Development of a pH Sensor from Jabuticaba Peels and Compostable Polymers via 3D Printing for Use in Food Packaging

• Grant number: 25/12720-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Roniérik Pioli Vieira
• Grantee: Guilherme Gregório Pagotto
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

pH indicators have gained prominence in "smart" food packaging due to their ability to monitor the freshness of packaged food before visible signs of spoilage appear. Among the most commonly used substances as indicators are anthocyanins, which are found in red, purple, and blue fruits, plants, and flowers. In general, these compounds can be incorporated as additives in polymer films. Their use in additive manufacturing is still limited, revealing a potential area of research given the possibility of producing materials tailored to consumer needs. Additionally, the customization of 3D-printed sensors can significantly expand the applicability of these materials to meet specific requirements while using less plastic. Thus, the goal of this project is to develop a 3D-printed pH sensor that is flexible and mechanically resistant, leveraging the properties of a blend of polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (PBAT), and distinguishing itself from traditional approaches that typically use (bio)polymeric films prepared via wet processing. The incorporation of anthocyanins obtained from repurposed jabuticaba peels will allow for a visual indication of pH through colorimetric changes, while also reusing an agricultural by-product for applications in smart food packaging.