The battle to preserve food and prevent waste is as old as history.
Many different preservation methods have been discovered over time, with some delicious outcomes. Drying, curing, fermenting, pickling, and sugaring have all given rise to foods that are still enjoyed today.
Similarly, modern-day preservation methods have allowed customers to experience foods that would otherwise be denied to them based on their location, such as coffee.
Advancements in packaging technology have allowed roasters to send their coffee offerings to consumers around the globe.
These innovations include modified atmosphere packaging. Commonly referred to as MAP, this preservation method provides an added barrier against spoilage, helping improve shelf life and enhance product safety.
Modified atmosphere packaging has made it possible for consumers to enjoy “fresh” produce, including roast coffee, even if it has been shipped around the world.
Fresh produce is in demand
Sales for fresh produce rose dramatically after the onset of the Covid-19 pandemic, as customers became driven by their health goals.
Notably, sales of packaged salads increased by over 28% compared to pre-pandemic sales. Fresh fruit is experiencing similar year-on-year growth, with the demand for seasonal produce up by 12% compared to 2019.
As consumers have come to enjoy a variety of fresh, exotic produce, it seems unlikely they will be willing to go back.
The ability to preserve the quality of food has applications within the specialty coffee sector, as much hard work goes into curating the taste of the offering.
It has been well documented how age can affect coffee quality and alter flavour. Therefore, it is natural for roasters to want to ensure their customers experience the coffee as intended.
The way in which roasters choose to package their roast coffee can help preserve freshness during transit and shipping.
For instance, many roasters choose to fit degassing valves into their coffee bags to prevent the beans from oxidising.
Additionally, some may use resealable zippers or aluminium ties to make it more convenient for consumers to preserve the coffee’s flavour.
What is Modified Atmosphere Packaging (MAP)
Shipping fresh produce worldwide requires an intervention that slows the degradation of the product.
Key contributors to food spoilage are light, oxygen, humidity, and temperature – all of which can be addressed by modifying the immediate atmosphere.
This refers to changing the temperature and oxygen levels within the product’s packaging.
Oxygen-rich environments can encourage the growth of bacteria. Modifying the atmosphere to reduce oxygen and increase nitrogen or carbon dioxide (CO2) can help slow the degradation of meats and fresh produce.
Usually, this is done through controlled atmosphere rooms or containers for bulk shipping and storage.
However, for sale direct to consumers, modified atmosphere packaging (MAP) is more appropriate. MAP can be broken down into two categories: active and passive.
An example of an active MAP would be gas flashing, which is where roasters would inject gas into the coffee bag before sealing it.
The gas tends to vary depending on the product, but CO2 and nitrogen are most commonly used.
Nitrogen is traditionally used for coffee as it is an asphyxiant gas and inert. This means it is ideal to use in this context as it will slow the oxidation of the coffee.
Another example of active modified atmosphere packaging is installing a one-way degassing valve in the coffee bag. These are frequently used as they allow roasters to package their coffee soon after roasting.
During the roast, CO2 builds up in the bean and dissipates over time. Most of the gas is released within 48 hours, so roasters typically wait a few days before packing the coffee.
The problem with this is that once the residual gas has left the coffee, the beans are more prone to oxidation.
Using a degassing valve means the roaster can pack the coffee without risking oxidation, as the one-way valve will prevent oxygen from getting into the bag.
Passive MAP refers to placing oxygen scavengers and desiccants in the packaging or using a low-density polyethylene (LDPE) film.
Oxygen scavengers are small packets that usually contain clay, iron fillings, and salt. Their purpose is to displace oxygen by producing nitrogen: switching out a corrosive gas for inert gas.
The clay releases moisture into the sachet, which the iron fillings immediately begin to absorb. The presence of salt and moisture causes the iron filings to oxidise and rust, triggering the release of nitrogen. This, in turn, asphyxiates the oxygen, making it safe for food items.
Desiccants are similar to oxygen scavengers but have a different focus. The little sachets are full of Silica Gel, and their only purpose is to absorb moisture.
Barrier packaging films and low-density polyethene (LDPE), often used together, create a physical barrier between the food item and potential contaminants.
LDPE is highly gas permeable, particularly CO2. When it is used to wrap fruits and vegetables, it allows gases to escape instead of build up.
Alternatively, barrier packaging is essentially any type of packaging that creates a barrier to the product.
Can Modified Atmosphere Packaging (MAP) extend a coffee’s shelf life?
Factors such as light, heat, moisture, and oxygen are all catalysts for degradation, whether through the spread of bacteria or oxidation.
MAP tackles the problem by inhibiting contact between the product and the reactive agents.
In the case of coffee, the problem is oxygen. Degassing valves and gas flushing aim to impede contact between the two. While both will extend the shelf life of coffee, it will be to different extents.
Gas-flushing coffee can extend the shelf life of the coffee significantly, allowing roasters to ship overseas.
Consumers can then enjoy it as intended, without the shipping period affecting the quality.
With gas flushed coffee, there is more of a buffer, which can reduce the potential waste or disappointed customers. That said, set-up costs can set roasters back a few thousand dollars.
While degassing valves may not extend the shelf life of coffee to the same extent as gas flushing, they are ideal for roasters catering to the local market.
However, they are often made from different, unrecyclable materials compared to coffee bags, and many consumers are left wondering how to dispose of them.
As a result, sustainable degassing valves have become increasingly popular within the coffee industry.
Produced using injection-moulded bioplastics made from renewable resources, such as crops, recyclable degassing valves have the same properties as plastics without the environmental impact.
At MTPak Coffee, we offer fully recyclable, BPA-free degassing valves that can be recycled alongside our sustainable coffee packaging, which is made from renewable materials such as kraft paper, rice paper, or multilayer LDPE packaging with an environmentally friendly PLA lining.
Our degassing valves usually comprise five pieces: a cap, an elastic disc, a viscous layer, a polyethylene plate, and a paper filter.
Not only do they contribute to creating a user-friendly product for consumers, they also reduce the negative impact of coffee packaging on the environment.