Microbiological mapping of the production of fruit-based beverages

Sammanfattning

Fruit-based beverages, such as juices and ciders, are widely consumed due to their nutritional value, but are also susceptible to microbial spoilage, contributing to food waste. This study aimed to investigate the presence and behaviour of spoilage microorganisms along the production lines of two fruit-based beverages: apple cider and a pear fruit drink. Sampling was conducted at various processing stages, and environmental contamination was assessed through equipment swabs and air testing. Microorganisms were identified using MALDI-TOF mass spectrometry. Yeasts, particularly Zygosaccharomyces rouxii, were dominant in raw materials, although high Brix levels seemed to inhibit their growth. Microbial populations in apple concentrate varied by storage conditions, with Z. rouxii more prevalent in wine-cellar-stored tanks and Aureobasidium pullulans in outdoor tanks. Filtration proved to be the most effective microbial control step, while carbonation and preservative addition showed unexpected limited impact. Equipment swabs revealed widespread microbial presence, highlighting hygiene shortcomings. The microbial flora of the blending area appeared as more diverse than the wine cellar. Airborne mould diversity was high, though the organisms were unable to be identified with the method used. MALDI-TOF MS is a powerful tool for the typing of microorganisms but changes in the method used are necessary to optimize its possibilities. This study created a microbial map of contamination sources, offering insights into spoilage risks and potential improvements for microbial control strategies in beverage production, ultimately supporting food safety and waste reduction.