Integrated Phytochemical, Anthocyanin, Organic Acid and Colour Profiling of Plant-Derived Syrups as Potential Natural Food Ingredients

Plant-derived syrups are traditional sugar-rich products that may serve as potential natural food ingredients, but their quality-related characteristics depend on raw material composition, acidity, phenolic constituents, pigments and colour attributes. This study characterised 15 plant-derived syrup products prepared from botanical and fungal raw materials collected in Latvia during the 2025 vegetation season. The syrups were analysed for pH, total soluble solids, titratable acidity, total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC) determined spectrophotometrically, smartphone-based CIELAB colour parameters and organic acid content by HPLC-DAD. Data were evaluated using correlation analysis, PCA and K-means clustering as exploratory tools. The syrup products differed in acidity, phenolic and flavonoid indices, TAC, colour characteristics and organic acid profiles. Fruit-derived syrups showed the widest variation in titratable acidity, while total soluble solids showed no significant linear association with titratable acidity. TPC correlated strongly with TFC in samples with quantifiable TFC values, whereas TAC was associated more closely with reduced lightness than with increased redness. Organic acid profiles provided additional product-level differentiation. Overall, the integrated analytical approach provides a compositional basis for the further evaluation of plant-derived syrups as potential natural food ingredients.