Pleurotus ostreatus: The Ultimate Mushroom Guide

About The Pleurotus ostreatus Mushroom

The Pleurotus ostreatus mushroom is a common edible known for its oyster-shaped cap. One of the first things you should look for when trying to identify this mushroom is the presence of decurrent gills.

Pleurotus ostreatus is commonly known as Oyster Shelf, Tree Oyster, Tamogitake and Straw Mushroom.

Also, this mushroom is very similar to Pleurotus pulmonarius with some differences. The cap of Oyster mushroom is broad and fan or oyster shape. Pleurotus ostreatus prefer temperate and sub-tropical climate.

The oyster mushroom is a saprotroph, meaning it feeds on the dead and decaying matter (mainly wood).

The latin name Pleurotus ostreatus means "sideways oyster", referring to the oyster-like shape of the mushroom.

The mycelia will kill and eat nematodes (small roundworms) and bacteria, making them one of the few carnivorous mushrooms.

Pleurotus ostreatus Mushroom Look-Alikes

1. Cap

   Oyster or fan-shaped, usually 2-10 inches across (5-25 cm).

   Often grow in a shelf-like formation with overlapping clusters.

   Smooth, with no warts or scales.

   Usually white to light brown with firm, white flesh.

   The gills are white and are attached to and running down the cap and stem (decurrent).

2. Stem

   They may not have a stem. If they do it will often be stubby and off-center if the mushroom is growing on the side of a log. If it's growing on the top you will see a more well developed stem.

   No ring around the stem, and no sack around the base.

3. The flesh is white

Pleurotus ostreatus is easily recognized by the way it grows on wood in shelf-like clusters; its relatively large size; its whitish gills that run down a stubby, nearly-absent stem; and its whitish to lilac spore print. It appears between October and early April across North America, and features a brown cap.

A number of very similar species are closely related, including Pleurotus pulmonarius (which is often paler, and appears between late April and September), and Pleurotus populinus (which is found on the wood of quaking aspen).

Pleurotus ostreatus Health Benefits

Oyster mushrooms are used for various therapeutic medicinal purposes. Its wealth of nutrients and other powerful antioxidant compounds promote various alternative health benefits such as:

1. Builds immunity

   The compound ergothioneine leads the list of compounds in oyster mushrooms that promote better immune health. It helps in protecting the cells and in enhancing immune responses against infections.

2. Protects against infections

   Oyster mushrooms also have very powerful anti-microbial and antibacterial properties. The compounds the mushroom releases to digest organic material from nature and use it for food is also the same compounds that can help combat infections in the body.

   Another compound is benzaldehyde. It has powerful antibacterial actions.

3. Regulates cholesterol levels

   Oyster mushrooms can greatly help people who suffer from problems with high blood pressure and cholesterol levels. This mushroom is naturally low in sodium, an important dietary concern among those with high blood pressures.

   Statins are also abundant in oyster mushrooms. These compounds naturally lower the levels of cholesterol in the body. It acts just like the statin drugs used for lowering cholesterol.

These mushrooms are found on hardwoods. They secrete enzymes that break down the organic bonds in wood into smaller molecules. The carbon-hydrogen bonds in the wood are similar to those found in oil and pesticides. Thus due to their love of wood, oysters are also efficient in breaking down the organic bonds in toxic chemicals.

Oyster mushrooms are also powerful absorbers of mercury. Their mycelium channels mercury from the ground up into the mushroom itself. Once the mushroom is picked and destroyed, the mercury is removed from the environment.

Oysters naturally produce compounds called statins. Statin drugs reduce "bad cholesterol" (LDL) by stimulating receptors in the liver to clear the cholesterol from the body.

Specific polysaccharides, known as beta-D-glucans, are suspected to stimulate the immune system to fight cancer. The beta-D-glucan isolated from oyster mushrooms is called pleuran.

Pleurotus ostreatus Side Effects

Some people may be allergic to mushrooms and other types of fungi. If you experience any food allergy symptoms like hives, swelling, nausea, vomiting or cramps after eating oyster mushrooms, discontinue use and talk to your doctor.

Additionally, oyster mushrooms contain a very small amount of arabitol, a type of sugar alcohol that can cause trigger gastrointestinal symptoms in some people. If you find that you’re sensitive to sugar alcohols or following a diet plan low in FODMAPs, it may be best to limit your intake of oyster mushrooms.

