Voltammetric and spectroscopic determination of polyphenols and antioxidants in ginger (Zingiber officinale Roscoe) - PubMed (original) (raw)

Voltammetric and spectroscopic determination of polyphenols and antioxidants in ginger (Zingiber officinale Roscoe)

Nursyahidah Alawiyah Idris et al. Heliyon. 2019.

Abstract

Ginger (Zingiber officinale) is widely consumed as an important spice or a common condiment in food and beverages. This study focuses on the determination of pungent and bioactive components in ginger and their antioxidant activity using voltammetric and spectroscopic methods. Gas chromatography-mass spectroscopy analysis revealed that the major components of the pungent compounds were zingerone, shogaols, gingerols, paradols, wikstromol, and carinol. Using spectroscopic methods, the antioxidant capacity of ginger aqueous extract was found to be 16.0 μmol gallic acid equivalent (GAE) per gram of ginger extract, and the total phenolic and flavonoid content was estimated to be 7.8 mg GAE/g ginger extract and 15.4 mg Quercetin equivalent (QE) per gram of ginger extract, respectively. Electroanalytical quantification estimated the antioxidant capacity of the ginger infusion to be 23.5 μmol GAE/g ginger extract, which is slightly higher than that estimated using chemical assay. The results may provide useful information for the development of ginger processing and utilization as a flavoring agent, and for our understanding of ginger as a source of natural antioxidants.

Keywords: Chemistry; Food analysis; Food science; Natural product chemistry.

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Figures

Fig. 1

Fig. 1

(A) Overlaid differential pulse voltammograms for different concentrations of gallic acid in 0.1 M acetate buffer (pH 3.8) measured at 3-mm diameter glassy carbon electrode with modulation amplitude of 70 mV and scan rate of 20 mV/s. Inset: peak current as a function of concentration of gallic acid. (B) The differential pulse voltammograms of ginger extract (1000 ppm) in 0.1 M acetate buffer pH 6.5 measured at the same conditions.

Fig. 2

Fig. 2

Cyclic voltammograms of double distilled water (dotted line) and ginger extract in double distilled water (solid line) measured at 100 mV/s at 3-mm diameter polished glassy carbon electrode.

Fig. 3

Fig. 3

(A) Cyclic voltammograms of ginger extract (1000 ppm) of infusion in 0.1 M acetate buffer (pH 4) measured from 5 to 200 mV/s at a 3-mm polished glassy carbon electrode. (B) A plot of anodic (filled circles, R2 = 0.9689) and cathodic (open circles, R2 = 0.9833) peak current against square root of scan rates.

Fig. 4

Fig. 4

(A) Cyclic voltammograms of 1000 ppm ginger extract in 0.1 M acetate buffer at pH (a) 2.2, (b) 3.4, (c) 4, (d) 5, (e) 6, and (f) 7 measured at 100 mV/s at 3-mm diameter polished glassy carbon electrode. (B) A graph of E° (V) as a function of pH, and (C) A plot of anodic (filled circles) and cathodic (open circles) peak current as a function of pH.

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References

    1. Larsen K., Ibrahim H., Khaw S.H., Saw L.G. Natural history publications (Borneo); Singapore: 1999. Gingers of Peninsular Malaysia and Singapore.
    1. Wang W.H., Wang Z.M. Studies of commonly used traditional medicine-ginger. Zhongguo Zhongyao Zazhi. 2005;30:1569–1573. - PubMed
    1. Nicoll R., Henein M.Y. Ginger (Zingiber officinale Roscoe): a hot remedy for cardiovascular disease? Int. J. Cardiol. 2009;131:408–409. - PubMed
    1. Townsend E.A., Siviski M.E., Zhang Y., Xu C., Hoonjan B., Emala C.W. Effects of ginger and its constituents on airway smooth muscle relaxation and calcium regulation. Am. J. Respir. Cell Mol. Biol. 2013;48:157–163. - PMC - PubMed
    1. Bhandari U., Kanojia R., Pillai K.K. Effect of ethanolic extract of Zingiber officinale on dyslipidaemia in diabetic rats. J. Ethnopharmacol. 2005;97:227–230. - PubMed

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