Table 4.
Biomaterial passport: carrageenans.
| Scientific Name | Carrageenans |
|---|---|
| Chemical structure, MW |
|
| Carrageenans, hydrophilic linear sulphated galactans, being composed of alternate units of d-galactose and 3,6-anhydro-galactose linked by α 1-3 and β 1-4 glycosidic bonds, are divided into groups, i.e., kappa (κ), iota (ι), lambda (λ), mu (μ), nu (υ), theta (θ) and others, which is based on their solubility in potassium chloride [90]. Their MW was reported to be within 200–800 kDa [167]. | |
| Physicochemical properties | Hydrocolloids of different solubility: κ-carrageenan is insoluble in cold water [168]; a higher hydrophilicity was shown for ι-carrageenan, while λ-carrageenan is freely soluble in water under most conditions [168] and even in cold milk [169]. λ-carrageenan is non-gelling and is used rather for its thickening properties and the ability to form creamy texture [169]. κ- and ι-carrageenans form gels [169] following heating [167,170] and cooling in the presence of K+, Ca2+, NH4+ cations [168]. ι-carrageenan is used to obtain soft gels [169] while κ-carrageenan, the main carrageenan applied in industry, forms strong, brittle gels the strength of which can be improved by locust bean gum, corn starch and wheat starch [168]. Thus, due to their specific texture properties carrageenans are widely used in food industry to improve appearance (creaminess, homogeneity), organoleptic qualities (juiciness, mouthfeel), and application (spreadability) [169]. |
| Carrageenan extraction/Physical form after extraction | Carrageenans are extracted from various red algae species [90,171,172,173] by hot alkaline treatment followed by ethanol precipitation [168] in the form of translucent plates or powders [168,174]. |
| Biomaterials properties (biocompatibility, biodegradability, toxicity, immune responses) | Carrageenans were shown to be biocompatible, biodegradable, non-immunogenic, and non-toxic compounds [19,175,176,177]. |
| Market situation (world market reports) |
The global carrageen market is predicted to reach USD 1.25 million by the end of 2024 [178]. |
| Patents | Currently, about several hundreds of patents on the extraction and applications of carrageenans exist. |
| For search, use: https://patents.google.com/ | |
| Selected examples: | |
| US3956173A. Preparation of gels based on carrageenan | |
| US5502179A. Carrageenan product and a method of producing same | |
| US3094517A. Process for treating a polysaccharide of seaweeds of the gigartinaceae and solieriaceae families | |
| US3280102A. Preparation of carrageenan having improved water dispersibility | |
| US3907770A. Process of extracting carrageenan from seaweed | |
| JPS57202302A. Preparation of carrageenan | |
| US4443486A. Modified extractive of Eucheuma cottonii seaweed and composition containing same | |
| US6387354B1. Semi-refined carrageenan dentifrice binder | |
| WO2002048199A3. Production of carrageenan and carrageenan products | |
| SU756683A1. Method of obtaining jellifier from red algae | |
| CN103788225A. Production method of modified carrageenan | |
| AU2003245252A1. Carrageenan based antimicrobial compositions |