Mushrooms also contain a good amount of purines, a compound that is broken down into uric acid in the body. High levels of uric acid can aggravate gout symptoms, such as pain, swelling, and redness in the joints. It may be helpful to limit your intake of purine foods if you have a history of gout or are experiencing a flare-up of symptoms.

Pleurotus ostreatus Extract

Extract of oyster mushroom is indicated for:

1. Various types of cancer especially liver cancer, breast cancer, Lymphoma, and colon cancer.

2. Liver functioning support and body detoxification. It nourishes and stimulates liver blood.

3. To improve the function of lymph nodes.

4. Metabolic syndrome (x syndrome).

5. To stimulate blood flow and drain excess moisture from blood vessels and dispenses cold.

6. Gout.

7. Hypercholesterolemia and hypertriglyceridemia. (hyperlipidemia)

8. Pre-menstrual pain (PMS) and irregular menstruation.

9. Migraines.

10. Gallstones and kidney stones.

11. Urinary tract infections and as a diuretic.

12. Prostatitis.

13. Arthritis.

14. The elderly to protect against diseases.

15. Depression, since it improves mood.

16. Diabetes type 2.

17. Candida and different fungi.

18. Intestinal inflammations and to cleanse the intestines and treat dyspepsia.

19. Body detoxification of heavy metals and accumulated toxins.

20. Hypotension.

21. Treatment and prevention of flu as a result of cold.

22. Impotence.

23. Allergy.

24. Chronic pain.

25. To moisten and soften tendons and ligaments.

26. Ulcers and boils.

27. Foot fungi.

28. Muscle weakness and Myasthenia.

Pleurotus ostreatus Medicinal Properties

This mushroom has statins and lovastatins that help in lowering cholesterol in the body. Cholesterol as a word was formed from the Greek language. Chole means bile; stereos means solid; and ol is a suffix derived from the word alcohol.

The Oyster Mushroom also has some bacteria-fighting substances. In 1950, pleuromutillin, an antibiotic developed from the mushroom, was found to kill various bacteria including the bacterium salmonella. Pseudomonas is another bacterium that pleuromutillin was able to wipe out.

More recent research, (Stamets, 2005) found that Pleurotus ostreatus, which are extracts from the Oyster Mushroom, are able to weaken the bacteria Staphylococcus aureus and Escherichia coli. From a concentration of 100 000 000 per milliliter, the bacterial concentration dropped to a mere 1 000 per milliliter within a span of 24-72 hours.

The Oyster Mushroom has the scent of anise because it has benzaldehyde. Benzaldehyde is an organic compound which is widely sought for industrial use. Martres, a Frenchman and pharmacist, was the first to extract this compound from a natural plant. He did that in 1803. Thereafter, in 1832, two German chemists, Friedrich Wohler, and Justus von Liebig, synthesized it. Because of its nice scent, pharmaceuticals use it a lot.

Pleurotus ostreatus Classification

Pleurotus mushroom was first studied in 1775 by Freiherr von Jacquin, a Dutch scientist. Freiherr ascribed it to the hat mushroom family.

In 1871 a German scientist named Paul Kummer determined that the Pleurotus – Oyster mushroom was an independent family with many species. The main cause of interest in this mushroom is due to its rich nutritional value as a high-quality substitute for animal protein.

Pleurotus ostreatus Polysaccharides

The polysaccharides found in mushrooms belonging to the genus Pleurotus have revealed important biological activities. Production of the mycelium biomass and polysaccharides (exopolysaccharides and internal polysaccharides) by P. ostreatus, in submerged culture, depends on the strains used, growth parameters, growth rhythm, as well as their nutritional requirements.

The fruiting body of P. ostreatus contains approximately 100 of different bioactive compounds, which mainly considered as a potential new source of dietary fiber.

Whereas, fungal cell wall are rich in non-starch polysaccharides, of which β-glucan are most interesting functional components and phenolic compounds such as protocatechuic acid, gallic acid, homogentisic acid, rutin, myrictin, chrysin, naringin, tocopherol like α-tocopherol and γ- tocopherol, ascorbic acid and β-carotene of each having their own outstanding medical effects (Wang et al. 2001 and Ferreira et al. 2009).

Moreover, they are healthy foods, rich in protein, lipids, carbohydrates, vitamin and minerals content but low in calories and fat content.

