Cold plasma at various voltage, gas flow rate, and time assisted extraction of blue pea flower: Quantitative UPLC-ESI/MS/MS analysis of bioactive compounds, phenolics, and anthocyanin content

Butterfly pea (Clitoria ternatea) is a rich source of anthocyanins and has gained popularity as an herbal tea. However, conventional thermal processing could degrade its thermolabile bioactive components, necessitating alternative non-thermal processing to promote its commercial applications in the food industry. This study aims to assess the effects of sample preparation (powder vs. aqueous solution) and cold plasma treatment conditions (applied voltages, treatment times, and gas flow rates) on the extractability and stability of bioactive compounds in butterfly pea flowers. Quantitative analysis using liquid chromatography-tandem mass spectrometry was performed to assess the yield, bioactive compounds, and chemical composition of the extracts. Besides, response surface methodology and principal component analysis (PCA) were employed to elucidate the impact of experimental variables on extract characteristics. Results indicated significant concentrations of delphinidin, cyanidin, and their derivatives in all extracts. Aqueous samples treated at higher voltages and for longer durations exhibited increased total anthocyanin (+92 % for 5 min at 180 V) and phenolic content (+32 % for 3 min at 100 V). PCA revealed strong correlations between independent variables and extracts' biochemical properties, highlighting the importance of optimizing treatment parameters. Furthermore, anthocyanins with increased side chains were observed to be more resistant to degradation under plasma carrier gas flow rate and plasma processing. Powder samples experienced more significant degradation when treated with plasma due to increased free radical generation. These findings elucidated the interaction between plasma and the plant matrix, demonstrating the potential of cold plasma technology for enhancing extraction in an eco-friendly manner and promoting more sustainable food production.