Optimisation of microwave-assisted extraction for functional properties of Vitis coignetiae extract by response surface methodology.
BACKGROUND
Consumer preference for selection of natural substances, with their safe and beneficial effects on the human body as well as various physiological efficacies, is increasing. In this study, response surface methodology (RSM) was used to monitor the extraction characteristics of Vitis coignetiae (wild grape) and thereby optimise the functional properties of the resulting extract.


RESULTS
A maximum total polyphenol content (TPC) of 415.74 mg per 100 g was obtained at a microwave power (MWP) of 102.36 W, an ethanol concentration (ETC) of 42.62% (by volume) and an extraction time (EXT) of 12.35 min. Electron-donating ability (EDA) reached a maximum of 69.20% at 125.65 W MWP, 41.81% ETC and 13.65 min EXT. The maximum nitrite-scavenging ability (NSA) obtained was 87.50% at 119.13 W MWP, 37.41% ETC and 13.20 min EXT. Superoxide dismutase (SOD) showed a maximum pseudo-activity (SDA) of 56.74% at 69.54 W MWP, 94.88% ETC and 10.32 min EXT. The effect of ETC was most prominent among the studied factors.


CONCLUSIONS
Based on the superimposition of four-dimensional response surfaces with respect to TPC, EDA, NSA and SDA, the optimum ranges of extraction conditions were 70-150 W MWP, 30-50% ETC and 8-18 min EXT.
Korea Food Research Institute, Songnam, South Korea.
Hyun-Ku
HK
Kim
Jeong-Ryong
JR
Do
Tae-Soo
TS
Lim
Kashif
K
Akram
Sung-Ran
SR
Yoon
Joong-Ho
JH
Kwon
D000975:Antioxidants / Q000032:analysis* / Q000378:metabolism; D003627:Data Interpretation, Statistical; D005638:Fruit / Q000737:chemistry*; D055951:Functional Food; D006801:Humans; D008872:Microwaves; D009573:Nitrites / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis*; D013482:Superoxide Dismutase / Q000378:metabolism; D027843:Vitis / Q000737:chemistry*
D000975:Antioxidants; D009573:Nitrites; D010936:Plant Extracts; D059808:Polyphenols; D013482:Superoxide Dismutase