Maitake Mushrooms and Polysaccharides Extraction

According to an old Japanese legend, there was once a group of Buddhist nuns who went out into the forest searching for food. Monastic living is often simple, but these nuns had fallen on particularly hard times. They needed to find something to eat in that forest, or they may not survive. While on this foraging mission, they came across a small batch of mushrooms nestled amongst the undergrowth. Delicious to the taste, and extremely rare, these mushrooms made the nuns so happy they are said to have danced with joy upon their discovery. From that point on, these mushrooms were called “Maitake” which translates to “The Dancing Mushroom” in Japanese. [1] 

Over the last several millennia, these mushrooms remained popular in China and Northern Japan for both culinary and medicinal reasons. These two motivating factors kept demand high, but these mushrooms remained hard to find in the wild. All of this changed in the 1990s, when new agricultural techniques allowed Japanese fungi culturists to start cultivating maitake mushrooms indoors. [2] These developments led to industrial scale production that has dramatically changed the maitake market. 

Beyond the ability to consistently match demands with a consistent supply, farms can also minimize variables between harvests to ensure consistency of product. As a result the emphasis shifted to quality of products, resulting in a need for better extraction techniques. Experimentation with new solvents and strategies led to improved yields, and it only takes a few simple alterations. It has taken centuries to get to this point, which may provide a new reason to dance.

What Benefits do Maitake Mushrooms Provide?

Maitake mushrooms may have started out as “The Dancing Mushroom” but they soon earned a second nickname: The King of Mushrooms. This “King” status could be a reference to their centuries of popularity, or to the numerous benefits that they provide to humans. Another possible explanation could be their size. In the wild, maitake mushroom clusters can grow to weigh up to 100 lbs. This explains the nuns’ excitement, as early consumers would certainly appreciate the amount of edible material these mushrooms provided. Without realizing it, they were also introducing a food source that is saturated with vitamins and nutrients that play a vital role in dietary health. [3] 

Maitake mushrooms provided a good source of:

• Proteins,
• vitamins B and D,
• Copper,
• Zinc
• Phosphorus. 

Having all these ingredients in one food may not matter today, considering the large selection at most supermarkets. But this was not the case in the predominantly agrarian societies of ancient China and Japan, where food was limited to the crops you grew and the animals you raised. Maitake mushrooms provided a valuable staple to these young societies, and users soon began to report medicinal benefits as well. 

The first recorded use in traditional Asian medicine for these mushrooms was to treat indigestion. [4] Later, other practitioners found this fungi to be helpful with calming nerves. [5] These mushrooms are non-psychoactive, and thanks to modern analytic technology, individual ingredients are being identified and isolated to provide relief for people in need. While those dietary nutrients are valuable, maitake mushrooms have two key ingredients. The first is a high proportion of antioxidants. [6]

Antioxidants prevent the oxidation effect of free radicals, which benefits numerous systems throughout the body. [7] Specifically, the lowering of free radicals has been associated with improvements in regulating blood sugar, preventing heart disease, and boosting long term immunity. [8][9][10] When considering an even lengthier timeline, antioxidants even have a positive correlation with combating cancer. [11] 

Antioxidants are certainly valuable for their health benefits, but they can be found in a variety of food sources. Maitake mushrooms are particularly known for another compound that is common across multiple other food sources, but one that this mushroom produces in a special way. What really makes maitake mushrooms so special is their richness in polysaccharides.

What are Polysaccharides, and Why do they Matter?

Sugar comes in many forms. The simplest are called monosaccharides, and they are made up of single sugar molecules. The other simple sugars are called disaccharides, and as the name suggests they are made up of two sugar molecules. These sugars are easy to digest, and make up common ingredients like lactose in milk, fructose in fruit, or the basic sugar glucose. Identified by their sweet taste,  these sugars tend to be metabolized quickly, which leads to both a sudden energy burst followed by a crash. This is because these sugar molecules can’t be broken down into smaller units, limiting the energy they provide. 

Polysaccharides, on the other hand, are more complex sugars that are made up of numerous smaller units of monosaccharides and disaccharides. [12] Unlike their sweeter constituents, polysaccharides are carbohydrates that are found in grains, starches, and certain vegetables like corn. Their molecular complexity is what gives polysaccharides from maitake mushrooms their nutritional value. Polysaccharides take longer to digest, which gives the body more time to absorb any additional resources within the botanical material. [13]

This extended digestion period may help to explain how maitake mushrooms relieve indigestion, but it also can play a role in treating type II diabetes by helping to regulate blood sugar. [14] Since polysaccharides take longer to break down, they don’t result in blood sugar spikes like simple sugars, helping to create a baseline throughout the day. In addition to diabetes, this may become a fact in treating other metabolic disorders, and could even help to prevent obesity. [15]

