Improvement of Phenolic Compound and Anthocyanin Extraction Efficiency From Clitoria ternatea by Autogenous Pressurization Method in a Sealed-Vessel and Determination of Anthocyanin Compounds by LC-HRMS.

Clitoria ternatea L. (butterfly pea) is an edible tropical flower widely used as a natural colorant and a source of anthocyanins and phenolic compounds in food applications. This study aimed to optimize the extraction of anthocyanins (TAC) and improve total phenolic content (TPC), antioxidant capacity (DPPH) from Clitoria ternatea flowers using the autogenous pressurization method in a sealed vessel, also known as closed-vessel extraction under autogenous pressure (CVE-AP). Single-factor experiments were first performed to investigate the effects of temperature, ethanol concentration, extraction time, and liquid-to-solid ratio. Based on these results, the three most influential factors: autogenous pressure, time, and liquid-to-solid ratio were modeled using response surface methodology (RSM) with a central composite design (CCD). The optimal extraction conditions were identified as 28.2 psi, 36 min and a liquid-to-solid ratio of 18:1. Under these conditions, the experimental values achieved were TAC 2.72 ± 0.18 mg/g dry matter, TPC 56.82 ± 2.16 mg GAE/g dry matter, and antioxidant capacity (DPPH) 175.78 ± 6.63 μmol TE/g dry matter. These results demonstrate that CVE-AP enhanced anthocyanin recovery by 86% compared with atmospheric pressure extraction. UPLC-UV profiling showed a flavonol-rich extract dominated by rutin: 33.38 mg/g, achieving for ~67.7% of quantified phenolics. LC-HRMS identified seven pigment-related flavonoids, comprising anthocyanin and flavonol derivatives, including: Delphinidin-3-O-(cis-p-coumaroyl-glucoside), Kaempferol 3-O-(6'-O-p-coumaroyl)-rutinoside, Cyanidin-3-O-(p-coumaroyl) glucose, Delphinin glucoside. CVE-AP delivered significantly higher anthocyanin yields than atmospheric extraction, supporting a green and efficient route to valorize butterfly-pea bioactives for functional food and nutraceutical applications.