The assessment of rosehip (Rosa Canina L.) pseudo-fruit antioxidant capacity: Electrochemical vs. spectrophotometric methods pre and post in vitro gastrointestinal digestion

Extracts of Rosa canina L. have been traditionally utilized in nutrition due to their high concentration of vitamin C and other bioactive compounds, including polyphenols. The total antioxidant capacity (TAC) of these bioactive components serves as a critical parameter for evaluating the biological value of the extract. Conventional spectrophotometric methods have been widely employed for TAC quantification. However, electrochemical techniques present distinct advantages, including rapid analysis, lower costs, and minimal sample preparation. This study aims to compare electrochemical and spectrophotometric methods for TAC determination in Rosa canina L. pseudo-fruit extract before and after in vitro gastrointestinal digestion. TAC was assessed in dried pseudo-fruit extract, the liquid phase post-digestion, and the solid phase post-digestion using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and the ABTS and Folin-Chiocalte spectrophotometric assay. The results indicate that the TAC of the undigested pseudo-fruit extract was significantly higher than that of the digested samples, with the liquid phase exhibiting greater TAC than the solid phase. The electrochemical methods (CV and DPV) produced highly consistent results, whereas the ABTS and Folin-Chiocalte assay yielded slightly lower TAC values post-digestion. The electrochemical approaches demonstrated a substantial reduction in analysis time, as TAC measurements were obtained within seconds without the need for extensive sample preparation, unlike spectrophotometric methods. These results underscore the potential of electrochemical techniques, especially differential pulse voltammetry, as reliable, rapid alternatives to traditional spectrophotometric assays for routine TAC determination in plant extracts. Moreover, electrochemical methods may overcome the limitations of spectrophotometric analysis, such as lower sensitivity and prolonged analytical procedures, thereby enhancing the efficiency and applicability of antioxidant capacity assessments in nutritional and pharmaceutical research.