Automatic sequential determination of the hydrogen peroxide scavenging activity and evaluation of the antioxidant potential by the 2,2 '-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay in wines by sequential injection analysis

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Pinto, PCAG (Author) Other; Saraiva, MLMFS (Author) FFUP; Reis, S (Author) FFUP; Lima, JLFC (Author) FFUP

Journal

Title: Analytica Chimica Acta

Vol. 531 No. 2

Pages: 25-32

ISSN: 0003-2670

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 33 Citations

Scopus - 38 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-000-4PE

DOI: 10.1016/j.aca.2004.10.005

Abstract (EN): An automatic system that performs two analytical procedures, allowing the evaluation of the relative antioxidant capacity of wine samples, was developed. Automation was carried out using a sequential injection analysis (SIA) system that allowed, thanks to its versatility, the development of two methodologies. One is based on the decolorization assay of the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, using a spectrophotometric detector. A second methodology allowed the evaluation of the hydrogen peroxide scavenging activity by measuring the oxidation of homovanylic acid (HVA) to its fluorescent dimer, using a fluorescent detector. The developed automatic methodologies were evaluated using trolox as standard and subsequently using other antioxidant substances as gallic acid, caffeic acid, ascorbic acid, catechin and taxifolin which are abundant in wine and whose antioxidant activities were compared to that shown by trolox. The spectrophotometric and fluorimetric assays showed linearity intervals between 0.001 and 0.01 mM, and 0.001 and 0.008 mM of trolox, respectively. The evaluation of the antioxidant power of 20 white and red wine samples, from different Portuguese wine producing regions, was carried out sequentially, in the automatic system. The results were expressed in trolox equivalent antioxidant capacity (TEAC) and presented, for the ABTS and hydrogen peroxide scavenging activity methodologies, detection limits of 8.4 x 10(-7) and 1.4 x 10(-4) mM and relative standard deviation (R.S.D. (%)) in the range 0.6-2.4 and 1-1.8, respectively.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8