Emprego de espectrometria de massas com ionização paper spray para determinação do perfil químico da farinha de casca e de polpa da banana verde Cavendish (musa AAA) e avaliação do seu potencial funcional

Abstract

The banana (Musa sp.) is one of the most cultivated fruits in the world and have an important economic and social role. As an cheap source of phenolic compounds, this fruit has attracted a great deal of attention, but few studies have been carried out with green banana, and the use of flour obtained from the peel and green banana pulp could help in the ingestion of these compounds. The changes in phenolic composition are very complex, as they vary according to the food, cultivars and different heat treatments and processing. In this context, the objective of this work was to evaluate the functional potential of peel flour and green banana pulp (Musa AAA) Cavendish cv. 'Nanicão' using the equipment: Air Fryer (180ºC), oven drier with air circulation (70ºC) and natural gas oven (180ºC). The obtained flours were characterized in terms of coloration, yield, water activity, moisture, profile of phenolic compounds by liquid chromatography (UPLC-UV / Vis), chemical profile by paper spray ionization mass spectrometry (PS-MS) and antioxidant activity. The flours were thin and homogeneous in light yellow (pulp) and brown (peel), with a moisture content in accordance with legislation and water activity with values lower than 0.60. The content of phenolic compounds was obtained by the method of Folin Ciocalteau, with a higher content in the peel flour in relation to the pulp and higher in the flours obtained in the Air Fryer equipment followed by the oven drier with air circulation and natural gas oven, which corroborates with the values obtained for antioxidant activity by DPPH method. Higher antioxidant activity was also observed in the peel flour obtained in the Air Fryer equipment by the ABTS method and in the peels flours in relation to the pulps for the FRAP technique. By the UPLC-Uv/Vis method, were found in banana peel flour: chlorogenic acid, caffeic acid, ellagic acid, rutin and catechin, with gallic acid being the major compound. Gallic acid and catechin were the most important contributors to antioxidant activity in green banana flour obtained in the Air Fryer, and gallic acid for flours obtained in the oven drier with air circulation and natural gas oven. In the characterization by PS-MS, the presence of phenolic acids, flavonoids, β-sitosterol and the compounds suggested as umbelliferone and morroniside, all observed on the Air Fryer. These results suggest that Cavendish green banana flour, in particular peels, can be considered a food with functional potential and Air Fryer equipment an alternative method of drying.