Edible packaging film using casein

Edible packaging film is a research hotspot of packaging materials in recent years. General edible packaging film is based on polysaccharides, cellulose and protein as the main basic materials, compounded with esters and other organic materials, forming an edible packaging film with good mechanical processing properties. Protein as a basic material for edible packaging films has many advantages. However, the previous protein extraction is generally limited to plant materials. Most of these packaging films made of plant materials do not have water resistance and moisture resistance, and their mechanical properties are greatly reduced after water contact. Recently, U.S. researchers have experimented with a new method for the continuous production of thin films from milk proteins. With this method, edible and waterproof packaging films can be produced. Such packaging films are already available in some US dairy products. Seen in the package.

This edible packaging film is based on casein in milk and uses the unique characteristics of casein, which is the main nutrient component of cheese. It can not only be used as a food packaging film but also as a food supplement. It can also be used as a binder for food packaging, finished materials for paper and textiles, and even paints.

Casein has very good advantages as a packaging film, its natural structure making it capable of forming a water-repellent, biodegradable film or coating. Casein films can be produced as high-quality thin-coated sheets that not only adhere directly to the product as an inner laminate but can also be applied to some middle-layer packaging films. The casein wrap can protect the product from damage and contamination, forming a barrier that prevents the product from coming into contact with foreign substances. The edible film can also lock in moisture due to the water-repellent properties of casein and can therefore be used to package dairy products. For example, cheese, or a component of a laminated product used in the packaging of cottage cheese or yoghurt; some food materials such as seasonings, vitamins, or minerals may also be added to the casein wrapping film, which also improves the packaging film itself. feeding habits.

This process uses an ARS patented approach developed by Peggy Tomasula of the ERRC Dairy Processing and Product Research Unit in Wyndmoo, Pennsylvania. Her extraction method uses high-pressure carbon dioxide to separate casein from milk. The Toma-sula experiment found that if this casein was mixed with water and glycerin and was naturally dry without interference, it formed a water-resistant, soft, film-like material. The film produced from casein in the past cannot meet the needs of packaging materials. The biggest problem is that it does not have water resistance, and moisture can quickly dissolve it. The new material remains intact when immersed in water and has excellent water and moisture resistance, which is far superior to other base protein films in the past.

Previously, due to technical limitations, this type of film has not been continuously manufactured on a large scale. Recently, chemical engineers Michael Kozempel and Tomasu-la, who are retired from ERRC, have developed an incubation process for the continuous production of bovine milk protein films. The Kozempe experiment determined which type of delivery device was used to uniformly spread the casein solution, which is the easiest to move the dry film. Moreover, in order to make the film within 3 hours, he specified the drying conditions and temperature. These conditions achieve the feasibility of large-scale production of bovine casein films. This process allows the continuous production of casein packaging films and can be used to improve other proteins. This process establishes the feasibility of commercial production of biodegradable polymer packaging films from dairy products. Kozempel also confirmed that up to 20% of casein can be replaced by skimmed milk powder, which can reduce the cost of the film with little loss of physical properties. And ARS has filed patented production of continuous production processes and is looking for business partners to bring it to market. It is believed that in the near future, it can be seen that the packaging film of casein is used in food packaging and becomes a green alternative to traditional plastic packaging films.

Source: China Food News