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Advisor(s)
Abstract(s)
The objective of this work was to characterize the
thistle flower in relation to the composition of phenolic
compounds and antioxidant activity, as well as the evalua-
tion of the stability of the phenols along the digestive tract. In
addition, the effect of drying temperature was evaluated and
the composition in polysaccharides was also studied. For
this, samples of thistle flower were lyophilized and dried at
40, 50 and 60 C. Methanol:acetic acid (98:2 v/v) and ace-
tone:water (60:40 v/v) extracts were obtained and analysed
for antioxidant activity, phenolic compounds, ortho-diphe-
nols, flavonoids, phenolic acids and polysaccharides, using
colorimetric methods, HPLC and GC-FID. The results
showed that the phenolic compounds and antioxidant
activity with ABTS or DPPH methods on thistle flower
decreased by 20, 34 and 72 %, respectively, with increasing
temperature from 40 to 60 C. The amount of compounds
available for intestinal absorption decreased along the gas-
trointestinal system, by 15–50 %. The presence of sugars
constituent of pectic polysaccharides was observed
(101.6–222.0 mg/g) as well as of hydroxybenzoic
(0.19–1.26 mg/g) and hydroxycinnamic acids
(1.57–5.59 mg/g). As a conclusion it was found that thistle
flower is rich in bioactive compounds with potential
importance for the human health.
Description
Keywords
Antioxidant activity Bioavailability Drying Phenolic Compounds Thistle Flower
Citation
Guiné, R. P. F., Pedro, A., Matos, J., Barracosa, P., Nunes, C., & Gonçalves, F. J. (2017). Evaluation of phenolic compounds composition, antioxidant activity and bioavailability of phenols in dried thistle flower. Journal of Food Measurement and Characterization, 11(1), 192-203. doi:10.1007/s11694-016-9386-0