Moisture is one of the food packaging sector’s darkest adversaries. Not only does it have an detrimental effect on the shelf life of convenience foods, but such products often contain hygroscopic ingredients which actively attract water particles. Minimising moisture ingress to the required extent is therefore a constant challenge for the packaging and food sectors.

Three key weapons have emerged in the battle against moisture: combining materials with greater barrier qualities, applying the latest sealing technologies and implementing moisture regulation systems.

Regulating moisture

Moisture regulation is particularly important in convenience foods. By regulating moisture levels within a food package environment, a company can limit moisture-mediated degradation, such as microbial spoilage. Furthermore, regulation can help preserve the appearance and flavour characteristics of the product, therefore extending shelf life and protecting brand integrity.

“Moisture regulation technology is particularly essential for those food products that require a certain moisture level to maintain texture, such as cookies or cakes.”

The technology required to do this revolves around the concept of equilibrium relative humidity (ERH). ERH is achieved by maintaining the desired level of humidity by releasing or absorbing moisture. If implemented successfully, it can prevent moisture transference between the product and packaged environment as well as prevent moisture levels from becoming too high or low.

Moisture regulation technology is particularly essential for those food products that require a certain moisture level to maintain texture, such as cookies or cakes. Here, ERH must be maintained at an intermediate level by providing a package that comes with a pre-determined amount of moisture. These levels can be customised to suit the specific requirements of the packaged food products. The moisture is then released and reabsorbed over time according to the conditions surrounding the
packaged environment.

The technology can be delivered in packaging applications through a range of customised product formats.

Depending on the food product and package design type, the following formats can be used: a sachet, canister, compressed tablet, large format bag or self-adhesive label. They all are dry to touch and therefore maintain their structure regardless of the moisture they hold. It is also possible to integrate insertion into packaging lines.

The problem with moisture

Throughout the supply chain products are transported or stored in a variety of challenging environmental conditions. With temperatures and humidity levels increasing and decreasing, the capacity and propensity of air within a successfully packaged product to store moisture will likewise increase and decrease accordingly. A packaged environment that is too moist or dry, however, can damage product integrity causing the food product to become stale or soggy.

The range of food product types that require moisture regulation technology is vast. As well as baked goods, products such as dried meats and fruits, and certain confectionary such as nougats and caramel, need careful moisture regulation. An appropriate moisture regulation solution must be established for each food product, which is measured according to optimal relative humidity (RH) levels. Dried products such as beef jerky, for example, have an optimal RH of 65-75%, while moist products
such as baked goods have a higher optimal RH of 80-90%.

Finding the perfect packaging

As well as establishing the optimal RH level for a food product, the packaging material and format must also be taken into account if an appropriate moisture regulation solution is to be developed. Finding a material that has the protective qualities to maintain the unique set of characteristics for each food product is a stark challenge for the packaging industry.

This challenge is extended further by today’s market, which requires moisture regulation technology to address environmental concerns. The industry has made great strides in this field in recent years with oxygen-mediated degradation being a shining example of just how much progress has been made. Meals Ready to Eat used by the US Army, for example, degrade simply by being exposed to moisture and oxygen. In certain applications, moisture regulation technology can even be used
in conjunction with activated carbon to manage volatiles, which can cause odours.

Parts of this article originally appeared on our sister website Packaging Today: