Page 58 - D:\Video IPSyoFS22\

Determining the effect of different drying methods on antioxidant properties in jarum tujuh
bilah (Pereskia bleo) leaf

1
1
1 Zulkipli Nurain Nabilah, Lob Suhaizan, Mubarak Aidilla *

1 Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu,
21030 Kuala Nerus, Terengganu, Malaysia.

* Corresponding author: aidilla@umt.edu.my

Abstract:
Jarum tujuh bilah (Pereskia bleo) are highly cultivated and widely used for medicinal purposes. P. bleo
leaf has been reported to contain phytochemicals that includes phenolics and flavonoids. Despite being
a common step in processing of raw leaf material that enhances its shelf life, drying process may affect
the bioactive compounds in the leaf. Therefore, this study determines the effects of different drying
techniques on antioxidant properties of P. bleo leaves. The drying methods include shade drying (SD),
oven drying (OD), microwave drying (MD) and freeze-drying (FD). Total phenolic content (TPC) of
the dried leaves extracts were determined using Folin-Ciocalteu method and total flavonoid content
(TFC) were determined using aluminum chloride colorimetric assay. Antioxidant capacities were
analysed with ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH)
radical scavenging assay. This study showed that P. bleo leaves dried with MD had a significantly higher
content of TPC (76.74±1.37 mg GAE/g dry extract) and TFC (33.99±0.36 mg QE/g dry extract)
compared to the other drying techniques (p<0.05). P. bleo leaves dried with MD also recorded the
highest value of antioxidant activity measured by FRAP (62.66±0.10 µg TE/g dry extract) and DPPH
(91.62 %), when compared to the other drying techniques (p<0.05). The DPPH inhibitory concentration
(IC50) values was recorded as 76.90±1.06 µg/mL for P. bleo leaf dried with MD. The inhibitory
concentration (IC50) values of were measured and compared with the synthetic antioxidant, BHT. P.
bleo dried with MD showed the most potent IC50 value of that was recorded at 76.90±1.06 µg/ml which
was the BHT (52.23±7.02 µg/ml). MD was found to be the optimal drying technique to minimize losses
of the antioxidant properties from the P. bleo leaf. This study also shows a potential for P. bleo to be
utilized as a source of natural antioxidant in the nutraceutical industry.

Keywords: Pereskia bleo, Antioxidant, Drying techniques, Microwave drying, Medicinal plant