Proximate Compositions, Phenolic Compounds, Antioxidant Capacity and Antibacterial Activity of Chulta (Dillenia indica Linn.) Fruits: Effects of Maturity Stage and Extraction Solvent

Abstract

Proximate compositions, phenolic compounds, antioxidant capacity and
antibacterial activity were determined for chulta (Dillenia indica) fruits and the effects of
maturity stage and extraction solvent were also investigated. Results revealed that fruit
size and color values (a*, b*, C* and h˚) of immature and mature chulta fruits were
significantly different. Immature fruits contained higher ash content but lower fat content
compared to mature fruits. Immature chulta fruits also had higher total phenolic content
in both water and ethanol extracts than mature fruits. Using HPLC-DAD/ESI-MS, 8 phenolic
compounds (syringic acid O-hexoside, syringic acid, vanillic acid hexoside, (+)-catechin or
(-)-epicatechin, procyanidin trimer type B, isoramnethin-3-O-hexoside, kaempferol-3,7-Ohexoside
or luteolin-3,7-O-hexoside and luteolin-7-O-glucuronide) were tentatively
identified in water extracts of chulta fruit, whereas only 3 phenolics (isoramnethin-3-Ohexoside,
kaempferol-3,7-O-hexoside or luteolin-3,7-O-hexoside and luteolin-7-Oglucuronide)
were found in ethanol extract. The results also showed that immature chulta
fruits exhibited higher DPPH scavenging capacity and antibacterial potential against
Escherichia coli and Staphylococcus aureus when compared to mature fruits. Finally, the
results from this study could be used to encourage the utilization of chulta fruits as
functional ingredients in healthy food or supplement production.