Applications of Agar in
Summary
Agar is widely used in the food industry, pharmaceutical industry, bioengineering and other fields. It has coagulation and stability and is often used as a thickener, coagulant, suspending agent, emulsifier, stabilizer and preservative.- Author Name: Tylor Keller
Agar is a natural polysaccharide extracted from red algae, primarily species of the genera Gelidium and Gracilaria. Agar is composed of two primary components: agarose and agaropectin. It is widely used in the food industry, pharmaceutical industry, bioengineering and other fields. It has coagulation and stability and is often used as a thickener, coagulant, suspending agent, emulsifier, stabilizer and preservative.
Applications of Agar
- Microbiology
- Culture Media: Agar is a common culture media that is used to grow microbes. The gelling nature of the material creates a hard surface for bacterial and fungal colonies to grow on.
- Electrophoresis: Agarose gels are used in electrophoresis techniques (gel electrophoresis and pulsed field gel electrophoresis) to fragment DNA and RNA by size.
- Food Industry
- Thickener and Gelling Agent: Agar is used as a natural thickener and gelling agent in jellies, puddings, desserts etc. It is a favourite for vegans and vegetarians to replace gelatin.
- Clearing Agent: Agar is useful to make wine, fruit juice and so on clear by removing suspended solids.
- Pharmaceutical Industry
- Drug Delivery: Agar-based hydrogels in drug delivery to regulate the release of medication.
- Wound Dressing: Agar dressings are used in the wound healing because they are absorbent and emollient.
- Biotechnology
- Tissue Engineering: Agar is an encapsulant material for tissue engineering which is applied to support the growth and differentiation of cells.
- Immunodiffusion: Antigen and antibody detection using agar gel diffusion.
- Solubility
At room temperature, agar is neither soluble in water nor in inorganic and organic solvents. It is only slightly soluble in ethanolamine and formamide, but it can be dissolved in water and some solvents under heating conditions.
Dried agar can absorb water and swell at room temperature, and the water absorption rate can reach 20 times. It can be dissolved in water to form a solution when heated to 95℃. Agar solution can form gel at room temperature. Compared with other substances that can form gel, it has the strongest gel ability at the same concentration. Even a 0.1% agar solution can solidify at around 30℃.
Agar can also be dissolved in boiling low-concentration ethanol (30% - 50%) solutions. In some high-concentration electrolyte solutions, such as sodium sulfate, magnesium sulfate or ammonium sulfate, it will be salted out and precipitated.
