| Abstrak/Abstract |
Rhodomyrtus tomentosa has been used as a traditional medicine for a long time in Southeast
Asia countries and also in Indonesia. It is believed that the phytochemical content of its fruit at different
levels of ripeness may affect its antioxidant activity. Therefore, this study aims to determine the
antioxidant activity, phenols and flavonoids contents, and their distribution in the leaves and fruits of
R. tomentosa at different levels of maturity. The antioxidant activity was determined using DPPH and
FRAP analysis. Furthermore, the total flavonoid and phenolic contents were analyzed using the
colorimetric and Folin–Ciocalteu methods. The distribution of secondary metabolites in the leaves or
fruits tissues was determined using histochemical analysis. Antioxidant capacity was analyzed using
DPPH and FRAP, and a comparable result was obtained. The highest antioxidant activity was
observed in the green fruit with the value of 1419.75 ± 3.48 and 1367.59 ± 9.12 μmol TE/g DW
for DPPH and FRAP, respectively. The highest TFC value observed in the young leaves and
green fruits of the ethanol extract was 96.375 ± 3.96 and 95.731 ± 5.42 mg QE/g DW,
respectively. The highest TPC was found in the red fruits 50.772 ± 7.46 mgAGE/g DW. The
histochemical analysis provided a clear distribution of flavonoid and phenolic within the leaves and
fruits. It was found that both compounds accumulated in the epidermis, mesophyll, vascular bundles,
secretory cavity, and parenchyma midrib of the leaves, and also in the exocarp and mesocarp endocarp,
secretory cavity, vascular bundles, seed, trichomes of the fruits. This study showed that young leaves
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AIMS Agriculture and Food Volume 7, Issue 2, 282–296.
and green fruits have a higher potency of being a natural source of antioxidants and flavonoid
compounds. |
