Nostoc flagelliforme, pronounced as Fat Choi in Chinese, is a popular dish at Lunar New Year's Eve dinners. It is similar to dried fat, but becomes silky when cooked. Its name sounds like "make a fortune" in Cantonese, making it a popular dish during the festival A favorite. However, are there any health benefits to eating black moss?
Name and biological classification
name
Chinese pronunciation is: fat choy; "fat" means "hair" in Chinese , and "choy" means "dish" in Chinese
English name: Black moss;
Scientific name: Nostoc flagelliforme (2016); Nematonostoc flagelliforme (1934); Nostoc commune var. flagelliforme (1886)
biological classification
Nostoc is classified as
- bacterial domain
- Cyanobacteria
- Class Cyanobacteria
- Candidales
- Candidaceae
- Nostoc
- Nostoc species
Appearance description
Nostoc is a filamentous algae that grows near deserts, forming spherical clusters that stick to the surface. After drying, it looks like messy brown and black hair.
Ecology
It is found in arid or semi-arid steppes, deserts, and plateaus of Algeria, China, the former Czechoslovakia, France, Mexico, Mongolia, Morocco, Russia, Somalia, and the United States .
The study found 421 propylated lysine residues in 236 different proteins in Nostoc. These malonylated proteins are highly enriched in multiple metabolic pathways, including carbon metabolism and photosynthesis. The role of malonylation in Nostoc is thought to be responsible for the drought tolerance mechanism of this organism [1].
Nostoc can be propagated in three ways: single cell division to form new colonies, spore propagation and separation of algal fragments to produce new algae, and formation of unbranched algal cells. Nitrogen fixation occurs in specialized cells called heterocysts, which develop at distances along thin filaments. When many filaments come together, they form a gel-like object visible to the naked eye. These algae multiply quickly and accumulate in piles. Once collected and dried, they become the familiar Nostoc.
A terrestrial creature. Producing long-term cultures in a laboratory setting has proven difficult, if not impossible.
Conservation and supervision
Nostoc is a rare desert algae found in the grasslands of northwestern China and is the only cyanobacteria that thrives in nitrogen-deficient areas. It has many advantages such as nitrogen fixation (providing nutrients for plants on barren land), high and low temperature resistance, and drought tolerance. And it can also absorb inorganic carbon and nitrogen and generate organic carbon and nitrogen. In addition, the growth of Nostoc helps prevent wind and sand damage, prevent soil desertification, and significantly contributes to improving desert soil quality and promoting the growth of other organisms.
Nostoc is popular in Guangdong because its homophonic meaning means "getting rich", prompting destructive harvesting practices. Massive desertification is believed to have caused the country's dust storms since the 1980s.
Due to the challenges of artificial cultivation of Nostoc and its slow growth, it takes decades to mature and can only be collected once. This species is on the verge of exhaustion . In order to protect its ecological significance in desert areas, China has listed Nostoc as an endangered species in 2000. It belongs to the list of national first-level protected wild plants and prohibits the collection, acquisition, processing, sales and Export[2].
Nutritional value
Nostoc is generally considered to be nutritious and has cooling properties. It is low in fat and cholesterol and high in protein and carbohydrates. Due to its iron content, it is also thought to aid in the production of blood cells.
Health benefits
Nostoc flagelliforme offers various health benefits across different products. Research shows that Nostoc flagelliforme can be utilized in food products to create bowel-moistening, constipation-relieving foods rich in nutrients and effective ingredients [3].
Additionally, the production of Nostoc flagelliforme and glutinous rice wine provides a fragrant, sweet, and mellow beverage that is rich in minerals, vitamins, and antioxidants, offering benefits such as oxidation resistance, immunity improvement, and skin moisturizing [4].
Furthermore, incorporating Nostoc flagelliforme into wine production enhances its health-preserving effects, including lowering blood sugar and blood fat, resisting aging, viruses, and bacteria, and regulating the immune system [5].
Moreover, the inclusion of Nostoc flagelliforme cells and exopolysaccharides in biscuits not only improves flavor but also boosts immunity, fights tumors, reduces blood lipid and sugar levels, and enhances overall health [6].
Controversy
However, researchers at the Chinese University of Hong Kong found that nostoc has no nutritional value and can actually affect neurological function. It contains a toxic amino acid called beta-methylamino-L-alanine (BMMA), which can cause degenerative diseases such as Alzheimer's, Parkinson's and dementia. In addition, Nostoc is difficult to digest. Therefore, especially infants, young children and pregnant women, consumption should be limited.
Summary
Investigations show that the market is full of counterfeit products. Whether it is real or fake, Nostoc has no edible value or nutritional value, and eating it will have a negative impact on the ecological environment. It is recommended to completely stop eating Nostoc and educate the elderly to avoid buying Nostoc because of the homophonic sound.
References
[1] Wang, M., Zhu, Q., Yao, N., Liang, W., Ma, X., Li, J., Li, X., Wang, L., & Liang, W. (2023 ). The Enzyme Lysine Malonylation of Calvin Cycle and Gluconeogenesis Regulated Glycometabolism in Nostoc flagelliforme to Adapt to Drought Stress. International Journal of Molecular Sciences, 24(9), 8446. https://doi.org/10.3390/ijms24098446
[2] Central People's Government of the People's Republic of China. State Council (June 14, 2000). Notice of the State Council on Prohibiting the Collection and Sale of Nostoc and Indiscriminate Digging of Licorice and Ephedra. State Council Gazette. [Guofa [2000] 13 No.] https://www.gov.cn/gongbao/content/2000/content_60307.htm
[3] Xiaolong, Yuan., Jing, An., Tao, Zheng., Wenjian, Liu. (2022). Exogenous melatonin improves salt tolerance mainly by regulating the antioxidant system in cyanobacterium Nostoc flagelliforme. PeerJ, doi: 10.7717/peerj.14479
[4] Yang, Chunmei., Yang, Haijun., Liu, He., Yang, Lina., Yang, Haibing., Yang, Haiyan. (2018). A bowel-moistening constipation-relieving food containing nostoc flagelliforme and its preparation method.
[5] Guo, Jinying., Hu, Juanjuan., Cui, Guoting., Ren, Guoyan., Wu, Ying., Chen, Xiujin., Wang, Ping., Han, Sihai., Li, Zhaozhou., Li, Songbiao. (2016). Production method of Nostoc flagelliforme and glutinous rice wine.
[6] Guo, Jinying., Li, Tonghui., Sun, Junjie., Zhu, Beiru., Li, Songbiao., Wang, Ping., Zhang, Min., Zhang, Yuxian. (2014). Nostoc flagelliforme wine and preparation method thereof.