Pleurotus ostreatus Cultivation

1. Substrate preparation

   The substrate is milled to a length of about 2 to 6 cm. One of the most common substrates used for modern mushrooms is a mixture. This mixture of cotton-seed hulls and wheat straw has a higher water holding capacity than cottonseed hulls used alone. Pasteurization, used on some commercial mushroom farms, is carried out by filling the ingredients into revolving mixers, water is added to the desired level, and live steam is injected into the mixer while it is in operation.

2. Inoculation

   After completion of pasteurization (60 °C for 1 to 2 h), the substrate is cooled and spawned with the desired strain. At the time of spawning, a delayed-release supplement (rate of 3% to 10% of dry substrate weight) may be added to increase the yield and size of the mushroom production cycle.

3. Filling plastic bags with the substrate

   The pasteurized substrate is spawned and filled (from 25 to 30 lbs) into clear or black perforated polyethylene bags. Incubation The bags are incubated for 12 to 14 days at 25 °C and then transferred to the production room.

4. Mushroom production

   The mushroom begins to form around the edges of bag perforations. The bags are maintained under optimal temperature, moisture and other conditions for mycelium growth, and the conditions that favor fruiting. Mushroom shelves and suspended systems are the main systems used for Pleurotus cultivation. Studies on the mushroom cultivation on the use of different strains, different lignocellulosic substrates, different types of spawn, moisture, physicochemical conditions, etc. are important for the cultivation productivity of each particular mushroom.

5. Harvest

   The mushrooms are harvested from the substrate approximately 3 to 4 weeks after spawning depending on the strain, amount of supplement used, and temperature of spawn run.

Pleurotus ostreatus Growing

Pleurotus ostreatus is the second most cultivated edible mushroom worldwide after Agaricus bisporus. It has economic and ecological values and medicinal properties. Mushroom culture has moved toward diversification with the production of other mushrooms.

Particularly, P. ostreatus requires a shorter growth time in comparison to other edible mushrooms. The substrate used for their cultivation does not require sterilization, only pasteurization, which is less expensive.

Growing oyster mushrooms convert a high percentage of the substrate to fruiting bodies, increasing profitability. P. ostreatus demands few environmental controls, and their fruiting bodies are not often attacked by diseases and pests, and they can be cultivated in a simple and cheap way.

All this makes Pleurotus ostreatus cultivation an excellent alternative for the production of mushrooms when compared to other mushrooms.

Pleurotus ostreatus Taste

These mushrooms have a very mild flavor that, sometimes, tastes like button mushrooms when enjoyed raw.

However, when you cook oyster mushrooms you can enjoy a much wider range of delicious flavors. When cooked at very high heat they tend to be earthy, aromatic, a bit sweet, and, sometimes, they have a hint of an anise flavor.

To enjoy a more delicate flavor, try cooking your oyster mushrooms in a gentle sauté, which helps to bring out a briny flavor that can be outstanding.

Pleurotus ostreatus Nutrition Facts

One cup of raw oyster mushroom provides about 28 calories and 0.35 grams of fat, 2.85 grams of protein and 2 grams of fiber. The same amount provides 361 mg of potassium, 0.095 grams of Vitamin B6 and 33 µg of folate.

The nutrients found in the mushroom vary when accompanied with meat or bread. It could be sautéed, stir-fried or added to various dishes such as roast, stew, and salads.

Like many other types of mushrooms, oyster mushrooms can be consumed raw or cooked. In fact, simply sautéing them with a bit of oil and seasoning makes a delicious dish all on its own.

Recipe: Roasted Oyster Mushrooms

Ingredients:

1. 1/2 pound oyster mushrooms 230 grams

2. Salt

3. Pepper

4. Oil spray

If using the oven method:

1. Preheat your oven to 450 degrees F (230 degrees C).

2. While the oven preheats, prepare the mushrooms. Separate the bunches into individual mushrooms. Give them a gentle rinse and dry them with a paper towel. Use a knife to cut off and discard any dirty or tough parts on the stem end. If any of the mushrooms are much larger than bite-size, cut or tear them in half along the stem.

3. Prepare a baking sheet lined with aluminum foil. Spray a light coat of oil onto the foil. Place the mushrooms onto the foil. Spray a light coat of oil onto them and season them with salt and pepper.

