odor in food.

Effectively extend the shelf life of fruits and vegetables

In order to effectively improve the level of industrial application of plasma technology and solve the problems of preservative preservation and quality safety of agricultural products and food, in October 2020, the Capital Agricultural Products Safety Industrial Technology Research Institute of Beijing University of Agriculture was established “ Plasma Engineering Center (Passman · Laboratory), and invested special incubation funds to establish a research and development team with Sun Yunjin as the core, responsible for the full industry chain application research and development of low temperature plasma technology in agricultural production and food processing. Based on low temperature plasma, the R&D team adopts the original air isolation and penetration elimination technology, and then constructs the digital open and accurate management and control system through the intelligent cloud service, realizing the rapid integration of various application scenarios.

The Chinese toon is a favorite vegetable, known as Toon. Tree vegetables. However, it is difficult to store and tastes different when frozen. In order to break the bottleneck restricting the development of the Chinese toon industry, Sun Yunjin team developed plasma gas preservation technology that can improve the shelf life of Chinese toon, broke the technical barrier of fresh Chinese toon preservation, extended the shelf life of Chinese toon and helped to extend the industrial chain.

The research team took the fresh Chinese toon as the research object, according to the size of the toon was divided into two groups, respectively 0 and 10 minutes after electricity treatment in 4℃ storage, every 2— The observation was recorded for 3 days. The control group was slightly wilting and smelled stronger from day five, the researchers said. From the 7th, 9th day began to smell weak, wilting degree is too large; Hair begins to grow at 19 days and smells rotten. The plasma treatment group showed no obvious change at the beginning stage, and slightly wilted at day 19. On the 31st day, the smell is light and there is no rotten taste. After day 40, the sample was slightly hairy and wilted. In terms of appearance, both the control group and the treatment group showed color changes, that is, the beginning purplish red gradually faded to green, and the color changes in the control group were more obvious. The results show that plasma gas preservation technology can prolong the shelf life of Toona sinensis. More than 5 times, the preservation effect is outstanding.

Improve logistics elimination efficiency

As epidemic prevention and control has become routine, how to kill express packages and whether they are safe and reliable have become a topic of concern. It is a difficult problem for logistics companies to ensure the safety of express packages and realize all-round cancellation. A few days ago, Sun Yunjin team research and development of super ion elimination technology delivery package surface virus and bacteria elimination conveyor, put into trial operation in Beijing University of Agriculture Cainiao post station. The device is easy to operate and supports field operation, from sample processing to sterilization in 30 seconds. Using air plasma cold sterilization technology, the device can be used to disinfect objects such as express packages, personal belongings and food, and effectively eliminate more than 20 viruses and bacteria, including the novel coronavirus, E. coli, bird flu and norovirus.

The successful operation of the super-ion sterilization conveyor not only provides a further guarantee for the prevention and control of the epidemic on campus, but also means that the air plasma cold sterilization technology solution has been successfully transformed into a product solution, which has the basis of providing sterilization services for the logistics industry. A person in charge of an express delivery company said that compared with traditional disinfectant spraying disinfection, disinfection with this device will not cause irritation to the skin, so it is invisible to the delivery. Safety lock .

Sun Yunjin said that from the current point of view, the products developed by this technology can provide whole-process integrated elimination solutions for logistics. It is believed that in the future, plasma technology can provide one-stop solutions for epidemic prevention and safe production of livestock and poultry around the whole industry chain.