Gaspar, Fréderic BustosCrespo, TeresaLeonardo, Inês Raquel Carvalho2026-05-062026-05-062026-04-012025-12-29http://hdl.handle.net/10362/202894"Microbial spoilage is a major driver of food loss and waste, with significant economic and environmental impacts worldwide. The fruit juice industry is especially susceptible to spoilage due to the high sugar content and water activity of its products, which create an ideal environment for microbial growth. Although conventional preservation measures, namely acidification and pasteurisation, successfully inactivate most spoilage organisms, they are ineffective against thermoacidophilic, spore-forming bacteria of the genus Alicyclobacillus (ACB). These resilient organisms survive heat treatments and produce distinctive off-flavours that compromise sensory fruit-based products’ quality. While non-pathogenic, ACB contamination undermines consumer trust, drives product recalls, and contributes directly to food waste. Historically, research has focused on Alicyclobacillus acidoterrestris and guaiacol production; however, emerging evidence reveals considerable genetic, metabolic and phenotypic diversity across the genus highlighting the urgent need to broaden and update risk assessment frameworks and develop more effective spoilage prevention strategies.(...)"engMicrobial spoilageAlicyclobacillus (ACB)fruit-processingenzymatic pathwaysdoctoral thesis101858124