New Insights into Cranberry Bioactivity: Polyphenol Composition, Adhesive Effects Against Food Spoilage Yeasts, and Influence on Intestinal Cells

The purpose of this study was to characterise the effect of cranberry (<i>Vaccinium macrocarpon</i>) juice on unicellular and multicellular systems, specifically food spoilage yeasts (<i>Wickerhamomyces anomalus</i>, <i>Dekkera bruxellensis</i> and <i>Rhodotorula mucilaginosa</i>) and intestinal cells (IEC-6 and Caco-2 cells). The effects of both raw cranberry juice and juice digested in vitro were investigated. The juices were analysed for polyphenol content using high-performance liquid chromatography coupled with mass spectrometry. The cranberry juice was evaluated for its impact on yeast surface hydrophobicity and anti-adhesive action using the MATH test and luminometry/microscopy, respectively. We also assessed the effects of raw and digested cranberry juices on IEC-6 and Caco-2 cells by measuring cell viability, metabolic modulation, genotoxicity, and antioxidant activity. Chromatographic analysis of the raw cranberry juice revealed the presence of diverse bioactive compounds, identified as hydroxybenzoic and hydroxycinnamic acids, flavonols, and anthocyanins. After digestion, the cranberry juice remained a rich source of phenolic acids. The yeast strain <i>R. mucilaginosa</i> was characterised by the highest hydrophobicity and adhesive abilities, but cell adhesion in the presence of raw cranberry juice was several times lower for all the tested strains. Both tested cranberry juices reduced ROS levels and were well tolerated by intestinal epithelial cells, without significant cytotoxic or genotoxic effects. Our findings provide new insights into the safety of using cranberry juice across unicellular and multicellular systems. However, further validation in real-world settings is necessary before practical applications.