Are you producing high-quality mushrooms? If yes, then how do you make sure that your customers are getting this high quality?
In today’s video, I want to talk about a research paper that analyzed different packaging materials to extend the shelf-life of Flammulina velutipes, known as the golden needle mushroom or enoki mushroom.
The quality of your mushrooms is determined by their color, texture, odor, and appearance. These factors will change after the harvest over time as the mushrooms are still metabolic active. How fast these changes occur depends on, for example, the strain, the storage temperature, and humidity.
In the case of the enoki mushroom, the shelf-life ranges at room temperature between 1 to 3 days. If the mushroom is kept at 4°C/39°F, the shelf-life can be increased to 4 to 7 days. This is increased shelf-life comes to no surprise as the metabolic activities are slowed down at lower temperatures.
It is, therefore, a good practice to immediately cool down the fresh harvest mushrooms to about 1 to 2°C (34 to 36°F). It is important to maintain this temperature along the cold chain.
Besides the temperature, the respiration rate of the mushroom, which is influenced by carbon dioxide and oxygen concentration has an impact on the shelf-life. Mushrooms should be therefore stored in packages containing a modified atmosphere or a controlled atmosphere.
Until now, enoki mushrooms are packaged in a tray and a wrap and stored at 1°C ( 34°F). In doing so, they maintain their freshness for up to 15 days. If they were instead packaged with anti-fogging film and stored at 0°C (32°F), it is said that they can preserve their freshness for up to 28 days.
As the storage temperature at the market is known to be around 10°C, it is difficult to judge if the shelf-life can be maintained.
To figure out the best packaging material, today’s research paper compared low-density polyethylene (LDPE), oriented polypropylene (OPP), and a mixture of polyethylene (PE) with polypropylene (PP) films with each other.
The goal: To extend reliable shelf-life for 2 weeks at 10°C (50°F).
Here are the results:
RQ is the ratio of carbon dioxide produced and oxygen consumed. A value greater than 1 indicates that an anaerobic respiration is happening, which is the case for low-density polyethylene. Using oriented polypropylene and the combination of polyethylene and polypropylene protects the mushroom.
The color of a mushroom is an important factor in consumer acceptance and marketability of the mushroom. The color is expressed as the L-value, which represents the brightness of the sample. The test showed that browning or receding occurred already after 3 to 4 days from the date of formation, which is indicated by a decreasing L-value. The L-value of the golden needle mushroom immediately after the packaging was 85. After one week, the value for LPDE was 70, for the combination of PE+PP it was 79, and for OPP the value was 83. After the second week, the values were 75 for LPDE, 75 for PE+PP, and 79 for OPP.
One of the main characteristics associated with mushroom deterioration is the changes in texture during storage. The texture immediately measured after the packaging was 3.1 N/mm². After the first week, the values were for LDPE 2.2 N/mm². Meaning a softer tissue.
For the combination of PE+PP the value was 2.7 N/mm² and for OPP the value was 2.8 after 1 week. After the second weeks, the values changed to 2.2 for LPDE, 1.8 for the combination of PE+PP, and 2.4 for OPP.
Spoilage is the time when the browning of the stem and the deterioration due to the decay occurred. Therefore, the higher the spoilage the higher the scores were assigned. The spoilage for LPDE was after the 1st week 30%, and 65% after the 2nd week. For the combination of PE+PP the spoilage was 5% after the 1st week, and 30% after the 2nd week. For OPP the values were 5% after 1st week, and 25% after the 2nd week.
To test the sensory values 10 people rated on a scale from 1 to 5, with 5 the highest value. The following parameters. Fresh opening degree Stem height (not shown), Stem browning, off-flavor, and purchase intention (not shown).
To summarize, the packaging with OPP oriented polypropylene maintained the overall mushroom quality over 14 days at 10°C (50°F).
If you are interested in increasing the biological efficiency of the enoki mushroom, then the video on the right is for you.
If you instead want to increase the shelf-life of oyster mushrooms, then the video on the left is for you.
Talk to you there.
📝 Sooyeon Lim, Yoon Pyo Hong, Eun Jin Lee, Jongkee Kim, Ji Hyun Lee, Ji Weon Choi. Extension of shelf-life in golden needle mushroom (Flammulina velutipes) according to pressure composition packaging using oriented polypropylene film. 2014; 21(6):767-775 pISSN: 1738-7248, eISSN: 2287-7428 DOI: https://doi.org/10.11002/kjfp.2014.21.6.767