FLAVONOID CONTENT AND ANTIOXIDANT ACTIVITY OF KRACHAI-DUM (Kaempferia Parviflora) WINE

Wine fermentation was conducted with three different preparations of Krachai-Dum using tamarind juice as a base composition. In the first preparation, pieces of sliced Krachai-Dum were fermented with tamarind juice.  For the second preparation, Krachai-Dum extracts were mixed with tamarind juice and used for fermentation process.  The third preparation was performed by adding pieces of sliced Krachai-Dum into fermented tamarind wines during aging process.  Three types of Krachai-Dum; unpeeled Krachai-Dum slices, peeled Krachai-Dum slices and Krachai-Dum skin were used separately to prepare Krachai-Dum wine. Tamarind juice without Krachai-Dum was used as control.  After fermentation, Krachai-Dum wines were kept at 4 ºC for aging process.  Total phenolic compounds, flavonoid contents and antioxidant activity were examined in all samples.  Total phenolic compounds ranged from 107.00 ± 9.27 to 306.62 ± 6.21 mgGAE/l. Seven flavonoids were detected in all preparations of Krachai-Dum wine except in the control as follows: 5-hydroxy-7-methoxyflavone, 5-hydroxy-3,7,3′,4′-tetramethoxyflavone, 5-hydroxy- 3,7,4′-trimethoxy flavone, 5,7,4′-trimethoxyflavone, 5-hydroxy-3,7-dimethoxyflavone, 3,5,7,3′,4′-penta  methoxyflavone and 5,7-dimethoxyflavone.  Among these, 3,5,7,3′,4′-pentamethoxyflavone was the major component found in all samples and 5-hydroxy-3,7,3′,4′-tetramethoxyflavone was detected in lowest amount.  The total flavonoid contents ranged from 9.59 to 24.41 mg/100ml wine.  The wine using Krachai-Dum skin showed higher flavonoid contents than those using peeled or unpeeled pieces.  The highest total flavonoid content (24.41 mg/100ml wine) was found in Krachai-Dum wine prepared by adding Krachai-Dum skin to tamarind wine during the aging process of 4 months.  In vitro antioxidant activity of wine samples before and after 1, 2, 3, 4 months of aging process was examined by DPPH and FRAP methods.  Antioxidant activity of wine samples by both methods showed similar results that the activities are higher in Krachai-Dum wine prepared by fermented peeled or unpeeled Krachai-Dum with tamarind juice than those prepared by Krachai-Dum extracts.  Phenolic contents and antioxidant activities in all conditions were in the same direction. The results suggested that the phenolic compounds may play an important role in the antioxidant effect in Krachai-Dum wine.  However, the total flavonoid content did not correlate with the antioxidant activity of the sample wines.   

Keywords: Kracahi-Dum wine, Kaempferia parviflora, antioxidant, 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP)

Corresponding author: E-mail: sukanda@kku.ac.th