Nutritional properties, determination of phenolic compounds and antioxidant potential of Victoria amazonica (Poepp.) J.C. Sowerby petiole

Abstract

This study reported for the first time the chemical profile of the petiole of Victoria amazonica (Poepp.) J.C. Sowerby, a non-conventional edible plant (NCEP), and demonstrated its nutritional and functional potential. Its proximate composition was determined by verifying the fiber, lipid, protein, ash, and carbohydrate contents in fresh samples. V. amazonica petiole has a high moisture content (97.62%), while has low amounts of protein, crude fiber and carbohydrates (3.10%, 1.81%, and 5.78%, respectively). At 19.5 kcal g− 1, this NCEP can be classified as a low-calorie food, especially due to low lipid content of 1.47%. Amongst the extracts and solvent-partitioned fractions, the ethyl acetate fraction showed the highest total phenolic content (25.47 GAE mg 100 g− 1) and antioxidant potential (IC50: 13.67 µg mL− 1), which were evaluated using the Folin-Ciocalteu and DPPH methods, respectively. In comparison with well-known conventional fruits and plants, based on results obtained for the methanolic extract, the petiole showed a low total phenolic content (13.61 GAE mg 100 g− 1) and also an antioxidant potential (IC50: 50.12 µg mL− 1) that was 10-fold higher than the gallic acid reference standard. Five phenolic acids were identified by dereplication using liquid chromatography coupled to mass spectrometry (LC-DAD-ESI-Q-TOF-MS). Gallic, ferulic, p-coumaric and 3,4-dihydroxybenzoic acids, as well the flavonoid quercetin-3-O-rhamnoside, were identified in methanolic extract. As a low-carb and low-fat food, this unconventional edible plant can be incorporated into diets with dietary restrictions and can be classified as a functional food since it is a source of bioactive compounds.