Application research status of nano cellulose in food industry

Nanocellulose is the general term for natural cellulose with a nanometer scale. Nanocellulose has both the physiological properties of cellulose and the physical and chemical properties of nanoparticles, which makes it suitable for high-end composite materials, biomedicine, food industries and other fields. Very high application value. In the food industry, the application of nano-cellulose is becoming mature. Nano-cellulose is not digested and absorbed by the human body. It has the effects of promoting intestinal peristalsis and improving the ecological balance of intestinal flora, as well as good rheology and hydrophilicity. It can form a stable colloidal solution, so that nano cellulose can be used as a non-nutritive ingredient, thickener, stabilizer, etc. in the field of food additives. Nano cellulose has the characteristics of non-toxic, harmless, biodegradable, high crystallinity, etc., and can be given unique properties and capabilities through surface modification, making it suitable for food packaging.



According to the preparation method and size of nanocellulose, nanocellulose is mainly divided into three categories: microfibrillated cellulose (MFC), nano cellulose crystals (NCC) and bacterial nano cellulose (BNC).



Microfibrillated cellulose (MFC), also known as cellulose microfiber, microfiber cellulose or nanofibrillated cellulose. MFC is a one-dimensional nano-level new polymer material obtained by mechanical treatment of natural cellulose. Due to its large aspect ratio and network structure, high mechanical properties, high expansion surface area, high aspect ratio, light weight and other characteristics, more and more attention has been paid.



NCC has significant characteristics such as rigidity and high stability, and is reproducible and economical. Its nanostructure is suitable for cosmeceutical products, nanocarriers and drug delivery systems, packaging materials and food additives.



Bacterial cellulose is a three-dimensional network structure with high crystallinity that is formed by the metabolism of various bacteria and does not contain lignin, hemicellulose and other extracts. This structure makes BNC have some unique characteristics, such as high purity, high crystallinity, greater mechanical strength, high water retention value, antibacterial properties, non-toxicity, biocompatibility, and biodegradability, etc., which are used in many fields. It has a wide range of applications, such as biomedicine and tissue engineering, food, electricity, papermaking, functional materials, etc.
Application of nano cellulose in food industry



As a hydrolysate of natural cellulose, nano cellulose has dual physical and chemical properties of cellulose and nanoparticles, such as pure natural, no odor, safety, non-toxic, good rheology, and high water holding capacity, and is widely used in all aspects of the food industry. .



1. Baked food



Nano cellulose has the effects of dietary fiber that is not digested and absorbed by the human body, but can promote intestinal peristalsis and improve the ecological balance of intestinal flora. It can be added to baked foods to make diet foods or functional foods. For example, using bagasse as the raw material to prepare microcrystalline cellulose and nanocellulose, and to make dietary fiber bread respectively, through the analysis of the quality, sensory score and texture of the two dietary fiber bread and the blank control bread By comparison, it is determined that the optimal cellulose addition is 8%, and the quality of nanocellulose bread is better than microcrystalline cellulose bread, and microcrystalline cellulose bread is better than the blank control group.



As a dietary fiber, nanocellulose has better hygroscopicity and rheology than microcrystalline cellulose. The application of nanocellulose in food can not only utilize the scale effect of its nanomaterials, but also exert its physiological characteristics, making nanocellulose Dietary fiber has attracted attention in food research and development. Select Gluconoacetobacter to ferment to prepare bacterial nanocellulose and add it to wheat bread. By analyzing the rheological parameters of wheat bread before and after adding bacterial nanocellulose, the addition of bacterial nanocellulose can improve the quality of bread It improves the specific volume, porosity, luminosity and moisture retention, reduces the browning index, reduces the hardness of the crumbs, and makes the bread more tender.

2. Frozen food



Adding an appropriate amount of nano cellulose to frozen food can make it have better lubricity, which allows food to maintain good stability, avoiding the formation of large ice crystals during freezing or repeated freezing and thawing, so as to maintain the delicateness of frozen food Taste.



