What is the progress of nano-food application research?

When Pasteur invented the process of pasteurization, he brought the precision of food production down to the micron level and completed the first revolution in the food industry.
When Watson and Crick discovered deoxyribonucleicacid (DNA) and conceived a DNA structure model at the 2.5nm level, they reduced the human perspective to the nanometer level, opening the door to the nanoworld of biotechnology, agriculture and food production. The food industry then completed the second revolution, and the real mark of the arrival of the nano age of the food industry was the discovery of carbon nanotube-buckyball fullerene (C60), which extended the level of food production to the level of 1 nanometer.
Nanocorrelation concept
Natural existence, engineering synthesis or accidental generation, in the form of binding state, aggregation state or agglomerate, and the form of one-dimensional or multidimensional size within 1nm~100nm of the substance is called nanoparticles, as long as the internal composition or the surface of the material containing nanoparticles is nanomaterials; At the same time, fullerenes (C60), nanofibers, single-walled carbon nanotubes and graphene sheets with one-dimensional or multidimensional dimensions of less than 1nm are also special nanomaterials.
Based on the study of the special physical and chemical and biological properties and phenomena of nanomaterials, and using the special properties of nanoparticles, the science and technology of redesigning, transforming or assembling nanoparticles into new materials, devices or systems is nanotechnology.
In short, “nano” is not only limited to the measurement of spatial scale, it provides a new way of thinking for human to explore the scientific unknown, which can enable human beings to meet the needs of higher levels from the more micro level of the objective world according to their own will, so as to enhance the welfare surplus of human society.
As for nano food, the current international has not yet formed an exact definition. According to the concept of nanomaterials and nanotechnology, it can be seen that natural, synthetic or biological products that can be eaten by humans are used as raw materials, and foods prepared by using nanotechnology are nano-foods according to human health and nutritional dietary needs. From a broad perspective, as long as nanomaterials or nanotechnology are involved in the entire process of the pre-production link (agricultural production link), production and processing link, packaging, storage and transportation link, etc., the food produced can be called nano food.
Because the existing scientific knowledge is not yet able to fully evaluate the application of nanotechnology in the field of food, while contributing to social development, nano-food has certain risks and hidden dangers to human health, biological environment, social ethical order, etc., which has increased the heat of research on nano-food to a certain extent.
Food applications – international scope
With the development of nanotechnology, its application scope involves 1805 kinds of products in 37 fields in 8 major industries such as home appliances, automobiles, electronics, food (beverage) products, and home gardening. Its application in the field of food is also more extensive, in the period from 2009 to 2012, the number of patents on nano food as many as 186, 10% of the patents are related to food safety testing, 19% are related to nano food additives, 47% are related to food nano packaging materials.
It can be seen that the application of nanotechnology in the field of food is mainly concentrated in three aspects: food additives, food packaging materials and food safety testing.
From the perspective of the food production chain, there are four links involved in the production of nano-food:
First, the pre-process of food production, mainly refers to the agricultural production process, which will use pesticides, fertilizers and other agricultural inputs containing nanomaterials, agricultural inputs will have residues in agricultural products, and edible agricultural products are raw materials for food production, therefore, the process is the source of nanomaterials;
The second is food processing, which involves nano-food additives, nano-production equipment and technology;
Third, nano-food, that is, food containing nanoparticle components or packaging materials containing nanoparticle components;
The fourth is the food safety and testing process, using nanotechnology to synthesize specialized sensors to detect nano components and safety in food.
From the specific type point of view, at present, in the food market, from livestock to aquatic products, from eggs and milk to vegetables, from fresh products to manufactured products, the corresponding nano-food can be seen.
For example, milk containing nano-casein, nano-cellulose meat, nano-silver cookies, nano-liposomal olive oil and other foods closely related to public life.
According to data on the website of the Project on Emerging Nanotechnology (PEN) in the United States, as of November 2014, 116 nanofoods had been developed worldwide, compared to only 6 nanofoods in 2006 and before. Nano-materials involved in nano-food are mainly nano-zinc oxide, nano-silicon dioxide, nano-silver, nano-gold, nano-copper, nano-cobalt, nano-magnesium, nano-calcium, nano-carbon materials, nano-fibers and other material materials. In addition, the origin of these nano products shown on the PEN website is mainly concentrated in the EU member states, the United States, Japan and other countries and regions.
Application – domestic scope
The application of nanotechnology in the field of food science in China is still in the exploratory stage, but China, as a country with the rapid development of nanotechnology in the world, has developed and applied the number of products related to nano-food is far more than 7, from the application development situation, the application of nano-food in China is mainly reflected in 3 aspects:
First, the development and application of nano functional food. The development of nano functional food focuses on two major areas: nanoparticle delivery system (functional food carrier system) and functional food nutrient additives. The main purpose of functional food carrier is to enhance the absorption of nutrients by the human body and prevent docosahexaenoic acid. DHA), vitamins and other nutrients oxidized and metamorphic, the specific applications are lipid nanomicrocapsules, enzyme nanomicrocapsules, bioactive substances nanomicrocapsules, such as carotenoid nanomicrocapsules, DHA nanomicrocapsules, ash-amylase nanomicrocapsules, nano emulsion embedding technology is also applied in the development of functional foods.
However, due to the potential biological toxicity of nanoemulsion, the application of this technology has some limitations. Nano-nutrition additives are a kind of nano-food that can increase the direct absorption of trace elements by the intestine and reduce the toxic side effects of the interaction of trace elements in the human body, such as nano-calcium, iron, zinc, selenium, etc., in food.
The second is the food nano packaging materials. At present, the application of domestic nano-packaging materials is mainly to reduce water absorption, antibacterial coatings, time and temperature indicators (the temperature range that can be tolerated on the basis of ensuring freshness and shelf life); Concentrate on nano preservation materials, nano antibacterial materials, nano barrier materials 3 aspects; Specifically applied to food preservation are nano Ag preservation materials, nano TiO2 preservation materials, nano SiOx preservation materials, nano molecular sieve preservation materials and other types.
For example, PE/Ag2O nano packaging bags can effectively reduce the rot rate of fruits and vegetables; Nano TiO2 chitosan composite membrane can prevent the loss of VC in young ginger. Nano SiOx fresh-keeping fruit wax can reduce the hardness of apple and reduce the weight loss of apple. After blending ZnO nanoparticles with different polymers, different types of nano-antibacterial materials are obtained. For example, ZnO/PVC film can effectively inhibit the growth of bacteria such as Escherichia coli in food and extend the shelf life of fresh food. In terms of nano barrier materials, polyester nano plastics are widely used, which can make dairy products, beer and other foods maintain fresh taste for a long time.
The third is nano food safety detection. The application of nano detection is mainly manifested in the development of biosensors based on nanomaterials and the integration of nanomaterials with traditional food safety detection technology, covering all aspects of food safety detection, such as sample pretreatment, sensor preparation, detection and analysis signal generation.
Due to the strong specificity of nanobiosensors, there are deficiencies in the quantitative detection of food safety, and the application is limited. In general, the technology of fusion of nanomaterials in traditional food safety testing is widely used, for example, carbon nanotubes, gold nanoparticles, quantum dots, magnetic nanomaterials, etc., are widely used in the detection of agricultural and veterinary drug residues, microorganisms, nitrites, phenolic compounds and heavy metals in water quality, and genetically modified foods.