Enhancing anthocyanin anchorage into treated cellulose nanofibers

• Grant number: 24/22568-3
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: June 26, 2025
• End date: June 25, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Luiz Henrique Capparelli Mattoso
• Grantee: Bruno Ribeiro Luchesi
• Supervisor: Leonardo Coelho Simon
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil
• Institution abroad: University of Waterloo, Canada
• Associated to the scholarship: 23/09856-7 - Colorimetric sensors fo aflatoxins detection, BP.PD

Abstract

Sensors could be considered as devices that transform input stimuli into measurable and easily understandable signals. Colorimetric sensors do that by incorporating compounds that change their colors when stimulated by external factors, such as pH alterations. Anthocyanins are water-soluble polyphenols classically associated with pH-induced changes in colors. This kind of sensor could be made by incorporating these anthocyanins into water-insoluble cellulose films. Despite the hydrogen bonding between them, they are weakly linked by hydrogen bonding, and, in the presence of water, the soluble character of the anthocyanins promotes their release from cellulosic films, disabling the colorimetric sensor. Therefore, promoting modification in the cellulose fibers could enhance the anchorage of anthocyanins and avoid their release. This could be done by mechanically turning cellulose fibers into nano-scaled fibers and by chemically modifying them by controlled mild oxidation. Therefore, the objective of the present proposal, in the context of the post-doctorate project n° 2023/09856-7, is to obtain and modify cellulose nanofibers from eucalyptus and industrial hemp and produce nano-fibrillated cellulose films incorporated with anthocyanins extracted from purple corn and banana bracts. The films will be characterized according to their structural, mechanical and water barrier properties, along with their anthocyanin retention capacity.