Screening out key organic acids for inducing diarrhea in fermented blueberry wine based on the spectrum-effect relationship

Abstract Fermented blueberry wine (BW) contains organic acids that may contribute to gastrointestinal discomfort, but the specific compounds responsible for diarrhea remain unclear. This study aimed to identify the key diarrhea-inducing organic acids by establishing a spectrum-effect relationship between chemical composition and biological activity. Ultra-high performance liquid chromatography (UHPLC) analysis revealed eight major organic acids in BW, with quinic acid predominating. Eight anion-exchange resin pretreatments combined with UHPLC-diode array detector successfully characterized the organic acid profiles of BW. Subsequent studies in mice demonstrated that resin treatment significantly alleviated BW-induced diarrhea in mice, reducing the diarrhea index and attenuating intestinal propulsion. Histopathological and biochemical analyses demonstrated restored intestinal integrity, improved gut barrier function, and normalized serum electrolytes, confirming that organic acids are the causative agents. Further spectrum-effect relationship was established through grey relational, orthogonal partial least squares, and Spearman rank correlation analysis, revealing quinic acid as exhibiting the strongest positive correlation with diarrhea incidence. The findings suggest that quinic acid is a primary contributor to diarrheal effects observed in BW. This study provides critical insights into regulating components in BW production to mitigate adverse gastrointestinal effects and a methodological foundation for material basis research in functional foods.