Driving out the damp

It is undeniable that moisture has a severely detrimental effect on convenience food shelf-life. Many convenience foods contain hygroscopic ingredients, and it is difficult to minimise moisture ingress to the required extent. This is achieved by combining materials with good barrier qualities, applying the latest technologies (such as those for sealing) and moisture regulation systems.

Packaging Today caught up with Robert Sabdo, Multisorb Technologies, to discuss how moisture regulation can help maintain the shelf stability and product quality of convenience food products.

Packaging Today: Why is moisture regulation important in convenience foods?

Robert Sabdo: Regulating moisture levels within the food package environment limits moisture-mediated degradation, such as microbial spoilage, and preserves the appearance and flavour characteristics, thereby extending shelf-life and protecting brand integrity.

Packaging Today: How does moisture regulation technology work?

Robert Sabdo: Moisture regulation technology maintains the desired level of humidity by releasing or absorbing moisture to establish equilibrium relative humidity (ERH). This prevents moisture transference between the product and packaged environment, stopping moisture levels from becoming too high or low, which can adversely affect product quality.

For some food products, it is preferable to maintain ERH at some intermediate level, allowing the product to absorb limited amounts of moisture. With such baked goods as cakes or cookies, a certain moisture level is desirable to maintain texture and ‘mouthfeel’. In this case, moisture regulation technology provides a package with a pre-determined amount of moisture, which is customised to suit the specific needs of the packaged food product. The moisture is released and reabsorbed over time, responding to conditions affecting the packaged environment.

Packaging Today: How does moisture regulation technology help food manufacturers transport or store their products in challenging environmental conditions?

Robert Sabdo: Throughout long distribution chains, packages may be stored and shipped in climates with varying temperatures and humidity levels. As the temperature increases or decreases, likewise does the capacity – and propensity – of the air within the package to store moisture. A packaged environment that is too moist or too dry can damage product integrity, causing it to become stale or soggy.

Packaging Today: In which food product types is moisture regulation technology commonly used?

Robert Sabdo: It is commonly used in a wide range of food products, including baked goods, dried meats and fruits, and certain confectionery types, such as nougats and caramels. This technology regulates moisture to an optimal relative humidity (RH) level as required by different food products. For example, baked goods generally require an optimal RH of 80–90 per cent as they are fairly moist. On the other hand, such dried products as beef jerky have an optimal RH of 65–75 per cent. In addition to optimal RH levels, the packaging material and format must be taken into account when developing an appropriate moisture regulation solution. This can vary significantly between products as each food has a unique set of characteristics that must be maintained whilst considering the protective qualities of each packaging format.

Another important factor to note is that, depending on the application, moisture regulation technology can be configured to address other environmental concerns. For example, when combined with oxygen scavengers, protection against both moisture- and oxygen-mediated degradation is achieved. This is the case for Meals Ready to Eat (MREs), as used by the American military, which degrade by exposure to moisture and oxygen. In certain applications, moisture regulation technology may be used in conjunction with activated carbon to manage volatiles, which can cause odours.

Packaging Today: How is moisture regulation technology delivered in packaging applications?

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