This is because carbohydrates from maitake mushrooms have fewer calories than other carbohydrates when comparing equivalent weights. Maitake has half the calories of potatoes, one quarter of the calories of pasta, and 10% of the calories in bread. To help this process even further, polysaccharides are also easier to digest than other carbohydrates thanks to the Humans are also better equipped to process the high concentration of fiber. [16]

Fiber aids the digestive process, and also adds the the association these mushrooms have with indigestion relief, but for a surprising reason. Polysaccharides from maitake mushrooms provide a type of fiber that does not digest completely, and is instead fermented to assist the digestion.[17] 

The ethanol produced feeds the microbiota in the gut, which plays an essential role in multiple processes throughout the body. Specifically, this could contribute to additional immune system benefits or detoxification through the liver and kidneys.[18] Research is still early, but data suggests that the gut’s microbiota may also provide hypolipidemic activity and could go as far as providing anti-tumor effects. [19][20] This is what makes polysaccharides from maitake mushrooms so prized. Lower calories, extended nutrient absorption, antioxidants, and fiber promoted these mushrooms for centuries. 

Listing the key ingredients doesn’t sound like much, but when totaling the medical maladies they may help to treat, maitake mushrooms are impressive. What became obvious very quickly was that traditional extraction techniques were not good enough to maximize the value these mushrooms provide. As the market changed, so did the extraction industry.

How to Improve Maitake Mushroom Extraction?

Though maitake mushroom clusters can grow to large sizes, they are often difficult to locate in their natural environment. To provide a more consistent supply, Japanese farmers began employing sustainable agricultural practices to develop indoor growing techniques for these mushrooms.[21] This domestication not only stabilized the supply, but also provided quality control from one harvest to another. 

By removing external variables, researchers began to evaluate the potency of polysaccharides being extracted from the maitake. What they found surprised them. Traditionally, polysaccharide extraction from maitake mushrooms was usually accomplished using hot water as a solvent. This is a form of maceration that results in either a tincture or food stock that could then be employed in a variety of ways.

By examining compounds like proteins, lipids, and pigments in the polysaccharide extracts, the researchers believed it was possible that maitake mushrooms are susceptible to heat.[22] To determine how much of a role temperature played in degrading the molecular material, this was the first aspect to change. To test the temperature variable, hot water extraction was replaced with cold water extraction. [23] This led to positive results, but it may not be the only variable degrading the organic material. 

The next question to be addressed was whether or not maitake mushroom components are water-soluble. This led to experiments using supercritical CO2 extraction, which improved yields even further. [24] Supercritical CO2 has the added benefit of also avoiding heat by increasing pressure. Carbon dioxide not only limited molecular depredation, but CO2 is more recyclable than water. Both of these techniques improved extractions over the traditional maceration, but this was not the last trick researchers could employ. 

Using ammonium sulfate ethanol as a solvent, aqueous two phase extraction systems (ATPS) are providing some of the most promising results yet. [25] ATPS rely on physical properties of the solution to allow a mixing period followed by a separation period through the introduction of a catalyst. This can result in faster extractions while using less energy.

While all of these extraction methods, including maceration, are still being employed today, maitake mushroom polysaccharides typically need to go through one final step before they are suitable for consumption. This involves a purification method involving ethyl alcohol deposition and column chromatography. [26]

This final processing stage separates any other undesirable plant materials from the polysaccharide extracts providing a purity previously unknown to Maitake products. This ensures that no matter what extraction method manufacturers prefer, their polysaccharides can provide users with the most benefits possible. All of these options are viable, but variables like costs, solvents, and intended use will all play a role in determining which extraction method is preferred.

References:

1. Halpern, Georges M. “Medicinal mushrooms.” Progress in Nutrition 12.1 (2010): 29-36.
2. Mayuzumi, Yoshikazu, and Takashi Mizuno. “III. Cultivation methods of maitake (Grifola frondosa).” Food Reviews International 13.3 (1997): 357-364.
3. Kabir, Yearul, Mami YAMAGUCHI, and Shuichi KIMURA. “Effect of Shiitake (Lentinus edodes) and Maitake (Grjfola frondosa) mushrooms on blood pressure and plasma lipids of spontaneously hypertensive rats.” Journal of nutritional science and vitaminology 33.5 (1987): 341-346.
4. OHTSURU, Masaru, Hiroyuki HORIO, and Hironori MASUI. “Angiotensin I-Converting Enzyme Inhibitory Peptides from Pepsin Digest of Maitake (Gnfola frondosa).” Food Science and Technology Research 6.1 (2000): 9-11.
5. Mizuno, Takashi, and Cun Zhuang. “Maitake, Grifola frondosa: pharmacological effects.” Food Reviews International 11.1 (1995): 135-149.
6. Yeh, Jan-Ying, et al. “Antioxidant properties and antioxidant compounds of various extracts from the edible basidiomycete Grifola frondosa (Maitake).” Molecules 16.4 (2011): 3197-3211.
7. Pham-Huy, Lien Ai, Hua He, and Chuong Pham-Huy. “Free radicals, antioxidants in disease and health.” International journal of biomedical science: IJBS 4.2 (2008): 89.
8. Konno, Sensuke. “Maitake SX-fraction: Possible hypoglycemic effect on diabetes mellitus.” Alternative & Complementary Therapies 7.6 (2001): 366-370.
9. Pashkow, Fredric J. “Oxidative stress and inflammation in heart disease: do antioxidants have a role in treatment and/or prevention?.” International journal of inflammation 2011.1 (2011): 514623.
10. Vetvicka, Vaclav, and Jana Vetvickova. “Immune-enhancing effects of Maitake (Grifola frondosa) and Shiitake (Lentinula edodes) extracts.” Annals of translational medicine 2.2 (2014).
11. Masuda, Yuki, et al. “Antitumor activity of orally administered maitake α-glucan by stimulating antitumor immune response in murine tumor.” PLoS One 12.3 (2017): e0173621.
12. Sun, Naxin, Yana Zhao, and Mingyuan Yin. “Extraction, purification, structure and bioactivities of polysaccharides from Grifola frondosa (maitake): a review.” Journal of Food Measurement and Characterization 17.6 (2023): 6200-6213.
13. Niaz, Kamal, Fazlullah Khan, and Muhammad Ajmal Shah. “Analysis of carbohydrates (monosaccharides, polysaccharides).” Recent advances in natural products analysis. Elsevier, 2020. 621-633.
14. Chowdhury, Pritha, and Santanu Paul. “The potential role of mushrooms in the prevention and treatment of diabetes: A review.” Journal of Biologically Active Products from Nature 10.5 (2020): 429-454.
15. Mustafa, Faheem, et al. “Edible mushrooms as novel myco-therapeutics: effects on lipid level, obesity, and BMI.” Journal of Fungi 8.2 (2022): 211.
16. Huang, Shih-Jeng, et al. “Nonvolatile taste components of culinary-medicinal maitake mushroom, Grifola frondosa (Dicks.: Fr.) SF Gray.” International Journal of Medicinal Mushrooms 13.3 (2011).
17. De Giani, Alessandra, et al. “Positive modulation of a new reconstructed human gut microbiota by Maitake extract helpfully boosts the intestinal environment in vitro.” Plos one 19.4 (2024): e0301822.
18. Kodama, Noriko, Tadahiro Kakuno, and Hiroaki Nanba. “Stimulation of the natural immune system in normal mice by polysaccharide from maitake mushroom.” Mycoscience 44 (2003): 257-261.
19. Lei, Hong, et al. “Hypoglycemic and hypolipidemic activities of MT-α-glucan and its effect on immune function of diabetic mice.” Carbohydrate polymers 89.1 (2012): 245-250.
20. Deng, Gary, et al. “A phase I/II trial of a polysaccharide extract from Grifola frondosa (Maitake mushroom) in breast cancer patients: immunological effects.” Journal of cancer research and clinical oncology 135 (2009): 1215-1221.
21. Yamanaka, Katsuji. “I. Production of cultivated edible mushrooms.” Food reviews international 13.3 (1997): 327-333.
22. Choi, Y., et al. “Influence of heat treatment on the antioxidant activities and polyphenolic compounds of Shiitake (Lentinus edodes) mushroom.” Food chemistry 99.2 (2006): 381-387.
23. Sharpe, Erica, et al. “Comparison of antioxidant activity and extraction techniques for commercially and laboratory prepared extracts from six mushroom species.” Journal of agriculture and food research 4 (2021): 100130.
24. Sun, Naxin, Yana Zhao, and Mingyuan Yin. “Extraction, purification, structure and bioactivities of polysaccharides from Grifola frondosa (maitake): a review.” Journal of Food Measurement and Characterization 17.6 (2023): 6200-6213.
25. Hiwatashi, Kazuyuki, et al. “Purification and characterization of a novel prolyl aminopeptidase from Maitake (Grifola frondosa).” Bioscience, biotechnology, and biochemistry 68.6 (2004): 1395-1397.
26. Sezgin, Sema, Abdullah Dalar, and Yusuf Uzun. “Determination of antioxidant activities and chemical composition of sequential fractions of five edible mushrooms from Turkey.” Journal of food science and technology 57 (2020): 1866-1876.