Kappaphycus alvarezii (Eucheuma Cottonii) is an exotic, invasive seaweed that grows in the subtidal zone (below the low tide line) of East Asia, the Pacific Ocean, Malaysia, the Philippines, Indonesia, the Caribbean on rocky areas of the seabed and on sand near coral reefs, where waves take on a regular slow motion and the water is shallow. This sea moss is also found on the rocky coasts of North America and Europe. It has been used as a medicine by the Irish since 1800.
Like the Euchema plant species that grow on land, this algae, which takes on a yellowish to amber colour, has an apical offshoot that can divide to give rise to the growth of new branches. The life cycle is triphasic.

Its main components are carrageenan, the third most important hydrocolloid after starch and gelatine and used extremely widely by the food industry as a gelling and stabilising agent (κ-carrageenan), and potassium salt.

Botanical Classification

Kingdom: Plantae
Clade: Rhodophyta
Class: Florideophyceae
Order: Gigartinales
Family: Solieriaceae
Genus: Kappaphycus
Species: K. alvarezii

Plant Characteristics

Kappaphycus alvarezii thrives in shallow, calm waters, preferably in areas with abundant sunlight. It has a robust, fleshy body structure, typically ranging in color from green to reddish-brown. The algae form dense clumps and can reach considerable sizes under optimal conditions.

Chemical Composition and Structure

This algae is rich in carrageenan, a family of linear sulfated polysaccharides with strong gelling properties. Besides carrageenan, it contains various essential nutrients such as vitamins, minerals, and antioxidants, making it useful in various nutritional and therapeutic contexts.

How to Cultivate It

Cultivating K. alvarezii is primarily an aquaculture activity:

1. Water: Requires clean, calm waters with temperatures ranging from 20 to 30 degrees Celsius.
2. Planting: Commonly propagated through cuttings, with young plants tied to floating ropes anchored to the seabed.
3. Care: Regular monitoring to prevent diseases and pests; harvesting every 45-60 days to maximize production.
4. Harvest: The algae is harvested by cutting near the base to allow for rapid regeneration.

Uses and Benefits

The algae is primarily used for carrageenan production, utilized in numerous food products such as dairy and processed meats, in cosmetics for its thickening and moisturizing properties, and in medical applications for its ability to promote wound healing and reduce inflammation.

Applications

• Food: Carrageenan as a gelling agent, stabilizer, and emulsifier.
• Cosmetics: Used in formulas for creams and lotions for its moisturizing and film-forming properties.
• Medical: Potential use in bioactive dressings and as a natural anti-inflammatory.

Environmental and Safety Considerations

Cultivation of K. alvarezii must be managed carefully to avoid negative impacts on local marine ecosystems, such as eutrophication and competition with native marine species. Sustainable cultivation practices and environmental monitoring are crucial. The algae is considered safe for human consumption and use in cosmetics, but its cultivation must follow strict quality standards to prevent contamination.

What it is used for and where

Medical

Countries such as China, Korea and Japan show an increasing consumption of seaweed which, compared to Western countries, is correlated with a relatively low incidence of metabolic and cardiovascular disorders (1).
Numerous studies have looked at Kappaphycus algae as a functional food, showing that this algae can reverse the metabolic syndrome through selective inhibition of obesogenic gut bacteria and promotion of gut bacteria that improve the healthy state of the human body (2), it may be able to slow down the growth rate of cancer cells (3).
Other notable applications of this alga include its use to reduce cholesterol (4) and its antiviral properties (5).
Other studies have investigated the active fraction of Kappaphycus alvarezii as a potential candidate for the treatment of diabetes (6).

Cosmetics

The scientific literature has also dealt with the possible applications of Kappaphycus alvarezii for skin care. Kappaphycus alvarezii has been shown to develop a film-forming effect that protects the epidermis by reducing wrinkles, skin desquamation and reducing transepidermal water loss.(7).

Kappaphycus alvarezii studies

References_________________________________________________________________________

(1) Yoneda M, Yamane K, Jitsuiki K, Nakanishi S, Kamei N, Watanabe H, Kohno N. Prevalence of metabolic syndrome compared between native Japanese and Japanese-Americans. Diabetes Res Clin Pract. 2008 Mar;79(3):518-22. doi: 10.1016/j.diabres.2007.10.012.

