Development of green methodologies in the chemical investigation of agro-industrial wastes of sugar cane

Author(s)

Julia Assirati

• Document type: Master's Dissertation
• Press: Botucatu. 2020-09-18.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2020-08-14
• Advisor: Cristiano Soleo de Funari

Abstract

The United Nations preconizes research focused on converting agricultural by-products into useful resources for society because these by-products can contribute to climate change, water and soil contamination, and local air pollution. Green chemistry principles should drive the search for valuable compounds in by-products since every product development begins at the analytical scale. In this work, nine different extraction approaches were investigated side-by-side for sugarcane bagasse, including three reference methods. Two-Liquid-Phase Ultrasound-Assisted Extraction with Probe or Two-Liquid- Phase Dynamic Maceration with a proper vial geometry and with the greener, analysis-compatible, highly available ethanol and n-heptane as alternatives for the reference methanol and n-hexane were the two best approaches based on the extraction and environmental performances. They were applied to the three main solid by-products of the sucroenergetic industrial. The produced hydroethanolic and n-heptane extracts were analyzed by ultra-high-performance liquid chromatography and gas chromatography both coupled to mass spectrometry, respectively, without requiring time, energy, and solvent consuming sample preparation steps like solvent evaporations, metabolite concentration, re-suspensions, and derivatization. Up to 111 compounds were annotated in a single by-product, covering from the very polar sucrose to nonpolar n-hexatriacontanal in a single extraction procedure. Orientin, apigenin-6-C-glucosylrhamnoside, 1-octasonol, octacosanal, and other bioactive compounds were identified in these abundantly available by-products, which are currently just burned to produce energy. These two methods appear as a green, simplified, and highly efficient procedures to comprehensively extract and identify solid sucroenergetic byproducts. These can be applied on metabolite profiling other by-products or complex solid matrices. (AU)

• FAPESP's process: 18/09886-5 - Development of green methodologies in the chemical investigation of agro-industrial wastes of sugar cane
• Grantee: Júlia Assirati
• Support Opportunities: Scholarships in Brazil - Master