CHARACTERIZATION OF BIOACTIVE COMPOUNDS PROFILE OF PINEAPPLE CROWN (ANANAS COMOSUS) DETERMINED BY GC-MS AND UPLC-MS-MS

The pineapple (Ananas comosus) is one of the most produced fruits in Brazil. In 2016, about 1.8 million tons were produced and as a consequence, high amount of residues are generated from its processing. However, those unconventional parts also represent a rich source of bioactive compounds and present technological and economic interest. The objective of this study was to obtain and characterize the bioactive profile of pineapple crown flour (PCF). The pineapple crowns were collected in hortifrutis unit during three days successively. The samples were washed, fractionated, dried in a ventilated oven (65°C/10h and 90°C/1h), ground and stored. The chemical composition was performed according to AOAC and total starch (TS) and resistant (RS) by enzymatic method. For antimicrobial activity, the agar diffusion technique was used with the bacteria Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella sp. using Mueller-Hinton agar. Essential Oil (EO) was extracted by hydrodistillation during 4 hours and recovery from Clevenger apparatus with the aid of ethyl acetate and analyzed by gas chromatography (GC) combined with a flame ionization detector (FID) or mass spectrometry (MS). Free phenolic compounds (PC) were extracted separately with ethanolic and methanolic solutions and bound PC (pellet) by extraction alkaline and acid hydrolysis. The PC were analyzed by UPLC-MS-MS (Xevo-G2S ESI-QTOF, Waters). Data were processed using a customized database in the Progenesis QI, considering the exact mass error (10 ppm), isotope similarity (80%) and reproducibility (3/3). The PCF presented a yield of 15.32% ± 1.24 and low water activity (0.44 ± 0.02). The centesimal composition (g/100g) revealed moisture of 9.2 ± 0.58, 5.31 ± 0.06 of ashes, 6.91 ± 0.61 of proteins, 1.68 ± 0.09 of lipids and 76.85 ± 0.43 of total carbohydrates. The content of TS and SR were, respectively, 1.06 ± 0.13 and 0.12 ± 0.01. The formation of a 6 mm inhibition halo for Staphylococcus aureus was observed. The EO obtained average yield of 0.07%. The preliminary analysis showed the EO was rich in free fatty acids (%): dodecanoic acid (0,71 ± 0,81), pentanoic acid (1.64 ± 1.21), hexadecanoic acid (37.80 ± 6.45), linoleic acid (30.62 ± 4.17) and oleic acid (12.13 ± 7.54). Additionaly, phytol (1.65 ± 1.27) must be included in the group of the major components of the PCF essential oil. This diterpene is a well-known antioxidant compound. Globally, 157 PCs were identified, where most were in bound form (128) than in free form (67), with 19 common compounds such as p-coumaric acid, sinapinic acid, caffeic acid and ferulic acid . There was no difference in the number of identifications between the ethanolic and methanolic extracts for the free phenolics, varying only the total abundance of ions. For the bound compounds, the methanolic extracts presented more number of particular compounds (7) than the ethanolic extracts (3). Daidzin, clroic acid, 3,7-dimethoxyquietin and 3-O-glycoside isorannetin were the most abundant free phenolic compounds, while p-coumaric acid, 4-vinylphenol, ferulic acid and 4-hydroxybenzaldehyde were the most abundant phenolics. The PCF proved to be a rich PC source and antioxidants.