Related Experiment Video
Updated: Jul 18, 2026
08:13
Preparation of Biopolymer Aerogels Using Green Solvents
Published on: July 4, 2016
17.8K
Eco-Friendly Extraction, Structure, and Gel Properties of ι-Carrageenan Extracted Using Ca(OH)2
Feng Jiang1,2,3, Yao Liu1,2,3, Qiong Xiao1,2,3,4
1College of Food and Biological Engineering, Jimei University, Xiamen 361021, China.
Marine Drugs
|July 25, 2022
Summary
A new, eco-friendly method for extracting ι-carrageenan from seaweed using calcium hydroxide (Ca(OH)2) offers significant advantages over traditional sodium hydroxide (NaOH) methods, including higher yield and improved gel strength.
Area of Science:
- Marine Biotechnology
- Food Science
- Chemical Engineering
Background:
- Carrageenan is a valuable polysaccharide extracted from red seaweed.
- Traditional extraction methods often use harsh chemicals like sodium hydroxide (NaOH).
- There is a need for more sustainable and efficient carrageenan extraction processes.
Purpose of the Study:
- To develop and evaluate an eco-friendly method for ι-carrageenan extraction.
- To compare the yield, gel properties, and structural characteristics of carrageenan extracted using calcium hydroxide (Ca(OH)2) versus NaOH.
- To assess the quality and functionality of the Ca(OH)2-extracted carrageenan (Ca-IC).
Main Methods:
- Extraction of ι-carrageenan from *Eucheuma denticulatum* using boiling with low-concentration Ca(OH)2.
- Comparison with traditional NaOH extraction method.
- Characterization of carrageenan using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), textural analysis, and rheological measurements.
Main Results:
- The Ca(OH)2 method used significantly less alkali (93.3%) and water (86.8%) compared to NaOH.
- Extraction time was reduced by 25.0%, with a 17.6% higher yield and 43.3% greater gel strength.
- Ca-IC exhibited comparable thermal stability and structural integrity to NaOH-extracted carrageenan (Na-IC), but with enhanced hardness and chewiness.
- Both Ca-IC and Na-IC displayed non-Newtonian, shear-thinning fluid properties, with Ca-IC having lower viscosity.
Conclusions:
- The novel Ca(OH)2 extraction method is more environmentally friendly and efficient than the conventional NaOH method.
- Ca-IC demonstrates superior gel properties, including higher gel strength, hardness, and chewiness.
- This Ca(OH)2-based extraction offers a promising alternative for producing high-quality ι-carrageenan.
Related Concept Videos
00:56Extraction: Advanced Methods
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is formed in...
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...