Non-conventional approaches to food processing in CELSS. I--Algal proteins; characterization and process optimization

Area of Science:

• Biotechnology
• Food Science
• Algal Research

Background:

• Green algae (Scenedesmus obliquus) are a potential sustainable protein source.
• Characterization of algal protein isolates is crucial for nutritional applications.
• Efficient extraction methods are needed to obtain high-quality protein.

Purpose of the Study:

• To characterize protein isolate from Scenedesmus obliquus.
• To evaluate the effectiveness of supercritical carbon dioxide extraction for lipid and pigment removal.
• To assess the nutritional quality and solubility of the resulting protein isolate.

Main Methods:

• SDS-polyacrylamide gel electrophoresis for molecular weight determination.
• Isoelectric focusing for isoelectric point analysis.
• Supercritical carbon dioxide extraction with and without ethanol as co-solvent.

Main Results:

• Algal protein isolate exhibited a wide molecular weight range (15,000–220,000 Da) and isoelectric points (3.95–6.20).
• Amino acid profile favorably compared to FAO standards, with high essential amino acid content.
• Supercritical CO2 extraction with ethanol significantly improved lipid and pigment removal, yielding a protein isolate with enhanced water solubility and good recovery.

Conclusions:

• Scenedesmus obliquus protein isolate is a high-quality protein source, particularly for Controlled Ecological Life Support Systems (CELSS) diets.
• Supercritical carbon dioxide extraction, especially with ethanol, is an effective method for producing a purified, soluble algal protein isolate.
• Further research into algal protein applications in food and nutrition is warranted.