Comprehensive elucidation of volatile, phenolic, and organic acid profiles in Turkish mallow (Malva sylvestris L.) petal herbal tea: impact of diverse brewing conditions

Abstract

BACKGROUND Mallow (Malva sylvestris L.) petals are traditionally consumed as herbal tea across the Mediterranean for their soothing and anti-inflammatory properties; however, scientific characterization of this consumption-relevant matrix under realistic brewing conditions remains scarce. This study comprehensively elucidates the impact of three household infusion protocols, short hot brewing (4 min at 98 degrees C), extended hot brewing (16 min at 98 degrees C), and cold brewing (24 h at 25 degrees C), on the volatile, phenolic, and organic acid profiles, antioxidant capacity, and sensory attributes of Turkish endemic M. sylvestris petal tea.RESULTS Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS), coupled with univariate (one-way analysis of variance (ANOVA) with Duncan's test, effect size) and multivariate (principal component analysis (PCA), Spearman rank correlation) statistics, distinct phytochemical fingerprints were identified for each method. Cold infusion yielded the highest total phenolic and total flavonoid contents and superior ABTS activity, while short hot infusion best preserved esters and terpenes, correlating strongly with high hedonic scores for 'Aroma' and 'Overall Liking.' Extended hot infusion promoted lipid oxidation products (e.g., nonanal) and partial degradation of thermolabile antioxidants. PCA revealed clear separation of samples by infusion type, and Spearman correlations linked specific volatiles (e.g., ethyl palmitate, nonanoic acid) and phenolics (e.g., gallic acid, protocatechuic acid) to sensory and functional outcomes.CONCLUSION Changes in brewing time and temperature significantly affect the bioactive and sensory quality of teas. Short hot infusion offers superior sensory scores, ideal for daily consumption. Cold brewing method yields higher phenolics but lower sensory appeal, preferable for health. Extended hot infusion compromises both quality and function. These findings guide balance between health benefits and sensory quality.