Volatile compounds from organic and conventional passion fruit (Passiflora edulis F. Flavicarpa) pulp

The volatile compositions from organic and conventional passion fruit pulps produced in Brazil were investigated. The pulps were also physicochemically characterized. The volatile compounds from the headspace of the passion fruit pulp were stripped to a Porapak Q trap for 2 hours; they were eluted with 300 µL of dichloromethane, separated by gas chromatography/flame ionisation detection and identified through gas chromatography/mass spectrometry. Both pulps conformed to the requirements of the Brazilian legislation, indicating they were suitable to be industrialized and consumed. A total of 77 compounds were detected in the headspace of the passion fruit pulps - 60 of which were identified, comprising 91% of the total chromatogram area. The major compounds were the following: ethyl butanoate, 52% and 57% of the total relative area of the chromatogram for the organic and conventional passion fruit pulps, respectively; ethyl hexanoate, 22% and 9%, respectively; and hexyl butanoate, 2% and 5%, respectively. The aroma of the organic passion fruit pulp is mainly related to the following volatile compounds: ethyl hexanoate, methyl hexanoate, β-myrcene and D-limonene. The conventional passion fruit pulp presented methyl butanoate, butyl acetate, hexanal, 1-butanol, butyl butanoate, trans-3-hexenyl acetate, cis-3-hexen-1-ol, butyl hexanoate, hexyl butanoate, 3-hexenyl butanoate and 3-hexenyl hexanoate as the main volatile compounds for aroma.

Study of the volatile compounds from plum (Prunus domestica L. cv. Horvin) and estimation of their contribution to the fruit aroma

Simultaneous Distillation-Extraction (SDE) and headspace-solid phase microextraction (HS-SPME) combined with GC-FID and GC-MS were used to analyze volatile compounds from plum (Prunus domestica L. cv. Horvin) and to estimate the most odor-active compounds by application of the Odor Activity Values (OAV). The analyses led to the identification of 148 components, including 58 esters, 23 terpenoids, 14 aldehydes, 11 alcohols, 10 ketones, 9 alkanes, 7 acids, 4 lactones, 3 phenols, and other 9 compounds of different structures. According to the results of SDE-GC-MS, SPME-GC-MS and OAV, ethyl 2-methylbutanoate, hexyl acetate, (E)-2-nonenal, ethyl butanoate, (E)-2-decenal, ethyl hexanoate, nonanal, decanal, (E)-β-ionone, Γ-dodecalactone, (Z)-3-hexenyl acetate, pentyl acetate, linalool, Γ-decalactone, butyl acetate, limonene, propyl acetate, Δ-decalactone, diethyl sulfide, (E)-2-hexenyl acetate, ethyl heptanoate, (Z)-3-hexenol, (Z)-3-hexenyl hexanoate, eugenol, (E)-2-hexenal, ethyl pentanoate, hexyl 2-methylbutanoate, isopentyl hexanoate, 1-hexanol, Γ-nonalactone, myrcene, octyl acetate, phenylacetaldehyde, 1-butanol, isobutyl acetate, (E)-2-heptenal, octadecanal, and nerol are characteristic odor active compounds in fresh plums since they showed concentrations far above their odor thresholds.

Antioxidant activities of fractions from longan pericarps

The antioxidant activities of ethanolic crude extract (LPCE) and its four different solvent sub-fractions (namely, diethyl ether fraction (LPDF), ethyl acetate fraction (LPEF), n-butyl alcohol fraction (LPBF) and residue fraction (LPR)) from longan pericarps were investigated employing various systems including 2,2-diphenyl-1-picrylhydrazyl (DPPH)/ 2,2'-amino-di(2-ethyl-benzothiazoline sulphonic acid-6)ammonium salt (ABTS)/hydroxyl radical scavenging activity, total phenolic content and reducing power. Each extract showed concentration-dependent antioxidant activity. LPEF showed the highest scavenging activity against DPPH, ABTS and hydroxyl radicals with EC50 values of 0.506, 0.228 and 4.489 mg/mL, respectively. LPEF showed the highest reducing power with EC50 values of 0.253 mg/mL. The next was LPDF with EC50 values of 0.260 mg/mL. LPEF possessed the highest total phenolic content (230.816 mg/g, expressed as gallic acid equivalents), followed by LPDF, LPBF, LPCE and LPR. The results suggested that longan pericarp fractions possessed significant antioxidant activities and could be a promising source of natural antioxidant.