Photo courtesy of vision china
The project team carried out comprehensive and systematic research and development, and the new technical achievements developed effectively extended the shelf life of fruits and vegetables by reducing the original pollution of spoilage bacteria in vegetables, preventing the rapid propagation of spoilage bacteria, and dynamically adjusting the gas atmosphere in the packaging microenvironment.
With the increasing variety of food ingredients and the changes of climate and environment, traditional preservation methods can no longer meet the deeper preservation needs.
On May 8th, the reporter of Science and Technology Daily learned from Jiangnan University that the research team of Yao Weirong, a professor at the School of Food Science, tackled the problem of perishable storage of fresh fruits and vegetables, and successively developed cleaning and disinfection technologies (ultrasonic technology, natural plant-derived cleaning disinfectant), new cold sterilization technologies (low-temperature plasma technology, irradiation technology), as well as preservative and active packaging film, which have been fully applied in domestic fruit and vegetable bases and storage and transportation industries.
According to Chen Wei, academician of China Academy of Engineering and president of Jiangnan University, people’s food needs are increasingly diversified. Applying modern technology to solve the storage problem of fresh fruits and vegetables will play an important role in ensuring market supply and promoting rural revitalization.
Yao Weirong introduced that leafy vegetables are easy to rot, mainly due to high water content, vigorous physiological activities after picking, high pollution of original microorganisms and high requirements for storage conditions. Therefore, relevant preservation measures must be taken in order to adjust the storage conditions such as temperature, air humidity and gas atmosphere.
In order to prevent fresh vegetables from rotting, most of them are stored in cold storage. In recent years, although there are more and more quick-frozen vegetables, this method usually requires blanching pretreatment first, which is easy to cause the loss of minerals and vitamins.
Chen Wei introduced that the food consumption structure of urban and rural residents in China was dominated by coarse grain consumption at first, and now it is rapidly transforming into a diet structure in which vegetables, fruits, meat, milk, eggs and other livestock products, aquatic products and processed foods coexist. This change makes people eat more safely, healthily and with balanced nutrition.
At present, the most effective ways to store vegetables in the world are mainly modified atmosphere preservation and irradiation preservation, which can inhibit the growth of microorganisms or vegetable tissues by improving the composition of environmental gases and using irradiation respectively, and have the effect of killing insects and sterilizing.
"Our team has carried out comprehensive and systematic research and development, and the new technological achievements have effectively extended the shelf life of fruits and vegetables by reducing the original pollution of spoilage bacteria in vegetables, preventing the rapid propagation of spoilage bacteria, and dynamically adjusting the gas atmosphere in the packaging microenvironment." Yao Weirong said.
The reporter learned that in January this year, the "magnetic field preservation technology" jointly developed by Jiangnan University and TCL passed the project technical appraisal meeting organized and hosted by China National Light Industry Federation. This indicates that China has broken the foreign monopoly of molecular preservation technology, and has stepped into technology leadership from technology catch-up.
According to relevant experts, the molecular preservation technology is to use magnetic field induction to realize unlimited micro-vector preservation, so that the ingredients can achieve the 6-day preservation effect of moistening, nourishing, beautifying, cleaning, living and fresh. This is because water molecules, organic compounds and biological macromolecules all belong to diamagnetic materials, so they will induce external magnetic fields.
At present, this latest technological achievement of integration of production and education, which has multiple functions of water locking, antioxidation and bacteriostasis, has been applied in China.
In Yao Weirong’s view, these technologies can basically solve the problem of fresh fruit storage. However, technology alone can’t do without paying attention to application and storage methods.
At present, it is still difficult for some agricultural production bases and storage and transportation enterprises to package and store all kinds of vegetables in a targeted way. In order to reduce costs, transportation and storage often enter the transportation and storage process by extensive and simple dressing, and there is no independent packaging at all, resulting in vegetables not being well protected.
Especially for all kinds of vegetables transported in large quantities, vegetables will squeeze each other, causing artificial mechanical damage, which accelerates the decay and deterioration of fruits and vegetables and causes serious waste.
Chen Wei believes that there are still some problems to be solved in promoting the high-quality and differentiated development of agricultural products and food industries in China. Among them, how to ensure the effective market supply of various foods such as meat, vegetables, fruits, aquatic products, etc., it is urgent to make efforts from the technical end and the supply end to open up the "last mile" from farmland to the dining table, so that the latest scientific and technological achievements can be widely used to further meet the needs of consumers for food diversification, refinement, nutrition and ecology.
