Tremella fuciformis is wildly grown in Fujian, Sichuan, Guizhou, Zhejiang, Hubei provinces in China.

Tremella fuciformis is a kind of fungus and is commonly found on the wilted branches of broadleaf trees.

Light, temperature and humidity are essential in the growth of Tremella fuciformis. The optimum temperature for the growth of Tremella fuciformis is from 22 to 25℃. In different growth stages, Tremella fuciformis needs different humidity, and the optimal water content of the culture materials is usually from 55% to 60%. If the water content reaches 65%, Tremella fuciformis can rot easily. Scattered light is beneficial to the production of high quality Tremella fuciformis, and the fruit bodies of Tremella fuciformis develop normally at 50 lux.

At present, the main production methods of Tremella fuciformis are basswood cultivation and bagged substrate cultivation. As the traditional method, basswood cultivation has a long production phase and low yield, but the quality of the produced Tremella fuciformis is very good^[1] 上官端琳, et al.”我國銀耳段木栽培技術研究現狀.” 食用菌 42.02(2020):1-3.. Bagged substrate cultivation uses other substrates instead of basswood to plant Tremella fuciformis^[2] 孫治民,蔣學傑.”銀耳代料栽培技術.” 特種經濟動植物 24.03(2021):43-44..

Tremella fuciformis is soft and white, translucent and elastic, with fluffy and hollow patches, and its appearance is like a blooming chrysanthemums. Soup made of Tremella fuciformis is crystal clear and sticky. It tastes soft, waxy, delicate and sweet, with a light and pleasant fragrance.

Figure 1: Tremella fuciformis cultivated by bagged substrate cultivation method.

Figure 2: Tremella fuciformis after processing.

Tremella fuciformisis a valuable nutritional tonic. In the ancient Chinese dynasties, the royal aristocracy regarded Tremella fuciformis as a life-prolongation product. Tremella fuciformis  has a long consumption history in China and is known as “the King of mushrooms”. Tremella fuciformis is one of the ‘Wu Er’ (Five fungus) described in the ‘The Divine Farmer’s Classic of Materia Medica, Shen Nong Bencao Jing’ about 2,000 years ago. It is recorded in the “Compendium of Materia Medica” that ‘it is white as silver, and like chrysanthemums and comb in shape. It grows on ancient trees. It tastes sweet, and it can clear lung heat, tonify kidney dryness, strengthen mind, and invigorate qi and blood’. According to the “Materia Medica New”, Tremella fuciformis has the effect of nourishing lungs and Yin. It is recorded in the “Herbal Poetry Antidote Medicine Note” that Tremella fuciformis “can treat mouth dryness, lung dysfunction, phlegm deposition and cough” ^[3] 薛蔚.”銀耳多醣提取純化技術及功能性質探究.” 南方農業 14.21(2020):141-142.. Besides China, countries around the world such as Japan and Southeast Asian countries have the tradition of eating Tremella fuciformis as well ^[4] Zhou, Yalin, et al. “Immunomodulatory effect of tremella polysaccharides against cyclophosphamide-induced immunosuppression in mice.” Molecules 23.2 (2018): 239.. In recent years, the sales of Tremella fuciformis have gradually expanded to Western Europe, North America and other regions, and its excellent health care functions are valued by people all over the world.

Tremella fuciformisis a traditional edible and medicinal fungus with biological activities and pharmacological effects such as enhancing immunity, anti-cancer, anti-aging, anti-inflammatory, lowering blood sugar, improving digestion, and anti-diarrhea. Modern medication has proved that the main active ingredient of Tremella fuciformis is Tremella fuciformis polysaccharides^[5] Zheng, Qianwang, et al. “Structural Analysis and Antioxidant Activity of Extracellular Polysaccharides Extracted from Culinary− Medicinal White Jelly Mushroom Tremella fuciformis (Tremellomycetes) Conidium Cells.” International Journal of Medicinal Mushrooms 22.5 (2020)., which account for 60% to 70% of the dry weight of Tremella fuciformis. In addition, Tremella fuciformis also contains protein, fat and a variety of amino acids, mineral and other substances, which enable Tremella fuciformis to strengthen the human body.

