New bio material options in film coatings for food packaging

Choosing the right packaging is a key issue in the food industry. Companies need to protect food products from oxygen, moisture and chemical and biological contamination while keeping them fresh for as long as possible. Transparent multilayer films, in which each layer offers specific benefits, are frequently used to protect food from contamination. To minimize the amount of oxygen that penetrates the packaging, companies typically use expensive, petrochemical-based polymers such as ethylene vinyl alcohol (EVOH) copolymers as barrier materials. Researchers working on the EU�s �Wheylayer� project have been using whey protein instead of petrochemical-based polymers. The natural ingredients in the whey extend the shelf life of food products, and the whey protein layer is biodegradable. The results of the research are promising. The team has managed to develop a whey protein formulation that can be used as the raw material for a film barrier layer, along with an economically viable process which can be used to produce the multifunctional films on an industrial scale, says Markus Schmid from the Fraunhofer Institute for Process Engineering and Packaging IVV in Freising. The researchers from the IVV began by purifying sweet whey and sour whey and producing high purity whey protein isolates. They tested a range of different modification methods to obtain suitable proteins with outstanding film-forming properties. To enable these proteins to withstand the mechanical loads involved, they were subsequently mixed with differing concentrations of various softeners and other additives, which were also biobased. The search for the perfect formula was a tricky process for the researchers- use of too many softeners leads to the barrier effect against water vapor and oxygen decreasing, which means that the food is no longer adequately protected. In the end, the researchers not only found the optimum formula, but also came up with a suitable, economically viable and industrial-scale method of applying whey protein coatings to plastic films and combining these with other films using different technologies. The overall process produces multilayer structures with barrier functions which can be used to produce flexible, transparent food packaging materials. IVV's work to manufacture a multilayer film of this kind using a roll-to-roll method is a world�s first. Companies that choose to make the switch to whey proteins in the future will only need to make minor modifications to their plants. The researchers have already applied for a patent on their new technology.

An edible film that can be used for wrapping ready-to-eat meat products and can kill a food-borne pathogen has been discovered by food scientists in Penn State's College of Agricultural Sciences. This is an edible film can be used for wrapping ready-to-eat meat products. It will also emit a slow release of a naturally occurring antimicrobial agent capable of killing a foodborne pathogen. The study was published in Journal of Food Safety, The researchers showed the effectiveness of pullulan films containing antimicrobial sakacin A to control Listeria monocytogenes growth. The study confirmed the feasibility of using active pullulan films to deliver a bacteriocin directly to a food surface. Pullulan film is a biopolymer, polysaccharide film. It is produced by the fungal organism Aureobasidium pullulans. Pullulan is a colorless, tasteless film that is resistant to oil and is largely impermeable to oxygen. Sakacin A is a bacteriocin produced by a strain of Lactobacillus. As soon as the pullulan film contacts a moist surface such as meat, it meshes right into the surface, and as it dissolves, it releases the antimicrobial.

An edible film based on simple tomato puree might be able to protect foods from contamination by E. coli and other bacteria, according to a study conducted by researchers from the U.S. Department of Agriculture's Agriculture Research Service and the Western Regional Research Centre, Processed Foods, and published in the Journal of Food Science. The researchers made an edible, food-coating, tomato-based film and added the chemical carvacrol in concentrations of 0, 0.5, 0.75, 1.0 and 1.5 percent. They then inoculated these films with the O157:H7 strain of E. coli. Carvacrol is the primary ingredient in oregano oil. The researchers found that the carvacrol films successfully inhibited bacterial growth and were most effective at a concentration of 0.75%. Demand for natural antimicrobial produces is growing as consumers become increasingly wary of synthetic preservatives. The researchers noted that since the antimicrobial film tested in their study is tomato-based, it might actually provide some of the same health benefits as eating the fruit.