Total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone.
The total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone, were determined. Grape seed and green tea were analyzed for their phenolic constituents using high-performance liquid chromatography. The total phenolics of the plant extracts, determined by the Folin-Ciocalteu method, ranged from 24.8 to 92.5 mg of chlorogenic acid equivalent/g dry material. The antioxidant activities of methanolic extracts determined by conjugated diene measurement of methyl linoleate were 3.4-86.3%. The antioxidant activity of the extracts using chicken fat by an oxidative stability instrument (4.6-10.2 h of induction time) followed a similar trend in antioxidant activity as determined by the Folin-Ciocalteu method. Seven phenolics in grape seed and green tea extracts were identified that ranged from 15.38 to 1158.49 and 18.3 to 1087.02 mg/100 g of extract, respectively. Plant extracts such as green tea and grape seed extracts can be used to retard lipid oxidation in a variety of food products.
Department of Food Science, University of Arkansas, 2650 North Young Avenue, Fayetteville, Arkansas 72704, USA.
Taha M
TM
Rababah
Navam S
NS
Hettiarachchy
Ronny
R
Horax
D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D028241:Camellia sinensis / Q000737:chemistry*; D028041:Centella / Q000737:chemistry; D020939:Zingiber officinale / Q000737:chemistry; D020441:Ginkgo biloba / Q000737:chemistry; D006873:Hydroquinones / Q000032:analysis; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D027542:Rosmarinus / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D029910:Trigonella / Q000737:chemistry*; D014810:Vitamin E / Q000032:analysis; D027843:Vitis / Q000737:chemistry*
D000975:Antioxidants; D006873:Hydroquinones; D010636:Phenols; D010936:Plant Extracts; D014810:Vitamin E; C018855:2-tert-butylhydroquinone