Electrochemical and Spectrophotometric Methods for Polyphenols and 1 Ascorbic Acid Determination in Vegetable Extracts

FIORELLA TULLI; MARIA LAURA LEMOS; DIEGO R. GUTIERREZ; SILVIA DEL C. RODRÍGUEZ; BEATRIZ A. LÓPEZ DE MISHIMA; VERONICA I. PAZ ZANINI

FOOD TECHNOLOGY AND BIOTECHNOLOGY

FACULTY FOOD TECHNOLOGY BIOTECHNOLOGY

Lugar: Zagreb; Año: 2020

1330-9862

Research Background. Fresh-cut fruits and vegetables are considered sources of antioxidant compounds. However, its shelf life is limited due to nutritional, quality, and safety deterioration. Therefore, in recent decades, various methods have been reported for food processing and preservation, as well as for the determination of antioxidant compounds, due to their many benefits when are consumed. The aim of the present work was to compare the performance of electrochemical and spectrophotometric methods so as to analyze the content of polyphenolic compounds and ascorbic acid in vegetable extracts from fruits (eggplant), edible roots (carrot) and leaves (rocket, lettuce, and chard), and evaluate their capability to detect small changes in both antioxidant content in extracts of eggplants previously irradiated with different UV-C light intensity. Experimental Approach. Polyphenolic compounds and ascorbic acid determination was performed by electrochemical and spectrophotometric methods. An enzymatic biosensor and a nanocomposite sensor were used for polyphenolic compounds and ascorbic acid, respectively, in electrochemical measurements; on the other hand, Folin-Ciocalteu and Kampfenkel were used as spectrophotometric techniques. Results and conclusion. Results obtained through the different methodologies were compared and were consistent with each other. Moreover, both methods not only allowed the detection of ascorbic acid and polyphenolic compounds in vegetable extracts but also its variation after UV-C treatment and subsequent storage. Results were according to the treatment and the type of vegetable analyzed. Novelty and Scientific Contribution. Both methodologies were suitable for the quantification of analytes, however, the electrochemical sensors provided greater specificity and selectivity, applicable to different vegetable matrices, obtaining results with higher precision, in a shorter time and with a smaller sample volume, minimizing the economic costs because of the lower consumption of reagents.