1. Polysaccharides

Tremella fuciformis polysaccharides have a wide range of biological activities and functions, including anti-aging^[6] Xu, Wenqing, et al. “Protective effect of polysaccharides isolated from Tremella fuciformis against radiation-induced damage in mice.” Journal of radiation research 53.3 (2012): 353-360., anti-oxidation^[7] Chen, Bin. “Optimization of extraction of Tremella fuciformis polysaccharides and its antioxidant and antitumour activities in vitro.” Carbohydrate Polymers 81.2 (2010): 420-424., anti-tumor^[8] Yang, Dandan, Yong Liu, and Lijuan Zhang. “Tremella polysaccharide: The molecular mechanisms of its drug action.” Progress in molecular biology and translational science 163 (2019): 383-421., anti-inflammatory^[9] UKAI, SIGEO, et al. “Polysaccharides in fungi. XIV. Anti-inflammatory effect of the polysaccharides from the fruit bodies of several fungi.” Journal of Pharmacobio-dynamics 6.12 (1983): 983-990., reducing blood glucose^[10] Bach, Erna Elisabeth, et al. “Use of polysaccharide extracted from Tremella fuciformis berk for control diabetes induced in rats.” Emirates Journal of Food and Agriculture (2015): 585-591. and improving immunity^[11] Wu, Yu-ji, et al. “Structure, bioactivities and applications of the polysaccharides from Tremella fuciformis mushroom: a review.” International journal of biological macromolecules 121 (2019): 1005-1010.. Tremella fuciformis polysaccharides can promote nucleic acid and protein synthesis, increase the content of cytochrome P-450 in liver microsomes, and enhance the immune function of the body to delay aging. In addition, Tremella fuciformis polysaccharides have antioxidant function as they can significantly enhance the activity of superoxide dismutase (SOD) in the brain and liver tissue of mice, and inhibit the activity of enzymes positively related to aging in the brain. As a biological immune response regulator, Tremella fuciformis polysaccharides indirectly inhibit or kill tumor cells by enhancing the immune function of the body, and thus play an anti-tumor role. It was found that Tremella fuciformis polysaccharides significantly inhibited the formation of stress ulcer in rats, promoted the healing of ulcer, and had anti-inflammatory and anti-swelling effects. Tremella fuciformis polysaccharides can also regulate sugar metabolism enzymes, and lower blood sugar by accelerating blood sugar transformation and slowing down glucose absorption. In addition, Tremella fuciformis polysaccharides promote the hematopoietic function of the bone marrow, enhance human immunity through mobilizing lymphocytes, and strengthening the phagocytosis of white blood cells.

2. Amino acids and micro minerals

Tremella fuciformis can provide a lot of essential micro elements for the human body and improve various functions of the human body ^[12] Shahrajabian, M. H. , et al. “Chemical compounds and health benefits of Tremella, a valued mushroom as both cuisine and medicine in ancient China and modern era.” (2020).. According to the nutritional analysis, Tremella fuciformis contains a total of 17 kinds of amino acids, of which 7 kinds are essential amino acids that are necessary for the human body. Tremella fuciformis is rich in mineral elements, with 357 milligrams of calcium and 30.4 milligrams of iron in per 100g of Tremella fuciformis.

3. Dietary Fibers

Dietary fibers are another kind of nutrients in Tremella fuciformis besides polysaccharides and proteins. Dietary fibers can promote gastrointestinal peristalsis and improve digestion. The plant gum contained in Tremella fuciformis can inhibit the abnormal peristalsis of the gastrointestinal tract, thus enable Tremella fuciformis to promote defecation. However, Tremella fuciformis also has anti-diarrhea effect ^[13] Cheung, and C. K. Peter . “Mini-review on edible mushrooms as source of dietary fiber: Preparation and health benefits.” Food Science & Human Wellness 2.3-4(2013):162-166..

Tremella fuciformis is a common food ingredient in our daily life. Its processing methods are simple and economical, mainly including sun-drying and oven drying. Sun-drying is very straightforward, but it is only suitable for small-scale production. Oven drying method is more suitable for mass production, and clean Tremella fuciformis are dried in the oven at 40℃ to 60℃ for 6 to 10 hours.

Tremella fuciformis tastes sweet, flat and has no toxicity. It can not only improve human immunity, but also have the effect of nourishing the lung. It has been a healthcare delicacy since ancient times, and has a long consumption history worldwide. So far, no obvious toxicity and side effects have been reported. Tremella fuciformis is rich in natural phyto-gum and has the effect of nourishing Yin. Besides China, Japan, Taiwan (China) and South Korea also have cultivated a small amount of Tremella fuciformis, mainly for use in daily healthcare and beauty enhancement. In the United States, there is no regulation on Tremella fuciformis, and it can be sold over-the-counter ^[14] S. Rajarathnam, M.N. Shashirekha, ‘MUSHROOMS AND TRUFFLES | Use of Wild Mushrooms,’ Encyclopedia of Food Sciences and Nutrition (Second Edition), 2003：4048-4054.. So far, no obvious toxicity and side effects of Tremella fuciformis have been reported in any randomized controlled clinical trials ^[15] Ban, Soonhyun, et al. “Efficacy and safety of Tremella fuciformis in individuals with subjective cognitive impairment: A randomized controlled trial.” Journal of medicinal food 21.4 (2018): 400-407.. Therefore, Tremella fuciformis is a kind of healthcare food ingredient which can be taken safely for a long period of time.