Natural Deep Eutectic Solvent-assisted extraction to obtain reedy to use phenolic compounds extracts from orange peel waste (Citrus sinensis)

• Grant number: 25/06661-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Stanislau Bogusz Junior
• Grantee: Lucas Duarte Rocha
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/03229-8 - Synthesis, characterization and applications of natural deep eutectic solvents (NADES), AP.PNGP.PI

Abstract

The market for phenolic-rich extracts has grown rapidly, driven by the food industry's demand for natural ingredients with antimicrobial and antioxidant properties that allow for synthetic additive-free labeling. The São Carlos region in São Paulo state is known for its tradition in citrus production, primarily oranges (Citrus sinensis), mostly destined for frozen concentrated juice production for export. The production of orange juice generates large amounts of peel waste, which is rich in phenolic compounds. These phenolic compounds exhibit biological antioxidant and antimicrobial activity and are essential for plant growth and defense. In this research project, we propose to use green and environmentally friendly solvents - specifically natural deep eutectic solvents (NADES) - to obtain ready-to-use phenolic-rich extracts from citrus industry waste. For this purpose, we will synthesize NADES based on: choline chloride and sorbitol and choline chloride and lactic acid. The NADES will be properly characterized for: density, pH and polarity (solvatochromism). We will then employ ultrasound-assisted solid-liquid extraction of orange peels using these solvents. A 60% ethanol-water solution will be used as control. The obtained extracts will be recovered and evaluated for total phenolic content, antioxidant activity and HPLC analysis. Through this work, we expect to provide relevant and innovative insights regarding the replacement of organic solvents in obtaining bioactive-rich orange peel extracts with potential applications in the food and pharmaceutical industries, promoting the sustainable use of natural extracts as an alternative to synthetic additives.