A Rapid Method for Determination of Some Phenolic Acids in Brazilian Tropical Fruits of Mangaba(Hancornia speciosa Gomes)and Umbu(Spondias tuberosa Arruda Camara)by UPLC

A rapid chromatographic method for the determination of six phenolic acids (chlorogenic, ferulic, gallic, p-coumaric, protocatechuic and vanillic acids) by ultra performance liquid chromatography (UPLC), was developed and applied for Brazilian tropical fruits mangaba (Hancornia speciosa Gomes) and umbu (Spondias tuberosa Arruda Camara). A multivariate statistical experimental design was employed to optimize analytical conditions (solvent A, solvent B concentrations and flow rates). Samples were cleaned-up by solid-phase extraction (SPE) with different solvents (methanol and acetone) employing SPE cartridges (amine and octadecyl-silane). The method using dihydrogen potassium phosphate 5 mmoL as solvent A and 8% acetonitrile as solvent B presented limits of detection varying from 14 to 94 ng.mL, limits of quantification from 39 to 277 ng.mL-1 with 2 μL of injection volume while total run time for all six compounds was only 9.6 minutes. Higher recovery was obtained by extraction with methanol-acetone of 69.51% to 72.59% for protocatechuic acid and 69.58% to 126.31% for the chlorogenic acid. The concentrations of chlorogenic, p-coumaric and ferulic acids in mangaba extracts were 113.4, 32.1 and 1.5 μg.g-1, respectively while concentrations of chlorogenic, protocatechuic, gallic, vanillic, ferulic and p-coumaric acids present in umbu fruit were 118.9, 141.3, 3.5, 2.5, 2.2 and 1.8 μg.g-1, respectively.

Method Optimization Study on Isolation of Volatile Compounds by Headspace Solid-Phase Microextraction (HS-SPME) from Custard Apple (<i>Annona squamosa</i>L.) Pulp.

Aroma is an important quality parameter, which can help in delaying degradative processes and hence understanding the volatile compounds that are part of an aroma is extremely important. Thus, the aim of this study was to isolate the volatile compounds present in custard apple (Annona squamosa L.) pulp by solid-phase microextraction (SPME) technique using 3 different fibers (DVB/CAR/PDMS, PDMS and PDMS/DVB). An experimental design was set up to evaluate the best extraction conditions wherein the variables were extraction temperature (minimum 28°C, maximum 62°C), ionic strength (minimum 0, maximum 30.0%) and sample concentration (min 1, max 99.0%). The separation of volatiles was achieved in chromatographic columns of different polarity (polar and non-polar) while identification of volatile compounds was performed by high resolution gas chromatography system coupled with mass spectrometry. The results obtained using 3 different fibers revealed the isolation of 71 compounds with fiber DVB/CAR/PDMS, while only 30 and 21 compounds were isolated using fibers PDMS/DVB and PDMS, respectively. The major classes of compounds identified were terpenes, esters, alcohols and aldehydes. Optimum conditions for obtaining higher number of volatiles for non-polar column were 45°C for extraction temperature, 15% of sodium chloride and 50% of pulp amount which resulted in isolation of a maximum of 78 peaks.