Are you looking for an effective way of storing mushrooms and extend their shelf life? Mushrooms are just one of the many food items that are better in the refrigerator. A chiller temperature between 34 °F (1 °C) to 45 °F (7°C) ensures that what inside stays fresh. However, unlike most refrigerated food items, mushrooms are very different. While others do fine inside an airtight container, mushrooms need a very different approach.
But sadly, some people treat mushrooms the same way as those other refrigerated foods. Some would wrap mushrooms in plastic before storing them the refrigerator. This is definitely a bad way of storing them. Instead of prolonging the shelf life of the mushrooms, it just speeds up the deterioration process. What’s wrong here?
What’s worst with mushrooms is that even if extra care is given during storage, they still have a relatively short shelf life. Mushrooms last 7 days to 2 weeks, depending on the kind. Nonetheless, storing mushrooms properly will ensure a prolonged shelf life. So what’s the best way of storing mushrooms?
You might also like: Shelf Life Of Common Refrigerated Foods
MUSHROOMS AND RELATIVE HUMIDITY
There are actually many kinds of mushrooms. Each of these kind has a varying composition, as well as the amount of nutrients. But generally, mushrooms contain around 85–95% moisture content, 3% protein, 4% carbohydrate, 1% minerals and vitamins, and 0.3–0.4% fat. What would make a difference here is the very high moisture content. Because of this, mushrooms require an environment that has a high relative humidity.
What is relative humidity?
Relative humidity refers to the amount of moisture content present in the atmosphere. This is expressed as a percentage, which indicates the amount of moisture that can be retained by the atmosphere given the same temperature.
The recommended relative humidity for storing mushrooms is between 80-90%. If it is lower than 80%, and the mushrooms are exposed to a constant low humidity, they will eventually lose moisture. This usually results in undesirable changes in the physical and chemical properties. These changes include brown spot formation, slimy, and sometimes pitted—common indication that it is time to discard them.
This is why air tight or enclosed containers are not ideal for mushrooms. They not only provide low moisture, but they also prevent proper air flow. But do not provide excessive air flow either or the mushrooms will quickly dry out.
Here is how to properly store mushrooms.
STORING MUSHROOMS
When you source mushrooms from a store, ensure you are purchasing them fresh. Once home, you want to bring the temperature of the mushrooms down immediately. Mushrooms continue to produce and release heat even after picking. This, too, hastens spoilage. To store them in the refrigerator, place them in a paper bag unwashed, and then fold the top, and place the bag on a shelf, ideally, in the main compartment.
Question— why not in an enclosed or airtight container?
Simple. A paper bag is a porous material— it contains minute holes. These holes allow the paper bag to absorb the excess moisture from the mushrooms to prevent them from going soggy, moldy, and slimy. Or simply, they keep the mushrooms safe and fresh.
Commercially, the humidity of the environment and the respiration rate of mushrooms are what the growers control to prevent spoilage and losses.
You might also like: Are There Fruits That Continue To Ripen After Harvest?
MUSHROOMS AND MODIFIED ATMOSPHERE PACKAGING
The variables that define the shelf life of mushrooms are carefully controlled to prevent losses. These variables are the CO2, oxygen, and humidity. One way to do this is by employing modified atmosphere packaging (MAP). MAP is just one of the many techniques employed in the food industry to extend the shelf life of various food products. This technique is ideal for storing mushrooms as it provides a cheap yet effective way of minimizing or inhibiting biochemical processes.
The level of oxygen is one factor that dictates the rate of respiration of mushrooms, specifically. The higher the concentration of oxygen that there is, the higher the respiration rate of the mushrooms. And therefore the faster they spoil. By altering the gas composition that surrounds the mushrooms inside the package, the processes that contribute to deterioration are delayed. Using MAP, the oxygen levels can be decreased while increasing the levels of carbon dioxide in the pack. Doing so prevents spoilage and results in prolonged shelf life of mushrooms. MAP is usually combined with low temperature storage (both lower rates of processes in food).
When selecting packaging film for mushrooms, the film’s characteristics are carefully assessed if applicable. Mushrooms are one of the few high-respiring produce. For this reason, typically films such as OPP (oriented polypropylene) and LDPE (low-density polyethylene) do not work well since they are not gas-permeable enough.
Certain packaging films ideal for produce like mushrooms are modified atmosphere/modified humidity packaging (MA/MH) films. These films not only control the gas composition, but as well as the humidity. Films with modified humidity favorable to mushrooms avoid moisture loss, wilting, and other undesirable changes. This allows mushroom growers to transport their product to distant areas.