Abstract. Metabolic syndrome is a condition characterized by the accumulation of multiple risk factors for atherosclerosis. Japanese-Americans in the U.S. have a more rapid and intense progression of atherosclerosis than native Japanese in Japan due to a westernization of their lifestyle. We investigated the prevalence of metabolic syndrome between 416 native Japanese (194 men and 222 women) in Hiroshima and 574 Japanese-Americans (217 men and 357 women) in Los Angeles, aged 30-89 years. According to the criteria proposed by the Japanese Society of Internal Medicine, the prevalence was 13.9 and 2.7% for native Japanese men and women, and 32.7 and 3.4% for Japanese-American men and women, respectively. According to the IDF or AHA/NHLBI criteria, the prevalence was 20.1 and 6.3%, and 38.7 and 4.5%, or 13.4 and 14.4%, and 30.9 and 27.7%, respectively. Thus, the prevalence of metabolic syndrome in men was significantly higher in Japanese-American than in native Japanese by all the three criteria. However, the prevalence in women was similar between native Japanese and Japanese-American by the Japanese and IDF criteria, whereas it was significantly higher in Japanese-American than in native Japanese by the AHA/NHLBI criteria. This report demonstrates that a westernization of lifestyle can increase the prevalence of metabolic syndrome among Japanese-Americans as compared to native Japanese.

(2) Wanyonyi S, du Preez R, Brown L, Paul NA, Panchal SK. Kappaphycus alvarezii as a Food Supplement Prevents Diet-Induced Metabolic Syndrome in Rats. Nutrients. 2017 Nov 17;9(11):1261. doi: 10.3390/nu9111261.

Abstract. The red seaweed, Kappaphycus alvarezii, was evaluated for its potential to prevent signs of metabolic syndrome through use as a whole food supplement. Major biochemical components of dried Kappaphycus are carrageenan (soluble fiber ~34.6%) and salt (predominantly potassium (K) 20%) with a low overall energy content for whole seaweed. Eight to nine week old male Wistar rats were randomly divided into three groups and fed for 8 weeks on a corn starch diet, a high-carbohydrate, high-fat (H) diet, alone or supplemented with a 5% (w/w) dried and milled Kappaphycus blended into the base diet. H-fed rats showed symptoms of metabolic syndrome including increased body weight, total fat mass, systolic blood pressure, left ventricular collagen deposition, plasma triglycerides, and plasma non-esterified fatty acids along with fatty liver. Relative to these obese rats, Kappaphycus-treated rats showed normalized body weight and adiposity, lower systolic blood pressure, improved heart and liver structure, and lower plasma lipids, even in presence of H diet. Kappaphycus modulated the balance between Firmicutes and Bacteroidetes in the gut, which could serve as the potential mechanism for improved metabolic variables; this was accompanied by no damage to the gut structure. Thus, whole Kappaphycus improved cardiovascular, liver, and metabolic parameters in obese rats.

(3) Chang VS, Okechukwu PN, Teo SS. The properties of red seaweed (Kappaphycus alvarezii) and its effect on mammary carcinogenesis. Biomed Pharmacother. 2017 Mar;87:296-301. doi: 10.1016/j.biopha.2016.12.092. 

(4) Ferraces-Casais, P., Lage-Yusty, M.A., Rodríguez-Bernaldo de Quirós, A. et al. Evaluation of Bioactive Compounds in Fresh Edible Seaweeds. Food Anal. Methods 5, 828–834 (2012). https://doi.org/10.1007/s12161-011-9321-2

(5) Sato Y, Morimoto K, Hirayama M, Hori K. High mannose-specific lectin (KAA-2) from the red alga Kappaphycus alvarezii potently inhibits influenza virus infection in a strain-independent manner. Biochem Biophys Res Commun. 2011 Feb 11;405(2):291-6. doi: 10.1016/j.bbrc.2011.01.031.

(6) Yulianti E, Sunarti, Wahyuningsih MSH. The effect of Kappaphycus alvarezii active fraction on oxidative stress and inflammation in streptozotocin and nicotinamide-induced diabetic rats. BMC Complement Med Ther. 2022 Jan 13;22(1):15. doi: 10.1186/s12906-021-03496-8. 

(7) de Melo MO, Maia Campos PMBG. Application of biophysical and skin imaging techniques to evaluate the film-forming effect of cosmetic formulations. Int J Cosmet Sci. 2019 Dec;41(6):579-584. doi: 10.1111/ics.12577.