ABSTRACT This study aimed to examine the effect of pH on extraction efficiency, bioactive compounds, and potential food applications of anthocyanin‐rich extracts from C. ternatea flowers. Extractions were carried out under controlled conditions across a pH range of 1 to 13. The results indicated that total anthocyanin content (TAC) peaked at pH 3.0, while total polyphenol content (TPC) and DPPH antioxidant activity peaked at pH 7.0. These two pH conditions were further characterized using UV–Vis spectroscopy, scanning electron microscopy (SEM), and liquid chromatography–high‐resolution mass spectrometry (LC‐HRMS) to evaluate differences in absorbance spectra, cellular structures, and anthocyanin composition. LC‐HRMS analysis revealed a complex profile of anthocyanins and flavonoids, including Quercetin 3‐2G‐rhamnosylrutinoside, Delphinidin‐3‐(cis‐p‐coumaroyl‐glucoside), Kaempferol 3‐(6‐p‐coumaroyl)‐rutinoside, Kaempferol derivative, Cyanidin‐3‐(p‐coumaroyl)glucose, Kaempferol‐rhamnosyl‐malonyl‐glucoside, and Aglycoside cyanidin which were exclusively identified at the flower's natural pH (6.8–7.0). The observed compositional differences are associated with pH‐dependent structural transitions of anthocyanins from flavylium cations under acidic conditions to quinoidal base forms at near‐neutral pH. These findings provide insight into pH‐dependent anthocyanin behavior and offer guidance for optimizing extraction conditions for specific food applications. Anthocyanin and polyphenol extracts at pH 7 were tested for lipid oxidation in gummy candies. The results demonstrate the potential application of butterfly pea anthocyanins as functional ingredients in food systems, particularly as natural colorants with antioxidant functionality. Overall, this study provides a mechanistic understanding of pH‐dependent anthocyanin behavior and supports the use of neutral‐pH C. ternatea extract as a stable and multifunctional ingredient in lipid‐containing foods.
Nguyen et al. (Mon,) studied this question.