Abstract Book - 3rd International Symposium on Medicinal Plants ...

number of TVC in the samples. The TVC in the samples added with SL alone, PE with SL, and
MVE 2 with SL decreased by 1.36, 1.35, and 2.42 log units after 21 days of storage. However,
addition of vegetable extracts alone did not cause reduction of microbial counts in the sausages
during storage. The sausage samples added with PE in combination with SL had less rancid odor
compared to the samples of other treatments. Therefore, the vegetable extract, PE in combination
with SL could be effectively used to extend shelf-life of the chinese-style sausage.
Key words: Antimicrobial,antioxidant, Polygonum odoratum, sodium lactate.
9.9 Antioxidant Potential of Some Medicinal Plants
P.R. Venskutonis 1 ., I. Šliumpaitė 1 ., M. Murkovic 2 ., and A. Zeb 2
1 Department of Food Technology, Kaunas University of Technology, Radvilın ı pl. 19, Kaunas,
LT-50254, Lithuania. 2 Institute for Food Chemistry and Technology, Graz University of
Technology, Petersgasse 12/2, A – 8010 Graz, Austria.
<strong>Abstract</strong>: Medicinal plants biosynthesize various compounds, including strong antioxidants,
which may be used as a promising source of natural food additives and healthy functional
ingredients. In this study radical scavenging activity of extracts isolated from such less investigated
previously plants as Betonica officinalis, Gratiola officinalis, Vincetoxicum lutea, Saponaria
officinalis and Astragallus glycyphyllos was evaluated using DPPH • and ABTS +• radical scavenging
assays. It was determined that the extracts from hedge hyssop (G. officinalis), wood betony (B.
officinalis) and swallowwort (V. lutea) possessed the highest radical scavenging acitivity in both
assays. Their antioxidant activity was much stronger than those of soapwort (S. officinalis) and
wild liquorice (A. glycyphyllos). The content of total amount of phenolic compounds measured by
Folin-Ciocalteu method correlated with the ability of plant extracts to scavenge free radicals. It was
found that the highest amount of phenolic compounds were in the plant extracts which effectively
inhibited DPPH • and ABTS +• free radicals. The most active species G. officinalis, B. officinalis and
V. lutea were selected for further studies, which were focused on phytochemical composition of
the extracts as well as antioxidant activities of the separated constituents. An on-line HPLC-DPPH •
method was used for this purpose. The technique enabled selective detection and identification of
individual radical scavenging compounds without any prior off-line and time consuming
chromatographic steps. It was determined that one of the main compounds possessing antioxidant
activity in B. officinalis and V. lutea was chlorogenic acid. Moreover, the acetonic extract of
swallowwort contained other 5 compounds, namely apigenin-7-O-glucoside, ferulic acid,
cynaroside, luteolin-7-O-gentiobioside and quercetin-3-O-glucoside. The methanolic extract of this
plant contained less compounds possessing antioxidant activity. Three compounds were identified
in the mentioned extract, namely chlorogenic acid, isoquercetin and luteolin-7-O-gentiobioside.
The identification of the chemical constituents from hedge hyssop was more complicated; however
it was observed that the main compounds possessing antioxidant activity were hydrocinnamic acid
derivatives. Furthermore, it was found that the extracts from wood betony contain these
compounds as well. The identified constituents in wood betony were luteolin-7-O-glucoside,
vitexin, luteolin-7-O-glucuronide and apigenin-7-O-p-coumaroylglucoside.
Key words: Antioxidant potential, medicinal plants.
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