The addition of nano cellulose can improve the melting resistance and stability of ice cream, make ice cream texture more delicate and ice crystals smaller, thereby improving the quality of ice cream. The results show that adding 0.35% of nanocellulose can optimize the texture, stability and flavor of ice cream. And nanocellulose also has the physiological characteristics of dietary fiber, which is in line with the current development trend of food regimen. A composite gel (nano-BC/SPI) made of nano bacterial cellulose (NBC) and soybean protein isolate (SPI) as raw materials and added to ice cream. The addition of NBC can improve the TPA distribution, suspension stability, emulsification and rheological properties of the composite gel. Among them, the mixture of NBC/SPI of 1:20 has the highest overall similarity with cream and can be used as a fat substitute.



3. Food packaging



Food packaging is an important part of the food industry. It is necessary to avoid external pollution and keep freshness of the packaged food, but also consider the degradability, non-toxicity and non-pollution of the food packaging materials. As a renewable and biodegradable natural polymer, nanocellulose is favored by researchers because of its antibacterial properties and good mechanical properties.



Using wheat gluten (WG), cellulose nanocrystals (CNC) and TiO2 nanoparticles as raw materials, bio-nanocomposites have been developed. Studies have shown that adding 7.5% CNC and 0.6% TiO2 to the WG can significantly improve the properties of the studied composite material, such as morphology, tensile strength, water vapor absorption, water vapor permeability, and contact angle. Coating commercial packaging primary color kraft paper with nanocomposite materials can significantly increase the breaking length, burst index and antibacterial activity of the coated paper, which makes the coated paper have great potential in packaging applications.



The green method of using coupling agent to immobilize nisin on bio-based carboxylated cellulose nanofibers (CNF) is a green method for making food packaging, which has good antibacterial activity and ensures long-term storage of food. Nano cellulose coating is coated on the inner surface of food packaging or directly on the surface of food materials that need to be preserved. Compared with ordinary coating materials, nano cellulose has a special gas barrier function, which can improve mechanical properties and make It has great potential for development in the field of flexible biological packaging; both microfibrillated cellulose and nano-cellulose crystals are high polymers, with high bonding energy and strong inter-chain attraction. Under low humidity conditions, their voids It is small in size and limited in diffusion, so it has low air permeability, which can further improve food quality and safety, with high efficiency and low cost.

In addition, nanocellulose can also be used in milk preparation, meat products, beverages, etc., and because of its good biocompatibility, it can also be used as a carrier for immobilized enzymes, used in biosensors through surface modification, and for making Food grade materials and many other fields.



Nano cellulose has physical and chemical properties such as pure naturalness, no peculiar smell, safety and non-toxicity, high crystallinity and high water holding capacity. It is also a non-digestible polysaccharide necessary for the bodys balanced diet. It has beneficial physiological functions such as lowering cholesterol, regulating blood sugar, preventing colorectal cancer and cardiovascular disease. It not only conforms to the health, nutrition and low sugar of modern diet, but also conforms to the purpose of green sustainable development. It is a natural, renewable, and naturally degradable material, and it is a natural nanomaterial with a wide range of applications.



references:



[1] Tian Yinghua, Zhang Yufei, Jin Haiyan, Liu Xiaolan, Wang Zhe. Nanocellulose and its application in the food industry[J/OL]. Cellulose Science and Technology: 1-7[2020-12-12].https ://doi.org/10.16561/j.cnki.xws.2020.04.06.



[2]Cai Chenchen, Lu Dengjun, Ma Ruijia, Liu Tao, Fan Biaoxi, Lu Mingda. Research progress in the application of nanocellulose in the food industry[J]. Food and Machinery, 2019, 35(07): 231-236.



Keywords: Nano cellulose, food additives, functional food, food packaging



Text/Small Silt



About the author: Xiao Yisha, a food science and technology worker, graduated from the School of Food Science and Engineering, South China University of Technology, with a masters degree in food science. Now he works for a large domestic drug research and development company and is engaged in the development and research of nutritious food.