Non-thermal inactivation of probiotic cultures by pulsed electric fields for bioactive-rich postbiotic production

• Grant number: 25/08047-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: May 01, 2026
• End date: October 31, 2026
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Eric Keven Silva
• Grantee: Iuri Procópio Castro Brito
• Supervisor: Javier Raso
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Universidad de Zaragoza, Spain
• Associated to the scholarship: 24/04051-3 - Pulsed electric field and ultrasound applied in the development of functional beverages: Cultivation of probiotics, delivery in beverages rich in bioactive compounds and microbial control, BP.DD

Abstract

The growing consumer demand for functional and sustainable foods has driven the search for innovative ingredients and processing methods. Postbiotics, derived from inactivated probiotic cultures, offer health benefits associated with their intracellular bioactive compounds and present advantages over probiotics in terms of stability and safety. However, conventional thermal inactivation methods can degrade these sensitive compounds. This study aims to investigate pulsed electric fields (PEF) as a non-thermal technology for the inactivation of probiotic cultures, focusing on achieving complete microbial inactivation while preserving the functional integrity of intracellular metabolites. Lactobacillus acidophilus, Propionibacterium freudenreichii, and Saccharomyces boulardii cultures will be activated and resuspended in saline solution. Different electric field strengths will be tested to evaluate their effect on microbial inactivation and postbiotic production. Additional inactivation methods - thermal treatment, high-intensity ultrasound, and pH shifting - will also be applied for comparative purposes. Cell viability, physiological functions assessed by flow cytometry, microstructure, and antioxidant activity will be analyzed to characterize the treatments. Beyond inactivation efficiency, the preservation of bioactive compounds will be evaluated to determine the most effective method. The findings will support the development of postbiotic ingredients using non-thermal technology for application in health-promoting functional foods.