Naslov
Optičke test trakice za mjerenje antioksidativnog kapaciteta pomoću imobiliziranog slobodnog radikala 2, 2-difenil-1-pikrilhidrazila (DPPH)
(Optical Test Strips for Antioxidative Capacity Based on 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH) Free Radical)

Autori
Murković Steinberg, Ivana ; Milardović, Stjepan

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XIX hrvatski skup kemičara i kemijskih inženjera, Kniga sažetaka / Rapić, V. ; Rogošić, M. - Zagreb : Sveučilišna tiskara, 2005

Skup
XIX hrvatski skup kemičara i kemijskih inženjera

Mjesto i datum
Opatija, Hrvatska, 24.04.2005. - 27.04.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Antioxidant; DPPH; Optical strips

Sažetak
The feasibility of developing optical test strips based on immobilised chromogenic free radicals for the assessment of antioxidative capacity has been studied. A stable lipophilic chromogenic radical DPPH• (2, 2-diphenyl-1-picrylhydrazyl radical) was immobilised in plasticised PVC films and screened for suitability as indicator of antioxidative capacity. The free radical DPPH• is reduced by hydrogen donating antioxidant (AH) to the corresponding hydrazine, and changes its colour from purple to yellow. The reaction between stable chromogenic radical DPPH• and antioxidants is monitored spectrophotometrically at 520 nm. The spectrophotometric characterisation of the polymer films containing immobilised free radicals was performed, and the response of the immobilised free radicals toward standard antioxidants was studied. It has been demonstrated that the immobilised radicals retain their reactivity towards antioxidants. Polymer films containing immobilised DPPH• radical respond to standard antioxidants in water solutions by changing colour irreversibly from purple (absorption maximum at 520 nm) to yellow. The initial slopes of the response curves to different concentrations of the phenolic antioxidant gallic acid (50 mM to 0.1 mM) gave a linear calibration plot in a 1 minute exposure cuvette test. The polymer films demonstrated sensitivity to beverage and food samples known to contain antioxidants, such as black and green tea, coffee, red wine, fruit juice, olive oil and sunflower oil.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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