Naslov
The influence of sugar addition on stability of phenolics, flavonoids, anthocyanins and antioxidant activity in red grape juice

Autori
Kopjar, Mirela ; Piližota, Vlasta ; Nedić Tiban, Nela ; Babić, Jurislav ; Ačkar, Đurđica

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the 2008 Joint Central European Congress / Ćurić, Duška - Zagreb : Hrvatska gospodarska komora (HGK), 2008, 169-175

ISBN
978-953-6207-85-5

Skup
4 th Central European Congress on Food ; 6 th Croatian Congress on Food Technologists, Biotechnologists and Nutritionists

Mjesto i datum
Cavtat, Hrvatska, 15.05.2008. - 17.05.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
red grape juice; sugar addition; total phenols; anthocyanins; antioxidant activity

Sažetak
Stability of phenolics, flavonoids, anthocyanins and antioxidant activity in red grape juice and red grape juice with addition of sucrose, trehalose, glucose and fructose (5, 10 and 15 %) during storage of 3 weeks at 4 °C was investigated. Antioxidant activity was determined by FRAP and DPPH methods. Results showed that type of sugar and its concentration had, in juice samples more or less, influence on all investigated parameters. The highest retention of total phenolics was in grape juice with addition of 15 % sucrose (89.3 %) and 15 % fructose (88.7 %). The highest amount (15 %) of all added sugars caused the highest retention of total flavonoids (23.5-24.7 %). The highest retention of anthocyanins were in grape juice with addition of 15 % of trehalose (57.6 %) and 15 % glucose (51.51 %). Antioxidant activity, regardless of used method for determination, after one week of storage increased in all investigated samples. Antioxidant activity started to decrease after two weeks. After storage of 3 weeks the highest retention (80 %) was detected in the juice sample with addition of 15 % of glucose measured by FRAP method, than in the sample with addition of 15 % of trehalose measured by DPPH (24.3 %).

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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