Fortunately, Versaperm has developed a way that to measure the critical property reliably and accurately, using its latest range of permeability measurement equipment. Additionally, as permeability varies with the absorption and temperature of both the food and the coating, the equipment has an in-built oven which can mirror the cooking process.
The Versaperm meter has a highly automated computerised control and can cope with several products at the same time - giving results that are typically accurate in the parts per million range. It can be configured to measure the diffusion rates of most gaseous elements including water vapour, oxygen and nitrogen.
The same instrument can be used to measure the permeability of the edible films products and the packaging used for the finished product.
As an added advantage it is easy to use, requiring at most minimal training and can sometimes give results in as little as 30 minutes. Conventionally gravimetric measurements may take several days to weeks and give significantly less reliable results.
For companies who do not require their own equipment for quality control or development, Versaperm also offers a laboratory / QC testing service.
As a quick overview to edible films: Polysaccharides including cellulose, chitosan and starch and, proteins such a zein and collagen, and lipids such as triglycerides and fatty acids, can all be used as edible film-forming materials. Polysaccharide films are low cost but only provide a low moisture barrier. Protein films have good plasticity, elasticity, and good oxygen barrier properties but only offer poor water vapour resistance. Lipid films have good moisture barrier properties but poor oxygen barrier and mechanical properties.