A Comprehensive Study on the Physicochemical Characterisation of Plant-Based By-Products

Area of Science:

• Materials Science
• Environmental Science
• Biotechnology

Background:

• Global population growth drives unsustainable resource use and waste generation.
• Valorising industrial by-products is key to resource efficiency and waste reduction.
• Plant-based residues offer potential as sustainable materials.

Purpose of the Study:

• To comprehensively characterize the physicochemical properties of four plant-based by-products: rice husk (RH), oregano stalks (OS), eucalyptus leaves (EL), and almond shells (AS).
• To assess the potential of these residues for industrial applications and a circular economy.

Main Methods:

• Physicochemical characterization of RH, OS, EL, and AS.
• Analysis of cellulose, lignin, oil, and metal content.
• Evaluation of hydrophobic properties and wettability.
• Morphological analysis using microscopy.
• Assessment of antioxidant properties over 12 months post-grinding.

Main Results:

• All residues showed similar cellulose and lignin content, with RH and OS higher in cellulose, and EL and AS higher in oils.
• Calcium and potassium were the predominant metals. EL and RH exhibited significant hydrophobicity.
• Morphological analysis revealed diverse particle characteristics: fibrous (OS, RH), fibrous/amorphous (EL), and irregular (AS).
• Antioxidant properties remained stable for 12 months after grinding.

Conclusions:

• The characterized plant-based by-products possess distinct physicochemical properties suitable for various industrial applications.
• These residues can be valorised in sectors like construction, transport, and textiles.
• Utilizing these by-products promotes a circular economy and environmental sustainability.