4. When the oven is heated, place the baking sheet of mushrooms in the oven. Bake until the bottom side of the mushrooms is blistered and golden brown, about 12 minutes. Remove the baking sheet from the oven. Flip each of the mushrooms and return the sheet to the oven until the other side is golden, 8-10 minutes. Serve immediately.

If using the air fryer:

1. Preheat air fryer to 360 degrees F (180 degrees C) for 8 minutes.

2. Prepare the mushrooms as described above while the air fryer preheats.

3. When the air fryer has finished preheating, remove the basket from it. Spray a light coat of oil onto the grate surface of the basket. Place as many mushrooms as will fit in a single layer. Spray a light coat of oil onto the mushrooms and season them with salt and pepper.

4. Return the basket to the air fryer and cook at 360 F (180 C) until the mushrooms are nicely browned as shown in the photos, 8-10 minutes, flipping them once halfway through. Serve immediately.

Notes:

The smaller and thinner pieces will be crispier than the larger and thicker pieces (which will be juicier). I tore the mushrooms into large and small pieces to create variety (some crispy bits, some juicy ones).

If you want all your pieces to have a similar texture, try to tear (or cut) them into even-thickness pieces. It is possible to shred them thinly to achieve a texture similar to shredded chicken or pork.

Recipe: Oyster Mushrooms and Trout

Ingredients:

1. 4-6 oz yrout fillets

2. 1 1/2 Tbsp olive oil

3. 1 cup shallot, chopped

4. 8 oz button mushrooms, sliced

5. 4 oz oyster mushrooms, sliced

6. 1/3 cup light soy sauce

7. 1/3 cup dry sherry

8. 1/3 cup water

9. Black pepper (salt), to taste

Instructions:

1. In a large pan, heat oil and shallot over medium high heat. Cover, cook until shallot is tender. Add mushrooms. Continue cooking covered until mushrooms are soft.

2. Add soy sauce, sherry, and water. Simmer until sauce thickens slightly.

3. Remove from heat. Season with pepper and salt if desired. Set aside. Sauté trout, flesh side down over medium heat in lightly oiled pan 2-3 minutes.

4. Turn and cook until trout is opaque (about 3 minutes).

5. Serve with warm mushroom sauce.

Recipe: Oyster Mushroom Soup

Ingredients:

1. Makes 5 gallons

2. 2 sticks of butter

3. 4 or 5 large onions

4. 2 lbs carrots

5. 1 stalk celery

6. 6 lbs oyster mushrooms

7. 15 lbs potatoes

Instructions:

1. Peel and cook 15 lbs potatoes, mash to a creamy base.

2. Add 4 pints of cream to taste and to thicken.

3. Add vegetables and let simmer.

4. Add salt, pepper and parsley.

Recipe: Chicken (or fish) with Oyster Mushrooms

Ingredients:

1. 2 whole chicken breasts or 4 fish fillets

2. 6 Tbsp. of butter

3. 2 Tbsp. lemon juice

4. 1 garlic clove, peeled and minced

5. 1 medium onion, chopped

6. 1 pound oyster mushrooms

7. 1 cup white wine (dry)

8. 1/2 cup cream

Instructions:

1. Top chicken or fish each with 1/2 Tbsp. butter and lemon juice, broil until done. Melt 4 Tbsp. butter in skillet.

2. Add minced garlic and onion, saute about 5 minutes until tender.

3. Add mushrooms and saute 5 minutes more.

4. Add wine and cream, and reduce for about 5 minutes. Pour reduced sauce over chicken or fish. Season to taste.

Recipe: Pork with Oyster Mushrooms

Ingredients:

1. 12 oz. pork fillet

2. 1 large red onion

3. 12 oz. Oyster Mushrooms

4. 6 oz. cream

5. Salt and pepper to taste

6. Olive oil for frying

Slice pork, onions and mushrooms into thin strips. Saute pork until just cooked, add onions and mushrooms and fry until cooked through. Season, then add cream, reduce and serve.

Recipe: Oyster Mushroom Fettuccini

Ingredients:

1. 6 oz. Oyster mushrooms, or a variety of mushrooms

2. 1 pkg. Fettuccini

3. 3 Tbsp. extra virgin olive oil

4. 3 cloves garlic, minced

5. 1/2 cup pine nuts

6. 1 pkg. (3 oz.) sun dried tomatoes, softened and minced

Cook fettuccini according to package instructions. In medium sauce pan, heat oil and saute remaining ingredients for 2-3 minutes. Toss with hot, cooked fettuccini.