Antioxidative Properties of Essential Spices in an Indonesian Non-Alcoholic Beverage ‘Bir Pletok’

Abstract

Clove, cinnamon and nutmeg are essential spices in Bir Pletok, a traditional non-alcoholic
Indonesian beverage. This study aimed to determine the antioxidant activities in different
aqueous extracts of clove, cinnamon and nutmeg available in Indonesia and Thailand.
Extraction was performed by boiling the mixture of spice and water (25% w/v) at 95-97°C
for 15-45 min. Total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl free radical
scavenging (DPPH), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance
capacity (ORAC), color (L*, a*, b*) and pH values of the extracts were determined.
Aqueous extracts of clove showed the highest TPC, DPPH, FRAP and ORAC, followed by
cinnamon and nutmeg (p≤0.05). Extending extraction time significantly increased the
antioxidative properties of the aqueous extract of all spices. Aqueous extracts of spice from
Indonesia exhibited significantly higher TPC and FRAP than those obtained in Thailand
(p≤0.05), but DPPH and ORAC were indifferent (p>0.05). The L*, a* and pH values of the spice
extracts were not affected neither by the origin nor extraction time. Meanwhile, b* values of
the extracts significantly increased with the length of extraction, and those of Indonesian
spices were about 40% higher than Thailand (p≤0.05). In conclusion, type and source of
spices as well as extraction time were the parameters that largely affected the antioxidative
properties of the hot water extracts. Thus, it might be possible to improve the potential health
benefits of Bir Pletok by optimizing the proportion of spices in the recipe and the length of
boiling, as well as ingredient sourcing.